MATLAB: Mean and standard deviation of a field – condition on another field

Question

Hi. I am working with a structure array S (1 X 50,000) with 10 fields. I want to calculate the mean and standard deviation of field f1 based on a condition on field f2.

For example,

Here is the input,

S(1).f1=[10,20,30 40,50,60] and S(1).f2=[100,20,50,60,70,140];

S(2).f1=[56,98,74,87,99] and S(2).f2=[101,54,69,20,11]

S(3).f1=…… and S(3).f2=…..

S(4).f1=…. and S(4).f2=…..

.

.

S(i).f1=…. and S(i).f2=….

I want to calculate the mean of f1 elements whose corresponding f2 field values are 50 < f2 <=100

Meaning, S(1).f1=[10,40,50] and S(2).f1=[98,74] should be considered in calculation of mean.

I want to calculate several mean values of f1 based on different conditions on f2.

Answer 1

How can I get one single (explicit) mean and standard deviation?

F1=[S.f1];
F2=[S.f2];
F=F1(F2>50 & F2<=100);
MEAN=mean(F);
STD=std(F);