I have a 2D matrix of latitude and longitude coordinates that I have used to create a mask. The mask is comprised of NaNs and 1s, depending on if the grid box is included in my mask.
What I want to do is find the coordinates of the boundary of this mask, so that I can plot a line around the shape designated by the 1s.
NaN NaN NaN NaN NaN
NaN 1 1 NaN 1
NaN 1 1 1 1
NaN NaN NaN 1 NaN
How do I draw a line around the shape seen in the 1s, and save the coordinates of this line so that I can overlay it in other plots?
I've tried using contour, but it gives diagonal lines, where I only want horizontal or vertical lines.
Any help would be greatly appreciated.