[Back to JKQTPlotter main page](https://github.com/jkriege2/JKQtPlotter/) # JKQtPlotter ## Scatter Graph with Parametrized Symbols/Colors This project (see `./examples/simpletest_paramscatterplot/`) demonstrates the capabilities of `JKQTPxyParametrizedScatterGraph`. This graph class plots symbol&line-graphs, juts like [`JKQTPxyLineGraph`](https://github.com/jkriege2/JKQtPlotter/blob/master/examples/simpletest_symbols_and_styles/) and in addition modifies several properties of each plot point by data from an additional column. These properties can be modified: - symbol size - symbol type - symbol/line color - line width The source code of the main application can be found in [`jkqtplotter_simpletest_paramscatterplot.cpp`](https://github.com/jkriege2/JKQtPlotter/blob/master/examples/simpletest_paramscatterplot/jkqtplotter_simpletest_paramscatterplot.cpp). First, several datasets are generated and added to the internal datastore. the resulting datatable looks like this: ![jkqtplotter_simpletest_paramscatterplot](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/jkqtplotter_simpletest_paramscatterplot_datatable.png) Then several plots are added that modify different properties. The simplest case is to modify the symbol type. Simply set the property `symbolColumn` with `graph1->set_symbolColumn(columnP)` to a data column. The values in the data column will be cast to an integer and then will be translated to `JKQTPgraphSymbols`. If the numbers are larger than the available symbol types in `JKQTPgraphSymbols`, the graph will cycle through the available symbols (via a modulo-operation with the max. symbol count!). ```c++ JKQTPxyParametrizedScatterGraph* graph1=new JKQTPxyParametrizedScatterGraph(&plot); graph1->set_xColumn(columnX); graph1->set_yColumn(columnY1); graph1->set_symbolColumn(columnP); graph1->set_drawLine(true); graph1->set_color(QColor("blueviolet")); graph1->set_title("1: symbol type"); plot.addGraph(graph1); ``` The next two code snippets show how to modify the size of the symbols and the line width of the lines, connecting the symbols (ensure to set `graph6->set_drawLine(true)`, because otherwise no line will be drawn). The principle is the same as above, but here you need to set the properties `sizeColumn` for the symbol size and `linewidthColumn` for the line width. All values in the line width or symbol size columns are interpreted as sizes in dtp points (pt)! ```c++ // symbol size JKQTPxyParametrizedScatterGraph* graph3=new JKQTPxyParametrizedScatterGraph(&plot); graph3->set_xColumn(columnX); graph3->set_yColumn(columnY3); graph3->set_sizeColumn(columnS); graph3->set_symbol(JKQTPfilledCircle); graph3->set_drawLine(true); graph3->set_title("3: symbol size"); plot.addGraph(graph3); // line width JKQTPxyParametrizedScatterGraph* graph6=new JKQTPxyParametrizedScatterGraph(&plot); graph6->set_xColumn(columnX); graph6->set_yColumn(columnY6); graph6->set_linewidthColumn(columnLW); graph6->set_drawLine(true); graph6->set_symbol(JKQTPnoSymbol); graph6->set_title("6: line width"); plot.addGraph(graph6); ``` Finally you can set the color of each symbol, based on data in the column `colorColumn`. Here two possibilities exist: First you can store the RGB(A) value for each datapoint explicitly. For this, you first need to create the data in the column, using the Qt-function [`qRgb()`](http://doc.qt.io/qt-5/qcolor.html#qRgb) or [`qRgba()`}(http://doc.qt.io/qt-5/qcolor.html#qRgba): ```c++ QVector RGB; const int Ndata=10; // number of plot points in each curve for (int i=0; iaddCopiedColumn(RGB, "rgb"); ```c++ Basically the data points in a RGB(A)-column will be interpreted by castig them to [`QRgb`](http://doc.qt.io/qt-5/qcolor.html#QRgb-typedef). Now you can add the graph. In order to interpret the color column as RGB(A)-values, ensure to set `graph4->set_colorColumnContainsRGB(true)`: ```c++ JKQTPxyParametrizedScatterGraph* graph4=new JKQTPxyParametrizedScatterGraph(&plot); graph4->set_xColumn(columnX); graph4->set_yColumn(columnY4); graph4->set_colorColumn(columnRGB); graph4->set_colorColumnContainsRGB(true); graph4->set_drawLine(true); graph4->set_symbol(JKQTPfilledDownTriangle); graph4->set_title("4: RGB-color"); plot.addGraph(graph4); ``` The second variant for setting the color of each datapoint is by mapping the values in the column to a color palette (`JKQTPMathImageRYGB` in this example). For this you simply need to define the color coumn and the palette to use. By default, the color palette spans the full range of values in `colorColumn`: ```c++ JKQTPxyParametrizedScatterGraph* graph2=new JKQTPxyParametrizedScatterGraph(&plot); graph2->set_xColumn(columnX); graph2->set_yColumn(columnY2); graph2->set_colorColumn(columnC); graph2->set_palette(JKQTPMathImageRYGB); graph2->set_symbol(JKQTPfilledRect); graph2->set_drawLine(true); graph2->set_title("2: color"); graph2->get_colorBarRightAxis()->set_axisLabel("color scale for graph2"); plot.addGraph(graph2); ``` Note: If you want to set the range manually, use `ste_imageMin()` and `set_imageMax()` after setting `set_autoImageRange(false)`. Note also that it is possible to combine any of parametrizations above in a single graph, by setting two or more columns: ```c++ JKQTPxyParametrizedScatterGraph* graph5=new JKQTPxyParametrizedScatterGraph(&plot); graph5->set_xColumn(columnX); graph5->set_yColumn(columnY5); graph5->set_colorColumn(columnC); graph5->set_sizeColumn(columnS); graph5->set_palette(JKQTPMathImageBLUEYELLOW); graph5->set_drawLine(true); graph5->set_title("5: color+size"); graph5->get_colorBarRightAxis()->set_axisLabel("color scale for graph5"); plot.addGraph(graph5); ``` The full test appication combines all these variants and the result looks like this: ![jkqtplotter_simpletest_paramscatterplot](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/jkqtplotter_simpletest_paramscatterplot.png) [Back to JKQTPlotter main page](https://github.com/jkriege2/JKQtPlotter/)