# SOLVED - Area of all children vs Area Parent

#1

Good morning,
I need to calculate the area of children objects that belong to their parent and I cannot find a way to do that.
I was able to identify my two objects, MeasureSizeAndShape then I made the parent/child relation with RelateObjects correctly. I’m missing something to do the sum of all the “Area” of each child of a parent.

To sum it up:
Parent has an area of 12 and has 3 children (A,B,C)
A has an area of 2
B has an area of 3
C has an area of 4

I want to get to: (2+3+4)/12
Result:9/12

I know I can play around with excel but I’d rather have cellprofiler doing it if possible.

Any suggestion would be appreciated!

Thanks a lot for this great software

#2

Hi,

There are a couple ways to do that, but IMO this is the easiest:

Since you can have RelateObjects calculate the mean child object area, and RelateObjects will also give you the child count, to obtain the sum of the total child areas you could just multiply the two in CalculateMath, then use another CalculateMath module to divide that total by the area of the parent.

#3

Awesome!!!
Elegant solution, thanks a lot!