constant randperm in each iteration

Question

NA 2019-2-13

评论： Jan 2019-2-14

all=[2;3;4;56;7;89;5;1;5;1;3;6;7;9];
changed=9;
p = randperm(size(all,1));
p(1:changed)=[];
t=all/2
t(p)=0;

I want to run this code 10 times and want to have a same t in each iteration.

I tried to use 'seed' but have error.

NA 2019-2-14

all=[2;3;4;56;7;89;5;1;5;1;3;6;7;9];
changed=9;
p = randperm('seed',size(all,1));
p(1:changed)=[];
t=all/2
t(p)=0;

Error using randperm

Inputs must be nonnegative scalar integers.

Jan 2019-2-14

Please take the time to read the documentation if you have a problem with a command:

doc randperm

You cannot provide a 'seed' for this command. Trying this is pure guessing, and this must fail soon. Only the random number generator can be seeded.

Answer 1

Steven Lord 2019-2-13

First, you should probably use a different variable name for your vector of data. all already has a meaning in MATLAB.

Second, define a fixed variable before whatever loop you're using to iterate then set t to that fixed variable at the start of each iteration.

fixedt = allVector/2;
for iterations = 1:10
    t = fixedt;
    % do stuff with t
end

Jan 2019-2-14

编辑：Jan 2019-2-14

@Naime: Of course. If you want a variable to have the same value for all iterations, define it outside the loop and do not change it inside.