Cartesian to polar sorting

I converted a set of coordinates from Cartesian to polar form

[rho,theta] = cart2pol(x,y);

Next I sorted the polar coordinates

theta_ascend = sort(theta,'ascend');

As in the case of any polar system I will have multiple values of rho for one value of theta. For every value of theta I want to select the maximum value of rho and reject the other values.

for e.g If my values are

theta = 3.14 3.14 3.14 3.13 3.13 3.12 3.12 3.12 . . . rho = 12 15 6 3 5 8 2 11 . . .

I want my output to be theta = 3.14 3.13 3.12 . . . rho = 15 5 11 . . .

Please suggest ?

Answer 1

[Matt Fig]

As an example:

% First some data to work with:
thet = round(rand(1,10)*3)
r = round(rand(1,10)*30)
% Now match the largest r per unique thet:
M = sortrows([thet.',r.']);
M = M([logical(diff(M(:,1)));true],:)

[Suhas Deshpande]

For some reason I am not able to convert the sorted polar coordinates to Cartesian

[x,y] = pol2cart(M(:,1),M(:,2))

or

[x,y] = pol2cart(theta,rho)

gives an error

Error: Unexpected MATLAB operator.