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Cannot draw circle with XYchart |
Posted by Michele on Apr-23-2022 21:58 |
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Hello,
I am using OSX 12.2 and ChartDirector 7. I created an XYchart in a C++ code with
XYChart *chart;
chart = new XYChart(width_chart, height_chart);
and then plotted a set of scattered data in the chart. So far, everything works. Now I would like to draw an spline with addSplineLayer (https://www.advsofteng.com/doc/cdpydoc/XYChart.addSplineLayer.htm).
However, the first argument of addSplineLayer is said to be 'An array of numbers representing the data set'. Instead of an array of numbers, I would need to enter an array of pairs of numbers, where each pair (x,y) is the given by abscissa and ordinate of the n-th point through which the spline will pass.
How may I plot an spline given an array of pairs (x,y) ?
Thank you for your help |
Re: Cannot draw circle with XYchart |
Posted by Michele on Apr-24-2022 00:30 |
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I am sorry, this post has obviously the wrong title |
Re: Cannot draw circle with XYchart |
Posted by Peter Kwan on Apr-24-2022 17:42 |
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Hi Michele,
You can plot a spline layer (or any other XY layers in ChartDirector) by provide an array for the x-coordinates and an array for the y coordinates. It is like:
SplineLayer *layer = c->addSplineLayer(DoubleArray(yDataPtr, yDataCount), ....);
layer->setXData(DoubleArray(xDataPtr, xDataCount));
The following is an example. It uses addLineLayer, but the same code works with addSplineLayer too:
https://www.advsofteng.com/doc/cdcpp.htm#xyline.htm
Best Regards
Peter Kwan |
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