MATLAB: Saving values in a for loop

Question

My code looks something like this

 x = -10:0.1:10;
 f1 = trapmf(x,[-2 0 0 2]);
 for k = 0.05:0.05:1
    index = find(abs(f1-k)<10^(-10))
    Xidx = x(index)
 end

I want to save my Xidx to plot x(index) for all k values, but it currently saves only the last iteration

Any solution?

Answer 1

 x = -10:0.1:10;
 f1 = trapmf(x,[-2 0 0 2]);
 kvals = 0.05:0.05:1;
 for kidx = 1 : length(kvals)
    k = kvals(kidx);
    index = find(abs(f1-k)<10^(-10))
    Xidx(kidx) = x(index)
 end