Drawing Polar plot

hi dear experts,

I want to draw something like this :

Screenshot from 2021-05-27 06-17-51

I have a 2D histogram that represents radius and angle.

I drew it by using the POL option but it did not work. I think I may define angle interval and draw counter lines by using the cont3 option. if it is correct I don’t know how can I define angle intervals and draw counter as a function of radius and angle.

how can I do this?

I attach my .root file, there is a 2d histogram in which 0-48 represents 48 angle intervals (3.75 degrees) and 0-24 represents radiuses.

result.root (5.2 KB)

many thanks,
Keyvan

There is no simple option producing such plot (half circle) with contour plots from a TH2…
The Pol option is one way to represent polar plots. Also there is TGraphPolar. But none of them will produce such plot.

hi couet thank you for your reply,

the picture that I sent, shows a half-circle plot because of its data, dawing half-circle is not critical, It can be a circle with data that are in a half-circle.

what is important is drawing a counter-polar plot.

like this :

Draw(“LEGO2 POL”) gives me:

I am not sure that’s what you are looking for.

couet thank you for your reply,

i drew it by Draw(“LEGO2 POL”) but i got this :

why my result and your result is different?

thank you it is almost what i want, for achieving an accurate plot i must multiple each 0-48 degrees intervals by 3.75 for creating angle intervals and create another 2D histogram with new angle intervals and radius.

how can i represent radiuses and angles?, like the second picture that i sent.

radiuses are represented on cerntral axis.

many thanks,

I changed the viewing angles…you can try interactively. Without POL I get: