Is it possible to use histc in for-loop?

Hi all I am currently having some problems doing some tests for research. The general idea is having an array of X and Y values : X=[-3;-1;0;1;3] and Y=[0;0.3;0.5;0.7;1]. A 1000 times for-loop has to generate values of Y with rand(1) function and interpolate corresponding values of X from the arrays above. And a count has to be initiated to calculate what values fall in the interval X_int=linspace(-3,3) (which has 100 intervals). My suggestion is :

if true
  % code
end
x=[-3;-1;1;3]; y=[0;0.3;0.5;0.7;1];
bin_ranges=linspace(-3,3);
for i=1:1000
  yq_r=rand(1);
  xq=interp1(y,x,yq_r,'linear','extrap');
  bin_counts=histc(xq,bin_ranges)
end

Is it possible to use the histc function in this for-loop, because when I run it, it records only one value of increment (only one 1) in the bin_counts array and not 1000 different? Thank you in advance !

Answer 1

[Image Analyst]

You're only interpolating one value so xq will have only one bin with anything in it. Plus, for each iteration, you're just overwriting bin_counts, not adding to it. Maybe you want

bin_counts = bin_counts + histc(xq,bin_ranges);

though that's still an incredibly inefficient way of doing it instead of just creating the vector completely and then calling histc on the whole thing after you're done building it.

[Markian Petkov]

How am I meant to create this vector (you mean vector of values of xq, right). I thought the same, but I couldn't actually realised how to do it... :? Thanks

[Image Analyst]

You can pass in an array as the third argument to interp1. Get rid of the loop in that case - the case where you pass in rand(1,1000) instead of yq_r.