How to plot the contour polar map in matlab

Dear Mathlab users.

I am geoscience student, studying in University Technology PETRONAS, malaysia.

I need the help to plot the contour polar map,

I have X,Y,Z data

X= Azimuth ( 0 - 360) Theta

Y= Inclination ( 0 - 90) Radius

Z = values (0 - 1) contour line vales,

How can I process with this three data to get the contour polar plot.

I attached the csv input data and result of the plot using origin lab (example but the same as I want from Matlab),

Thank you and I appreciate for considering my problem.

Best Regards,

Hein

[Adam Danz]

Unfortunately HEIN HTET ZAW has removed the content of this question which contained the demo data that made the answer useful to other people.

Copy of question

Dear Mathlab users.

I am geoscience student, studying in University Technology PETRONAS, malaysia.

I need the help to plot the contour polar map,

I have X,Y,Z data

X= Azimuth ( 0 - 360) Theta

Y= Inclination ( 0 - 90) Radius

Z = values (0 - 1) contour line vales,

How can I process with this three data to get the contour polar plot.

I attached the csv input data and result of the plot using origin lab (example but the same as I want from Matlab),

Thank you and I appreciate for considering my problem.

Best Regards,

Hein

[Rena Berman]

(Answers Dev) Restored edit

[Adam Danz]

Thanks Rena. But it looks like it's been deleted again. Since the data is used in my answer, maybe it could be attached to the answer.

Answer 1

[Adam Danz]

Hmmmm, I'm not sure if it's possible to directly draw contour lines in polar coordinates with Matlab (I'd love to know otherwise). But here are some alternatives.

Use a scatter plot on polar coordinates.

polarscatter() allows for 3D inputs

% 'vals' are your values, 'az' azimuth, 'incl' inclination.
valScaled = round(vals*100); 
colmap = colormap(jet(101)); 
figure
ph = polarscatter(az * pi/180, incl, [], colmap(valScaled+1,:), 'filled'); %convert to radians
colormap(colmap)
h = colorbar(); 
ylabel(h, 'value')

Plot contour lines, but in Cartesian coordinates

% az are your azimuth data (column vector)
% incl are your inclination data (column vector)
% vals are your 3rd column of data. 
azMat = reshape(az, length(unique(az)), []);    
inclMat = reshape(incl, [], length(unique(incl))); 
valsMat = reshape(vals, length(unique(az)), length(unique(incl))); 
figure
contour(azMat, inclMat, valsMat)
xlabel('azimuth')
ylabel('inclination')
h = colorbar; 
ylabel(h, 'values')

Use a 3rd party function from the file exchange

There are several. I tried out the file exchange function polarcont() : https://www.mathworks.com/matlabcentral/fileexchange/14826-polar-contour-plot

This transforms the data from polar to cartesian coordinates and plots it in cartesian space.

valsMat = reshape(vals, length(unique(az)), length(unique(incl))); 
figure
polarcont(unique(incl), unique(az * pi/180), valsMat', 20); %note conversion to radian & transpose!

[HEIN HTET ZAW]

Sir Danz,

Is it possible to show the value by contour lines? I want to use contour polar map instead of using coloar map. As I shown the photo is the same as I want but I don't have idea to write script for it.

However, thank you and I appredicated for your helping.

Best Regards,

Hein

[Adam Danz]

I updated my answer to provide 2 more alternatives. If you find the solution you're looking for elsewhere, I'd be happy to see it.

[HEIN HTET ZAW]

Thank you so much for consideration sir Danz, your answer is quite useful for me.