TAChart Demos: what changed

Revision 1 to 2. Removed lines have a minus sign; added lines have a plus sign.

Old	New		Line
1	1		## Introduction
2	2
3	3		TAChart is Lazarus' powerful charting library. It consists of numerous classes and declarations distributed over some 50 units. New users may be overwhelmed by the complexity of usage, and even experienced charters still find gems from time to time.
4	4
5	5		In order to demonstrate the possibilities of TAChart a variety of demo projects has been written. They are stored in the directory `components/tachart/demo` of the Lazarus installation. However, there is no overview of these examples, and it is often quite cumbersome to find a certain application of interest. Therefore, it is the intention of this wiki page to provide some kind of catalogue of the TAChart demos. Each demo project will be accompanied by a short description and a screen shot of the program output.
6	6
7	7		## Gallery
8	8
9	9		Click on the captions to go to the description of that particular demo project. Click on the thumbnail to see the screenshot at normal size.
10	10
11	11		[`file:zdemo.png`](file:zdemo.png)` \| `[[TAChart Demos\|3d]]\
12	12		[`file:aggpasdemo.png`](file:aggpasdemo.png)` \| `[[TAChart Demos\|aggpas]]\
13	13		[`file:TAChart_Animate_Demo.jpg`](file:TAChart_Animate_Demo.jpg)` \| `[[TAChart Demos\|animate]]\
14	14		[`file:axis_customized_marks.png`](file:axis_customized_marks.png)` \| `[[TAChart Demos\|axis (Page "Customized marks")]]\
15	15		[`file:axis_axis_groups.png`](file:axis_axis_groups.png)` \| `[[TAChart Demos\|axis (Page "Axis groups")]]\
16	16		[`file:axis_submarks.png`](file:axis_submarks.png)` \| `[[TAChart Demos\|axis (Page "Submarks")]]\
17	17		[`file:axis_date_and_time.png`](file:axis_date_and_time.png)` \| `[[TAChart Demos\|axis (Page "Date and time")]]\
18	18		[`file:axis_intervals.png`](file:axis_intervals.png)` \| `[[TAChart Demos\|axis (Page "Intervals")]]\
19	19		[`file:axis_position.png`](file:axis_position.png)` \| `[[TAChart Demos\|axis (Page "Position")]]\
20	20		[`file:axisalign.png`](file:axisalign.png)` \| `[[TAChart Demos\|axisalign]]\
21	21		[`file:axistransf_linear.png`](file:axistransf_linear.png)` \| `[[TAChart Demos\|axistransf (Page "Linear")]]\
22	22		[`file:axistransf_indep_scale.png`](file:axistransf_indep_scale.png)` \| `[[TAChart Demos\|axistransf (Page "Independent scale")]]\
23	23		[`file:axistransf_logarithm.png`](file:axistransf_logarithm.png)` \| `[[TAChart Demos\|axistransf (Page "Logarithm")]]\
24	24		[`file:axistransf_normal_dist.png`](file:axistransf_normal_dist.png)` \| `[[TAChart Demos\|axistransf (Page "Normal distribution")]]\
25	25		[`file:axistransf_userdefined.png`](file:axistransf_userdefined.png)` \| `[[TAChart Demos\|axistransf (Page "User defined")]]\
26	26		[`file:barshapesdemo.png`](file:barshapesdemo.png)` \| `[[TAChart Demos\|barserieshapes]]\
27	27		[`file:basicdemo.png`](file:basicdemo.png)` \| `[[TAChart Demos\|basic]]\
28	28		[`file:bgrademo.png`](file:bgrademo.png)` \| `[[TAChart Demos\|bgra]]\
29	29		[`file:charteditor_dialog.png`](file:charteditor_dialog.png)` \| `[[TAChart Demos\|charteditordemo]]\
30	30		[`file:chartsource_basic.png`](file:chartsource_basic.png)` \| `[[TAChart Demos\|chartsource (Page "Basic")]]\
31	31		[`file:chartsource_statistics.png`](file:chartsource_statistics.png)` \| `[[TAChart Demos\|chartsource (Page "Statistics")]]\
32	32		[`file:chartsource_derivative.png`](file:chartsource_derivative.png)` \| `[[TAChart Demos\|chartsource (Page "Derivative")]]\
33	33		[`file:chartsource_sorting.png`](file:chartsource_sorting.png)` \| `[[TAChart Demos\|chartsource (Page "Sorting")]]\
34	34		[`file:clonedemo-series.png`](file:clonedemo-series.png)` \| `[[TAChart Demos\|clone (Page "Series")]]\
35	35		[`file:clonedemo-charts.png`](file:clonedemo-charts.png)` \| `[[TAChart Demos\|clone (Page "Charts")]]\
36	36		[`file:combodemo.png`](file:combodemo.png)` \| `[[TAChart Demos\|combobox]]\
37	37		[`file:distancedemo-main.png`](file:distancedemo-main.png)` \| `[[TAChart Demos\|distance (Page "Main")]]\
38	38		[`file:distancedemo-fit.png`](file:distancedemo-fit.png)` \| `[[TAChart Demos\|distance (Page "Fit")]]\
39	39		[`file:eventsdemo.png`](file:eventsdemo.png)` \| `[[TAChart Demos\|events]]\
40	40		[`file:extentdemo.png`](file:extentdemo.png)` \| `[[TAChart Demos\|extent]]\
41	41		[`file:fitdemo.png`](file:fitdemo.png)` \| `[[TAChart Demos\|fit]]\
42	42		[`file:funcdemo-domain.png`](file:funcdemo-domain.png)` \| `[[TAChart Demos\|func (Page "Domain")]]\
43	43		[`file:funcdemo-colormap.png`](file:funcdemo-colormap.png)` \| `[[TAChart Demos\|func (Page "Color map")]]\
44	44		[`file:funcdemo-spline.png`](file:funcdemo-spline.png)` \| `[[TAChart Demos\|func (Page "Spline")]]\
45	45		[`file:funcdemo-autoyextent.png`](file:funcdemo-autoyextent.png)` \| `[[TAChart Demos\|func (Page "Auto y extent")]]\
46	46		[`file:funcdemo-parametric.png`](file:funcdemo-parametric.png)` \| `[[TAChart Demos\|func (Page "Parametric")]]\
47	47		[`file:html_demo.png`](file:html_demo.png)` \| `[[TAChart Demos\|html]]\
48	48		[`file:legenddemo-page1.png`](file:legenddemo-page1.png)` \| `[[TAChart Demos\|legend (Page "Basics")]]\
49	49		[`file:legenddemo-page2.png`](file:legenddemo-page2.png)` \| `[[TAChart Demos\|legend (Page "OwnerDrawn"]]\
50	50		[`file:linedemo-fast.png`](file:linedemo-fast.png)` \| `[[TAChart Demos\|line (Page "Fast drawing")]]\
51	51		[`file:linedemo-pointers.png`](file:linedemo-pointers.png)` \| `[[TAChart Demos\|line (Page "Pointers")]]\
52	52		[`file:linedemo-customdrawnpointer.png`](file:linedemo-customdrawnpointer.png)` \| `[[TAChart Demos\|line (Page "Customdrawn pointer")]]\
53	53		[`file:linedemo-ongetpointerstyle.png`](file:linedemo-ongetpointerstyle.png)` \| `[[TAChart Demos\|line (Page "OnGetPointerStyle event")]]\
54	54		[`file:linedemo-oscilloscope.png`](file:linedemo-oscilloscope.png)` \| `[[TAChart Demos\|line (Page "Oscilloscope")]]\
55	55		[`file:linedemo-coloreach.png`](file:linedemo-coloreach.png)` \| `[[TAChart Demos\|line (Page "Color each data point")]]\
56	56		[`file:listboxdemo.png`](file:listboxdemo.png)` \| `[[TAChart Demos\|listbox]]` `\
57	57		[`file:liveview.png`](file:liveview.png)` \| `[[TAChart Demos\|liveview, liveview-paned]]\
58	58		[`file:multidemo-bubble.png`](file:multidemo-bubble.png)` \| `[[TAChart Demos\|multi (Page "Bubble")]]` `\
59	59		[`file:multidemo-stacked.png`](file:multidemo-stacked.png)` \| `[[TAChart Demos\|multi (Page "Stacked")]]` `\
60	60		[`file:multidemo-boxwhisker.png`](file:multidemo-boxwhisker.png)` \| `[[TAChart Demos\|multi (Page "Box-and-Whiskers")]]` `\
61	61		[`file:multidemo-ohlc.png`](file:multidemo-ohlc.png)` \| `[[TAChart Demos\|multi (Page "OHLC")]]` `\
62	62		[`file:multidemo-field.png`](file:multidemo-field.png)` \| `[[TAChart Demos\|multi (Page "Field")]]` `\
63	63		[`file:nandemo.png`](file:nandemo.png)` \| `[[TAChart Demos\|nan]]` `\
64	64		[`file:navigatedemo.png`](file:navigatedemo.png)` \| `[[TAChart Demos\|navigate]]` `\
65	65		[`file:noguidemo.png`](file:noguidemo.png)` \| `[[TAChart Demos\|nogui]]` `\
66	66		[`file:opengldemo.png`](file:opengldemo.png)` \| `[[TAChart Demos\|opengl]]` `\
67	67		[`file:panesdemo.png`](file:panesdemo.png)` \| `[[TAChart Demos\|panes]]` `\
68	68		[`file:printdemo.png`](file:printdemo.png)` \| `[[TAChart Demos\|print]]` `\
69	69		[`file:radialdemo_pie.png`](file:radialdemo_pie.png)` \| `[[TAChart Demos\|radial (page "Pie")]]` `\
70	70		[`file:radialdemo_polar.png`](file:radialdemo_polar.png)` \| `[[TAChart Demos\|radial (page "Polar")]]` `\
71	71		[`file:rotatedemo.png`](file:rotatedemo.png)` \| `[[TAChart Demos\|rotate]]` `\
72	72		[`file:savedemo.png`](file:savedemo.png)` \| `[[TAChart Demos\|save]]\
73	73		[`file:scriptdemo.png`](file:scriptdemo.png)` \| `[[TAChart Demos\|script]]\
74	74		[`file:toolsdemo.png`](file:toolsdemo.png)` \| `[[TAChart Demos\|tools]]\
75	75		[`file:wmfdemo.png`](file:wmfdemo.png)` \| `[[TAChart Demos\|wmf]]
76	76
77	77		## Demo folders
78	78
79	79		### 3d
80	80
81	81		[thumbnail\|upright 1.5](/wiki-images/4/4d/Zdemo.png) The project `zdemo` in the folder `3d` illustrates creation of a simple 3d effect in TAChart. Some series types have a property `Depth` allowing to extrude the series into the third dimension. Using the property `ZPosition` the series can be "shifted" back and forth into the depth dimension. The same property allows to move the axes and the grid to the front.\
82	82
83	83		### aggpas
84	84
85	85		[thumbnail\|upright 1.5](/wiki-images/1/1a/Aggpasdemo.png) For improved rendering quality, TAChart can take advantage of the fast and powerful [AggPas](http://www.crossgl.com/aggpas/) library with anti-aliased drawing and subpixel accuracy. The project `aggpasdemo` shows the necessary code to achieve this:
86	86
87	87		- Add a `TChartGUIConnectorAggPas` to the form and assign it to the property `GUIConnector` of the form
88	88		- Or, use a `TPaintbox` and use the code given in `TForm1.PaintBox1Paint` in its `OnPaint` event.
89	89
90	90		Note that this feature is not yet available in Lazarus 1.2 and requires the trunk version. Packages `AggPasLCL` and `TACharstAggPas` are needed to compile the demo.\
91	91
92	92		### animate
93	93
94	94		[thumbnail\|upright 1.5](/wiki-images/a/a3/TAChart_Animate_Demo.jpg) The `animatedemo` presents animation of a bar chart. The main animation work is done by a `TCustomAnimatedChartSource` created at runtime and its `OnGetItem` event.\
95	95
96	96		### axis
97	97
98	98		[thumbnail\|upright 1.5](/wiki-images/8/8b/Axis_customized_marks.png) The project "axis" shows some fundamental and advanced aspects of axis formatting and layout in a multi-page form:
99	99
100	100		Page Customized marks demonstrates how painting of the marks of an axis can be controlled by modifying their properties, such as `Marks.LabelBrush`, `Marks.Frame`, or `Marks.LabelFont`. Highlighting of individual marks can be done by assigning a handler to the axis event `OnMarksToText`:
101	101
102	102		``` pascal
103	103		procedure TForm1.ChartCustomMarksAxisList1MarkToText(var AText: String; AMark: Double);
104	104		begin
105	105		if AMark = 3 then
106	106		AText := '' + AText + '';
107	107		end;
108	108		```
109	109
110		-	\
111	110		[thumbnail\|upright 1.5](/wiki-images/6/6a/Axis_axis_groups.png) In page Axis groups it is shown how a chart layout with multiple axes can be created. The [[TAChart Tutorial: Multiple Panes in one Chart]] explains the required steps in detail.
112	111
113	112		In the demo, the axes and required axis transformations are created at runtime.\
114	113		[thumbnail\|upright 1.5](/wiki-images/3/3d/Axis_submarks.png) In the next page, Submarks, a minor axis is used along the x axis, and smaller labels are drawn for each tick of the minor axis. This effect is achieved by adding an additional axis to the property `Minors`. Minor axes have their own set of marks and labels.\
115	114		[thumbnail\|upright 1.5](/wiki-images/7/73/Axis_date_and_time.png) Displaying an axis with date and time data is the subject of page Date and time. The series displays random data for every hour in a 10-year date range. Zoom in by clicking with the left, zoom out by clicking with the right mouse button. For every zoom level the TDateTimeIntervalChartSource manages to displays reasonable labels along the x axis.\
116	115		[thumbnail\|upright 1.5](/wiki-images/f/ff/Axis_intervals.png) The most prominent feature of the demo in page Intervals is that the same y data are displayed on several axes with different settings of the `Intervals` property. The x axis demonstrates how the range of displayed labels can be limited by means of the axis property `Marks.Range`.\
117	116		[thumbnail\|upright 1.5](/wiki-images/6/66/Axis_position.png) Page Position demonstrates that axes do not have to be at the edge of a chart. In plots of mathematical function, for examples, the axes usually run through the origin at x=0 and y=0. Modifying the property `Position` of an axis allows to place it at any position. The demo shows also how an additional axis can be added at the chart edge.
118	117
119	118		### axisalign
120	119
121	120		[thumbnail\|upright 1.5](/wiki-images/8/86/Axisalign.png) In new TAChart versions after Lazarus 1.2.6, the chart axis has a new property `LabelSize` which - if different from `0` - overrides the automatic axis positioning mechanism. Therefore, this property can be used to align the axis lines of charts which are stacked or positioned side-by-side and in which the axis labels have different lengths.\
122	121
123	122		### axistransf
124	123
125	124		[thumbnail\|upright 1.5](/wiki-images/9/97/Axistransf_linear.png) The subject of the project "axistransf" are axis transformations which are the key to non-linear or distorted axis scales. Several charts are combined into a multi-paged form.
126	125
127	126		The chart on page Linear shows two temperature curves which are displaced for better clarity. The summer temperatures are shown as a red curve, the labels are at the left y axis; the winter temperatures are shown as a blue curve (and overlayed bar series) and have their labels on the right y axis. Both axes cover only part of the available space to separate the data.
128	127
129	128		This effect can be achieved by using auto-scale axis transformations.
130	129
131		-	\
132	130		[thumbnail\|upright 1.5](/wiki-images/f/f4/Axistransf_indep_scale.png) The demo Independent scale covers the same subject.
133	131
134	132		See [[TAChart Tutorial: Multiple Panes in one Chart]] for a detailed explanation of the steps required.\
135	133		[thumbnail\|upright 1.5](/wiki-images/2/2b/Axistransf_logarithm.png) A plot with logarithmic axis is displayed on page Logarithm. The striped background layout is achieved by means of a `TChartStyles` component.\
136	134		[thumbnail\|upright 1.5](/wiki-images/7/73/Axistransf_normal_dist.png) Page Normal distribution shows a series with random data, their statistical distribution follows a Normal Distribution. Using a `TCumulNormDistrAxisTransform` the cumulated probability distribution can be distorted to follow a straight line.\
137	135		[thumbnail\|upright 1.5](/wiki-images/c/ce/Axistransf_userdefined.png) The chart on page User defined contains a purple vertical line which acts like a magnifier: The series is zoomed horizontally in the vicinity around this line. Dragging the line allows to blow up any part of the series.
138	136
139	137		This local zoom effect is achieved by means of a `TUserDefinedAxisTransform`. In this transform, the axis transformation is defined by the handler of the event `OnAxisToGraph`.\
140	138
141	139		### barseriesshapes
142	140
143	141		[thumbnail\|upright 1.5](/wiki-images/e/e4/Barshapesdemo.png) Demonstrates usage of alternative bar shapes in 3D TBarSeries.\
144	142
145	143		### basic
146	144
147	145		[thumbnail\|upright 1.5](/wiki-images/3/3d/Basicdemo.png) Basic operation with charts and series is demonstrated in the `basicdemo` project. The demo shows
148	146
149	147		- how to create a series at runtime and add it to the chart
150	148		- how to add data to a series (`series.AddXY(...)`)
151	149		- how to clear series (`Chart1.ClearSeries`)
152	150		- how to change the z position of a series (`TForm1.BringToFront`)
153	151		- how to show/hide axes, axis grid, titles and the legend
154	152		- how to invert the axis direction
155	153		- how to show a crosshair marker. Note, however, that usage of the reticule is deprecated now, use [[TAChart documentation\|zoom tools]] instead.
156	154
157		-	\
158		-
159	155		### bgra
160	156
161	157		[thumbnail\|upright 1.5](/wiki-images/4/4e/Bgrademo.png) For improved rendering quality, TAChart can take advantage of the fast and powerful [[BGRABitmap]] library with anti-aliased drawing and subpixel accuracy. The project `bgrademo` shows the necessary code to achieve this:
162	158
163	159		- Add a `TChartGUIConnectorBGRA` to the form and assign it to the property `GUIConnector` of the form
164	160		- Or, use a `TPaintbox` and use the code given in `TForm1.PaintBox1Paint` in its `OnPaint` event.
165	161
166	162		Packages `bgrabitmappack` and `TAChartBgra` are needed to compile the demo.
167	163
168	164		> Note: There is a special wiki page [[BGRABitmap tutorial TAChart\|BGRABitmap Tutorial TAChart]] giving step-by-step instructions how to create a chart like the one in the image at the right.
169	165
170		-	\
171		-
172	166		### charteditordemo
173	167
174	168		[thumbnail\|upright 1.5](/wiki-images/f/f0/Charteditor_dialog.png) The charteditordemo project shows a gui how the user could interactively change most elements of a chart. Besides the `TDataPointClickTool`, the project relies strongly on the dedicated chart tools `TTitleFootClickTool`, `TAxisClickTool` and `TLegendClickTool` which were introduced in Lazarus v2.1.\
175	169
176	170		### chartsource
177	171
178	172		The demo project chartsource illustrates various use cases for chart source components [thumbnail\|upright 1.5](/wiki-images/4/45/Chartsource_basic.png) Page **Basic'' demonstrates that the same chartsource can be attached to several series and be used in several charts. In this example data are provided by means of a `TListChartSource` and a `TRandomChartSource`.\
179	173		[thumbnail\|upright 1.5](/wiki-images/b/b5/Chartsource_statistics.png) PageStatisticsillustrates some applications of the `TCalculatedChartSoruce`: cumulative sums and moving average\
180	174		[thumbnail\|upright 1.5](/wiki-images/4/4e/Chartsource_derivative.png) PageDerivativehighlights numerical calculation and plotting of derivatives of data series using the `TCalculatedChartSource`.\
181	175		[thumbnail\|upright 1.5](/wiki-images/4/4d/Chartsource_sorting.png) Page**Sorting''' shows how the data values of a `TUserDefinedChartSource` can be sorted by means of a `TSortedChartSource` having it as `Origin`. This is an interesting application for a `TBubbleSeries`: when the data points are sorted by radius (y value with y index 1) in descending order the bubble are drawn from back to front. Therefore, it is not possible that bubbles are completely covered by anothers.\
182	176
183	177		### clone
184	178
185	179		<img src="clonedemo-series.png" title="clonedemo-series.png" height="200" alt="clonedemo-series.png" /> <img src="clonedemo-charts.png" title="clonedemo-charts.png" height="200" alt="clonedemo-charts.png" />\
186	180		Page Series of the "clonedemo" demonstrates how a series can be duplicated ("cloned"):
187	181
188	182		``` pascal
189	183		bs := TBarSeries.Create(Self);
190	184		bs.Assign(ChartSeries.Series[i]);
191	185		bs.BarOffsetPercent := bs.BarOffsetPercent + 20;
192	186		ChartSeries.AddSeries(bs);
193	187		```
194	188
195	189		Cloning of a chart, on page Charts, is even simpler:
196	190
197	191		``` pascal
198	192		ch := Chart1.Clone;
199	193		```
200	194
201		-	\
202		-
203	195		### combobox
204	196
205	197		[thumbnail\|upright 1.5](/wiki-images/7/7b/Combodemo.png) Application of the `TChartCombobox` is demonstrated by project "combodemo". It contains a chart with a line, bar and area series and has a sidebar for editing the appearance of these series. Brush and pen styles, pen widths and line series pointer styles can be changed by using this decicated multi-featured combobox. The standard `TColorBox` is used for modifying colors.\
206	198
207	199		### distance
208	200
209	201		[thumbnail\|upright 1.5](/wiki-images/1/1b/Distancedemo-main.png) The [[TAChart documentation\|TDataPointDistanceTool]] was designed to measure the distance of data points in a chart. The `distancedemo` demonstrates is application.
210	202
211	203		Page Main allows to play with the main parameters of the tool. Use the left button to drag a measurement bar across the screen. The mouse-down event determines the starting point, while during dragging the end point is defined by the current mouse position. The distance is displayed in a label above the measurement line. The label can be turned off by setting the tool's `Marks.Visible` to `false`. Rotation of the label along with the measurement bar is controlled by some of the tool's `Options`. The properties `DataPointModeStart` and `DataPointModeEnd` determine whether the measurements starts or ends, respectively, at arbitrary points in the chart (`dpmFree`), or only at data points (`dpmSnap` or `dpmLock`, where `dpmLock` means that the measurement line is only visible when the mouse is near data points, in case of `dpmSnap` it is always visible but jumps to the next data point when the mouse gets close enough).
212	204
213		-	Press the <span class="kbd">SHIFT</span> key while the left mouse button is down to zoom into the chart by a given factor; zoom returns when <span class="kbd">SHIFT</span> is released (code in `TForm1.ctDistance1BeforeKeyDown`).
	205	+	Press the `SHIFT` key while the left mouse button is down to zoom into the chart by a given factor; zoom returns when `SHIFT` is released (code in `TForm1.ctDistance1BeforeKeyDown`).
214	206
215		-	\
216	207		[thumbnail\|upright 1.5](/wiki-images/1/1e/Distancedemo-fit.png) Page Fit shows a more advanced application of the distance tool. It uses its `OnGetDistanceText` event to fit a polynomial to the data between the start and end points of the measurement line. Fitting is done by means of a `TFitSeries`. The radiobuttons at the top ("Mean", "slope", "find peak") determine the degree of the fitted polynomial (0, 2, or 2, respectively). The fitted curved is drawn between the end points of the measurement line. For the code, see `TForm1.ctFitDataPointDistanceTool1GetDistanceText`.
217	208
218	209		This kind of measurement is initiated by dragging with the right mouse button, while the left-drag controls a standard zooming process.
219	210
220	211		(Note that this part of the demo is not working properly in Lazarus 1.2).
221	212
222		-	\
223		-
224	213		### events
225	214
226	215		[thumbnail\|upright 1.5](/wiki-images/3/31/Eventsdemo.png) TAChart exposes several events to control the appearence of the chart beyond the properties provided in the object inspector. The project `eventdemo` shows the effect of three typical events:
227	216
228	217		- `TChart.OnBeforeDrawBackground` is called before painting the entire background rectangle of the chart. The demo shows how the background can be drawn as a gradient.
229	218		- `TChart.OnBeforeDrawBackWall` is a possibilty to replace painting of the backwall of the chart by a user-provided procedure (the "backwall" is the rectangle enclosed by the chart axes). Here, the backwall is drawn as another gradient.
230	219		- `BarSeries.OnBeforeDrawBar` allows to intercept the drawing process of a bar series. In the demo every other bar is drawn in a different fill style.
231	220
232	221		All events provide a parameter `ADoDefaultDrawing` to skip the built-in drawing procedure if set to `false`. In the BarSeries example the 5th bar is dropped by this way.\
233	222
234	223		### extent
235	224
236	225		[thumbnail\|upright 1.5](/wiki-images/b/b6/Extentdemo.png) The project `extentdemo` shows how the extent of a chart, i.e. the start and end of each axis, can be modified (properties `Chart.Extent.XMin`, `Chart.Extent.UseXMin`, etc.).
237	226
238	227		In addition the demo provides code how to setup an extent history which is interesting for undoing extent changes by zooming and panning (see tutorial on "[[TAChart Tutorial: ColorMapSeries, Zooming\|ColorMapSeries, zooming]]").\
239	228
240	229		### fit
241	230
242	231		[thumbnail\|upright 1.5](/wiki-images/1/1f/Fitdemo.png) Basic fitting of equations to data by means of `TFitSeries` is illustrated by project `fitdemo`. The demo shows
243	232
244	233		- how to select the fitting function and the number of fitting parameters (`TFitSeries.FitEquation`, `TFitSeries.ParamCount`).
245	234		- how to restrict the data range for fitting (`TFitSeries.FitRange`)
246	235		- how to extract the values of the fitted parameters (`TFitSeries.Param[]`)
247	236
248	237		In addition, the usage of logarithmic x and/or y axes is demonstrated.
249	238
250	239		> Note: These topics are explained in some detail in the tutorial on [[TAChart Tutorial: ListChartSource, Logarithmic Axis, Fitting\|ListChartSource, logarithmic axis and fitting]].
251	240
252		-	\
253		-
254	241		### func
255	242
256	243		[thumbnail\|upright 1.5](/wiki-images/5/5a/Funcdemo-domain.png) The project `funcdemo` gives examples of the usage of function series.
257	244
258	245		The first page of this multi-tab project, Domain, demonstrates the [[TAChart documentation\|TFuncSeries]]. This series plots a mathematical function. The function values are passed to the series by means of an event handler for `OnCalculate`. This series type has the advantage that the plot is always smooth independent of zooming. The function `y=1/sin(x)` drawn in the screenshot at the right is not defined for integer multiples of `pi`. Therefore, standard output draws vertical connection lines at these points. This artefact can be avoided by adding the points with undefined function values to the `DomainExclusions` of the series. Click at "Domain" to see this effect.\
259	246		[thumbnail\|upright 1.5](/wiki-images/b/b6/Funcdemo-colormap.png) The [[TAChart documentation\|TColorMapSeries]] shown on page Color map is similar to `TFuncSeries`, however, it requires an x and y value to calculate the function value z which is encoded as a color. The calculation is done again in the event handler for `OnCalculate`. The colors are assigned to the z values by means of a ListChartSource which is assigned to the `ColorSource` property of the series.
260	247
261	248		> Note: The tutorial [[TAChart Tutorial: ColorMapSeries, Zooming\|ColorMapSeries, Zoomin]] explains in detail how the ColorMapSeries is applied.
262	249
263		-	\
264	250		[thumbnail\|upright 1.5](/wiki-images/0/0c/Funcdemo-parametric.png) Page Parametric shows another function series requiring an `OnCalculate` event handler, the `TParametricCurveSeries`. Here, a single parameter (`t`) is used to calculate the `x` and `y` values. The example shows the parametric function defined by\
265	251		`x(t) = cos(at) - cos(bt)^j`\
266	252		`y(t) = sin(ct) - sin(dd)^k`.\
267	253		[thumbnail\|upright 1.5](/wiki-images/4/4b/Funcdemo-spline.png) The [[TAChart documentation\|TCubicSplineSeries]] shown on page Spline is similar to a standard `TLineSeries` (black), but the data points are not connected by straight line segments, but by smooth cubic [spline](http://en.wikipedia.org/wiki/Spline_%28mathematics%29) curves (bright blue). The [[TAChart documentation\|TBSplineSeries]] (green) is similar, but the spline does not pass through the data points and, therefore, achieves even better smoothing.\
268	254		[thumbnail\|upright 1.5](/wiki-images/6/6d/Funcdemo-autoyextent.png) Page Auto y extent gives a solution to the problem that it is normally not possible to automatically adjust the y axis to the extent of data values. `TFuncSeries` was equipped with a property `ExtentAutoY` which has to be enabled for this purpose.\
269	255
270	256		### html
271	257
272	258		[thumbnail\|upright 1.5](/wiki-images/5/50/Html_demo.png) Embedding of html tags and entities in TAChart text elements is demonstrated by the project `html`. This feature is activated by setting the `TextFormat` of the corresponding text element to `tfHTML`. The codes used can be show by checking the corresponding checkboxes; the title of the x axis, for example, is written as `'Angle α, °`'.
273	259
274	260		The buttons "Copy to clipboard", "Save to WMF" and "Save to SVG" demonstrate that this special formatting is retained when copying a chart to the clipboard or when saving it to a graphics file.
275	261
276		-	\
277		-
278	262		### legend
279	263
280	264		[thumbnail\|upright 1.5](/wiki-images/3/35/Legenddemo-page1.png%E2%80%8E) The project `legenddemo` demonstrates how the legend of the TChart component can be used and modified. (Please note that after Lazarus version 1.2 the project window contains two pages; in older versions, only the first page is available).
281	265
282	266		Page Basic demonstrates fundamental work with the legend:
283	267
284	268		- showing series names (`series.Legend.Multiplicity = lmSingle`)
285	269		- showing series data (`series.Legend.Multiplicity = lmPoint`, demonstrated for the pie series)
286	270		- owner-drawing series icons for the legend by means of the event `OnDrawLegend` of a series (see `procedure Chart1FuncSeries1DrawLegend`)
287	271		- using legend group titles (`Chart.Legend.GroupTitles`)
288	272		- manually adding legend items (event `series.Legend.OnCreate`, demonstrated for `Chart1FuncSeries1`). Note the workaround for a bug in `FormCreate`.
289	273		- run-time modification of properties for positioning of the legend.
290	274
291		-	\
292	275		[thumbnail\|upright 1.5](/wiki-images/e/ee/Legenddemo-page2.png%E2%80%8E) The second page (OwnerDraw) explains how the legend can be drawn as a gradient bar. For this purpose an event handler must be written for the chart's event `OnDrawLegend`. The gradient is drawn by calling the following procedure:
293	276
294	277		``` pascal
295	278		procedure DrawGradient(ADrawer: IChartDrawer; ARect: TRect;
296	279		AStartColor, AEndColor: TColor);
297	280		var
298	281		y,h: Integer;
299	282		c: TColor;
300	283		begin
301	284		h := ARect.Bottom - ARect.Top;
302	285		if h <= 0 then exit;
303	286		for y := ARect.Bottom-1 downto ARect.Top do begin
304	287		c := InterpolateRGB(AStartColor, AEndColor, (ARect.Bottom - y) / h);
305	288		ADrawer.SetPenParams(psSolid, c);
306	289		ADrawer.Line(ARect.Left, y, ARect.Right, y);
307	290		end;
308	291		end;
309	292		```
310	293
311		-	\
312		-
313	294		### line
314	295
315	296		[thumbnail\|upright 1.5](/wiki-images/a/a8/Linedemo-fast.png) The `linedemo` illustrates some aspects of line series.
316	297
317	298		Page Fast drawing:
318	299
319	300		- Change the selection of the combobox to switch between different `LineType`s of the series. The screen shot at the right is created with the setting `LineType = ltStepXY`.
320	301		- Create a 3D look by checking the option "3D".
321	302		- Interchange the `x` and `y` axes by checking "Rotated".
322	303		- Quickly add 600,000 data points and measure the time for a refresh.
323	304
324		-	\
325	305		[thumbnail\|upright 1.5](/wiki-images/7/7c/Linedemo-pointers.png)
326	306
327	307		Page Pointers shows a list of all pointers that are available for data point markers. The chart is created by using a lineseries with three data points for each pointer `Style`. The name of the style and a different color have been assigned to the center data point in the AddXY method of the series. The size of the pointers can be changed at runtime.\
328	308		[thumbnail\|upright 1.5](/wiki-images/a/a9/Linedemo-customdrawnpointer.png)
329	309
330	310		Page OnCustomdrawn pointer demonstrates how a bitmap can be used as a data pointer, and how only every n-th pointer can be drawn. This is done by means of the event `OnCustomDrawPointer`.\
331	311		[thumbnail\|upright 1.5](/wiki-images/4/4c/Linedemo-ongetpointerstyle.png)
332	312
333	313		Using the event `OnGetPointerStyle` the pointers of individual data points of a line series can be changed. This is demonstrated on page OnGetPointerStyle..\
334	314		[thumbnail\|upright 1.5](/wiki-images/d/d3/Linedemo-oscilloscope.png)
335	315
336	316		Page Oscilloscope: Driven by a timer, more and more data points are added to the line series. The oldest data point is deleted once the series contains more than 20 points. The series is updated continously and is drawn using `LineType=ltStepXY`. The `OnTimer` event handler of the timer contains code to allow zooming into various parts of the chart while preserving the "oscilloscope" behavior.\
337	317		[thumbnail\|upright 1.5](/wiki-images/9/92/Linedemo-coloreach.png)
338	318
339	319		Page Color each data point applies the lineseries property `ColorEach` for colorizing individual datapoints and/or the adjacent line segments. The color is passed as the 4th parameter of the series method `AddXY(x, y, text, color)`.\
340	320
341	321		### listbox
342	322
343	323		[thumbnail\|upright 1.5](/wiki-images/4/4a/Listboxdemo.png) `TChartListbox` is a useful add-on to TAChart for interactively turning selected series on and off. Just add a `TChartListbox` to the form and link its `Chart` property to the chart of interest. The project `listboxdemo` demonstrates that there is a two-way communication between chart and listbox: when listbox items are checked/unchecked the corresponding series are shown/hidden. Conversely, when series are added/deleted/shown/hidden in the chart the changes are reflected in the listbox automatically.\
344	324
345	325		### liveview, liveview-paned
346	326
347	327		[thumb\|upright 1.0](/wiki-images/7/7e/Liveview.png) [thumb\|upright 1.0](/wiki-images/9/91/Liveview-paned.png) These two projects demonstrate usage of the `TChartLiveView` component which displays, in a scrolling viewport, only the most recent data points arriving from some external source.
348	328
349	329		In order to apply a `TChartLiveView` set its `Chart` property to the chart to be controlled. Set `Active` to `true` to activate the live view. Property `ViewportSize` determines the width of the scrolling window in axis units.
350	330
351	331		While the `liveview` project applies to a normal chart with a single y axis, usage of several y axes is demonstrated in the `liveview-paned` project. The creation of a "paned chart" with several axes is the subject of the demo panes.\
352	332
353	333		### multi
354	334
355	335		[thumbnail\|upright 1.5](/wiki-images/9/94/Multidemo-bubble.png) Usage of series with multiple y values is the subject of project `multidemo`. `TListChartSource` provides storage for additional y values in the array `YList[]`.
356	336
357	337		See [[TAChart documentation]] of more details.
358	338
359	339		Page Bubble shows a chart with a [[TAChart documentation\|bubble series]]. This series draws data points as circles of variable radius centered at the data points. In addition to the standard `x`/`y` coordinates there must be a second y value to specify the radius. Since - as usual - a color value can be assigned to a data point bubble charts can show four-dimensional data.\
360	340		[thumbnail\|upright 1.5](/wiki-images/4/48/Multidemo-stacked.png) Page Stacked shows stacked area, bar, or line series charts. Stacked series must provide a y value for the each stack levels. The `TChartStyles` component is used to define the color of the stacks.
361	341
362	342		> Note: A detailed description how to create stacked charts is given in the tutorial [[TAChart Tutorial: Stacked BarSeries\|"Stacked bar series"]].
363	343
364		-	\
365	344		[thumbnail\|upright 1.5](/wiki-images/7/76/Multidemo-boxwhisker.png) A chart with a [[TAChart documentation\|Box-and-Whiskers-Series]] is displayed in page Box-and-Whiskers. This series type represents data as rectangles ("box") with a medium line and two T-shaped protrusions in both directions ("whiskers") . It requires five y values:
366	345
367	346		- Lower whisker
368	347		- Lower box edge
369	348		- Medium line
370	349		- Upper box edge
371	350		- Upper whisker
372	351
373		-	\
374	352		[thumbnail\|upright 1.5](/wiki-images/2/29/Multidemo-ohlc.png) Page OHLC shows a chart with a [[TAChart documentation\|Open-high-low-close series]] which represents data as a vertical lines with two ticks and requires four y values:
375	353
376	354		- Lower point of line = "Low" value
377	355		- Left-facing tick position = "Open" value
378	356		- Right-facing tick position = "Close" value
379	357		- Upper point of line = "High" value
380	358
381		-	\
382	359		[thumbnail\|upright 1.5](/wiki-images/9/96/Multidemo-field.png) A simple [[TAChart documentation\|field plot]] is demonstrated on page Field. This series type draws short arrows at the data points to highlight the directions of a vector field. It requires two x and two y values per data point.\
383	360
384	361		### nan
385	362
386	363		[thumbnail\|upright 1.5](/wiki-images/e/e5/Nandemo.png) The project `nandemo` shows how values can be skipped from a series. Click on an x value in the checklistbox at the right to replace the x or y value of the corresponding data point by NaN. In a line series, a NaN value introduces a break in the originally continuous curve. In other series types, the effect is similar. See [[TAChart documentation]] of more details.\
387	364
388	365		### navigate
389	366
390	367		[thumbnail\|upright 1.5](/wiki-images/0/0b/Navigatedemo.png) For navigation in a zoomed chart, TAChart provides the components [[TAChart documentation\|TChartNavScrollbar]] and [[TAChart documentation\|TChartNavPanel]]. Usage of these components is demonstarted in the `navigatedemo` project.
391	368
392	369		The chart in which the navigation occurs must be assigned to this corresponding property. Note the property `MiniMap` which displays a reduced view of the chart and draws the current viewport as a highlighted rectangle.\
393	370
394	371		### nogui
395	372
396	373		[thumbnail\|upright 1.5](/wiki-images/c/c2/Noguidemo.png) `noguidemo` demonstrates that TAChart can also be used for creating graphics output from console (no-gui) programs. This project creates a chart and a simple bar series at runtime and stores the output to a png file without a user-interface showing up.
397	374
398	375		Note that, for Windows, the `freetype-6.dll` and `zlib1.dll` are required in the exe folder in order to run the demo.\
399	376
400	377		### opengl
401	378
402	379		[thumbnail\|upright 1.5](/wiki-images/a/ac/Opengldemo.png) `opengldemo` presents code how to use OpenGL for improved rendering quality of the chart by means of `TOpenGLDrawer`. See [[TAChart documentation]] for details on this drawer. In addition, the demo illustrates also the usage of [[TAChart documentation\|series transparency]].
403	380
404	381		Note that the package `LazOpenGLContext` needs to be installed to compile this demo.\
405	382
406	383		### panes
407	384
408	385		[thumbnail\|upright 1.5](/wiki-images/d/df/Panesdemo.png) When working with multiple charts in the same window it sometimes required to use common axes. The `panes` demo projects shows two possibilities how to achieve this:
409	386
410	387		In page Link there are three charts, each with one series. The axes of the charts are linked by means of a `TChartExtentLink` component. The axes to be coupled are specified by the `Mode` property. Zoom in one of the chart by dragging a zoom rectangle with the left mouse button, and the other charts will follow.
411	388
412	389		In page Transform there is only one chart, but with three series. Each series covers a third of the vertical chart area with its individual y axis. This effect can be achieved by means of three vertical axes and three [[TAChart documentation\|AutoScaleAxisTransforms]].
413	390
414	391		> Note: Step-by-step instructions are given in the tutorial "[[TAChart Tutorial: Multiple Panes in one Chart\|Multiple panes in the same chart]]".
415	392
416		-	\
417		-
418	393		### print
419	394
420	395		[thumbnail\|upright 1.5](/wiki-images/f/f8/Printdemo.png) `printdemo` illustrates two ways of printing charts:
421	396
422	397		- using direct painting on the printer's canvas by clicking on button "Print via canvas",
423	398
424	399		``` pascal
425	400		Chart1.PaintOnCanvas(Printer.Canvas, ARect)
426	401		```
427	402
428	403		- or using a dedicated drawer for printing (by clicking on button "Print") which generally yields better quality. Package `TAChartPrint` is necessary to use `TPrinterDrawer`. See [[TAChart documentation]] for details on [[TAChart documentation\|TPrinterDrawer]].
429	404
430	405		``` pascal
431	406		Chart1.Draw(TPrinterDrawer.Create(Printer), ARect);
432	407		```
433	408
434	409		In general, printer support requires the package `Printer4Lazarus`. The demo also shows how axis marks can be highlighted by a border (`Chart1.LeftAxis.Marks.Frame.Visible := true`).\
435	410
436	411		### radial
437	412
438	413		[thumbnail\|upright 1.5](/wiki-images/8/86/Radialdemo_pie.png) The `radialdemo` project introduces two series, the [[TAChart documentation\|TPieSeries]] and the [[TAChart documentation\|TPolarSeries]]. Both interpret the x/y coordinates as angle and distance from center, but in an opposite way.
439	414
440	415		`TPieSeries` shown on page Pie assumes that the y value of the chart source is the angle of the pie, and the x coordinate corresponds to the distance of the slice from the center. Therefore, the effect of the "exploded" slice can be achieved by increasing the x value (if property `Exploded` is set). In addition, the demo allows to play with some properties of the pie series:
441	416
442	417		- `MarkPositions`
443	418		- `RotateLabels`
444	419		- `Marks.LabelFont.Rotation`
445	420
446	421		See section [[TAChart documentation\|Pie series]] in the [[TAChart documentation\|documentation]].\
447	422		[thumbnail\|upright 1.5](/wiki-images/a/a7/Radialdemo_polar.png) The second page Polar shows two polar series. In a polar series, the x value is interpreted as the angle in radians, and the y value corresponds to the distance of the point from the center.
448	423
449	424		Both series are linked to the same ChartSource. They are offset with respect to each other because the properties `OriginX` and `OriginY` are different. The checkbox "Closed" allows to close the polygons (property `CloseCircle`) by connecting the first data point with the last one.
450	425
451	426		See section [[TAChart documentation\|Polar series]] in the [[TAChart documentation\|documentation]].\
452	427
453	428		### rotate
454	429
455	430		[thumbnail\|upright 1.5](/wiki-images/c/cc/Rotatedemo.png) "Rotate" in the context of project `rotatedemo` means "rotation of a series with respect to the x and y axes", i.e. painting of a series with x and y axes interchanged.
456	431
457	432		The demo starts with a line series, a bar series and a 3d area series in the regular arrangement of x along the horizontal and y along the vertical axis. After checking the checkbox assigned to a series, its x values are drawn along the vertical and the y values along the horizontal axes. In the rotated configuration the bars of a bar series are drawn horizontally.
458	433
459	434		In TAChart, this kind of rotation is achieved by assigning the property `AxisIndexX` to the index of the vertical axis, and `AxisIndexY` to that of the horizontal axis.
460	435
461	436		In addition to rotation, the demo project allows also to play with the position of the series marks by changing the property `MarkPositions` of the red dotted line series.\
462	437
463	438		### save
464	439
465	440		[thumbnail\|upright 1.5](/wiki-images/d/da/Savedemo.png) The project `savedemo` shows code how to save a chart to an external graphics file (.bmp, .png, .jpg, .svg)
466	441
467	442		``` pascal
468	443		Chart1.SaveToBitmapFile('test.bmp');
469	444		```
470	445
471	446		or to copy it to the clipboard
472	447
473	448		``` pascal
474	449		Chart1.CopyToClipboardBitmap;
475	450		```
476	451
477		-	\
478		-
479	452		### script
480	453
481	454		[thumbnail\|upright 1.5](/wiki-images/f/f3/Scriptdemo.png) The project `scriptdemo` applies [[Pascal Script\|PascalScript]] to define the mathematical function shown in a [[TAChart documentation\|TFuncSeries]]. In this way a mathematical function plotter can be created.
482	455
483	456		A tutorial on usage of TFuncSeries can be found [[TAChart Tutorial: Function Series\|here]].\
484	457
485	458		### tools
486	459
487	460		[thumbnail\|upright 1.5](/wiki-images/e/ea/Toolsdemo.png) Project `toolsdemo` gives the opportunity to play with TAChart's zooming and panning tools. Follow the instructions on the screen to activate the individual tools.
488	461
489	462		Internally, the work is done by the `TChartTool` components. Have a look at chapter [[TAChart documentation\|Tools]] in the [[TAChart documentation]] or the tutorial "[[TAChart Tutorial: Chart Tools\|Chart tools]]" to learn details on this powerful add-on to TAChart.\
490	463
491	464		### wmf
492	465
493	466		[thumbnail\|upright 1.5](/wiki-images/b/bc/Wmfdemo.png) `wmfdemo` saves a chart to a windows metafile (.wmf):
494	467
495	468		``` pascal
496	469		with Chart1 do
497	470		Draw(TWindowsMetafileDrawer.Create('test.wmf'), Rect(0, 0, Width, Height));
498	471
499	472		// or, after r46404:
500	473		Chart1.SaveToWMF('test.wmf');
501	474		```
502	475
503	476		Since r46396, a chart can be copied to the clipboard as a windows metafile (windows-only); use an empty file name string in above `Draw` code for this purpose. After r46404, the simpler `Chart1.CopyToClipboardMetafile` has the same effect.
504	477
505	478		> Note: wmf support in TAChart is very limited. In particular, it is available only on the Windows platform. Package `TAChartWMF` is required to compile this demo.
506		-
507		-	\
508	479
509	480		## Related documents
510	481
511	482		Main documentation:
512	483
513	484		- [[TAChart documentation]]
514	485
515	486		Tutorials:
516	487
517	488		- [[TAChart Tutorial: Getting started\|Getting started]]
518	489		- [[TAChart Tutorial: BarSeries\|Bar series]]
519	490		- [[TAChart Tutorial: Stacked BarSeries\|Stacked bar series]]
520	491		- [[TAChart Tutorial: ListChartSource, Logarithmic Axis, Fitting\|ListChartSource, logarithmic axis, fitting]]
521	492		- [[TAChart Tutorial: Userdefined ChartSource\|User-defined ChartSource]]
522	493		- [[TAChart Tutorial: Dual y axis, Legend\|Dual y axis, legend]]
523	494		- [[TAChart Tutorial: Chart Tools\|Chart tools]]
524	495		- [[TAChart Tutorial: Function Series\|Function series]]
525	496		- [[TAChart Tutorial: ColorMapSeries, Zooming\|ColorMapSeries, zooming]]
526	497		- [[TAChart Tutorial: Multiple Panes in one Chart\|Multiple panes in the same chart]]
527	498		- [[TAChart Tutorial: Background design\|Background design]]
528	499		- [[BGRABitmap tutorial TAChart]]
529	500
530	501		---
531	502		From the Free Pascal wiki, page "TAChart Demos", as it stood on 2021-08-09 after a change by Wp, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).
532	503		Category: Components
533	504		Category: Lazarus
534	505		Category: TAChart

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