# Easy tool for polar graph plotting

I have a test case, where I am mapping the various trigger point for a motion sensor. Now I have various points on a 10 degree resolution, need to plot it in a polar graph on something like following image.

Please recommend an online tool or software where I can plot something like this.

I suggest taking a look at the Plot.ly tool chain, e.g. https://plot.ly/python/polar-chart/

There are Plotly libraries available as free & open source for:

• R
• JavaScript
• Python which I would recommend
• Pandas
• Node.JS
• Matlab

I see a point at about 50 degrees azimuth and at a distance of about 12. That data plots the point but the point can also be plotted by x and y coordinates.

x-coordinate or East coordinate = Sin(Azimuth) * Distance

y-coordinate or North coordinate = Cos(Azimuth) * Distance

If a software is needed that plots by azimuth and distance then Scratch-Plot by KBH Applications will do that. The graph itself can be plotted separately from the data and copied and pasted from one Scratch-Plot file to another. A first point input into Scratch-Plot of a N,E of -15,-15 and a second point input of a N,E of 15,15 will configure to put the N,E 0,0 point at the center of the screen. Then input the N,E of 0,0 , click "Az", and begin plotting by azimuth and distance. Also, click "Fan" to plot all points from the same beginning point. Now the 360 degree azimuth will be set vertical on the screen. Well, the azimuth inputs could have a constant of 10 added to them (as a rotation) for the required orientation but they would labeled without the constant added.

Also, a Scratch-Plot file can be opened with a text editor and contains both user coordinates and screen coordinates.

Or the above x and y coordinates can be converted to screen coordinates and plotted in MS Paint. A beginning positive y-coordinate becomes negative while a beginning negative y-coordinate becomes positive. Furthermore, a zero y-coordinate needs a constant added (a coordinate translation) to it so that the zero y-coordinate moves the center of the screen. Then all the y-coordinates must have that same constant added to them. Next the zero x-coordinate needs a constant added to it so that the zero x-coordinate moves to the center of the screen. Or course all the x-coordinates must have that same constant added to them. Finally, the x-coordinates must be multiplied by a constant (as coordinate scaling) so that the x-coordinates plot at the same scale as the y-coordinates.

• Please post a polar graph image generated by Scratch-Plot, thanks! Feb 14, 2019 at 5:19