How to get first value of an array with condition

I need to get the first value of a matrix (x2 below) that I initially put condition to, for example:

    x1 = Data{i}.Error(something == 1, 1)
    x2 = x1(1)

I need to do this within one step without creating `x1', is it possible? Obviously

Data{i}.Error(something == 1, 1)(1)

won't work

[Brian Katz]

How would you do the same thing with a table construct?

Scenario{4}(Scenario{4}.sID==35,{'Groupe'})

[Adam Danz]

Assuming Groupe is a table variable, and Scenario{4} is a table,

Scenario{4}(Scenatrio{4}.Groupe(Scenario{4}.sID==35))

not tested

Answer 1

[Adam Danz]

By using the 2nd input to find() you can get just the first index of 'Error'.

% fake data
Data{1}.Error = magic(10); 
something = [0 1 0 1 0 1 0 0 0 0]; 

% 2-line method
x1 = Data{1}.Error(something == 1, 1); 
x2 = x1(1);  

% 1-line method
x3 = Data{1}.Error(find(something == 1, 1), 1); 

% Check that they match
x2 == x3

Note that this works if x2 is always the first element of x1. If you're looking for the n_th element of x1 you'll need to replace find() with

max(find(something == 1), n).