MATLAB: Picking random points…

MATLAB

Hi
I am exploring a closed (time) interval between 0 and 1. I have used the linspace command to generate it:
t=linspace(0,1);
I can't seem to figure out how to randomly pick 10 (say) of these points in t so that I can plug them into a function (selected in a non-uniform way). Any thought?
Many thanks
Joe

Best Answer

You can simply generate some indices to pick value from the vector t. I have shown you uniformly distributed random indices, because you did not tell us what random distribution you want. Two solutions are shown below: without and with index repetition.
t = linspace(0,1);
N = 5; % how many points to pick
Without repetitions use randperm:
>> idx = randperm(numel(t),N)
idx =
   45   75   58   51   15
>> t(idx)
ans =
   0.44444   0.74747   0.57576   0.50505   0.14141
With repetitions use randi:
>> idy = randi(numel(t),1,N)
idy =
   53   44   11   77   71
>> t(idy)
ans =
   0.52525   0.43434   0.10101   0.76768   0.70707
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