How to calculate mean and SD of Z coordinates within a circle I drew out of a figure?

Hi

I asked the same question a month ago, but I think I didn’t clearly explain what I wanted to know.

I took a full-sky image with a fish-eye lens and played with pixels to produce a figure shown as below. I’d like to calculate the mean and SD inside a circle I randomly drew. Each point of the figure contains (x, y, z) coordinates. Z value is the result of some calculations I did with the original pixel values. I color-mapped the figure with colorcube. It can be color-mapped with copper, autumn, bone, whatever… What I want to say is that the color of a certain coordinate may change but its Z value does not. I want to calculate the mean and SD of the Z values of the coordinates inside the circle.

Could anyone help me with this? Thank you in advance!!

Answer 1

[KSSV]

Read about inpolygon. You have circle coordinates and image coordintes. Use inpolygon and get the coordinates lying inside the circle. YOu will gt (x,y,z) points lying inside the circle and then you can use mean and std.