Extracting the theta and r data of a polar plot using the WebPlotDigitizer and replotting in MATLAB
In this short video, I briefly explain how to extract the raw data of a polar plot using the WebPlotDigitizer and and to save it as a text file of comma-separarated values. For this, a Microsoft Visio file of the plot is converted into a PDF file, which is then imported into the WebPlotDigitizer. After calibrating the polar axes and selecting the main color of the graph, the data can be automatically extracted. In MATLAB, the zero point of the polar axes and the direction of the theta axis have to changed to make the new reproduced graph similar to the original one.
WebPlotDigitizer:
https://automeris.io/wpd/
MATLAB commands:
rawdata=load('polar_plot.csv');
rawdata(1:10,:)
rawdata=rawdata(:,[2 1]);
rawdata(1:10,:)
rawdata=sortrows(rawdata);
rawdata(1:10,:)
theta=rawdata(:,1);
r=rawdata(:,2);
figure(1)
ax=polaraxes;
polarplot(ax,theta,r);
polarplot(ax,theta/180*pi,r);
ax.ThetaZeroLocation='top';
ax.ThetaDir='clockwise';
Chapter marks:
00:00 Introduction