CODEWITHSUNDEEP
matlabrandomintegerrange
KiMaN
KiMaN

Reputation: 319

Matlab: random integers from a range with no repetition

I want to get an array with randomized integer included in range with no repeat, I used :

randperm(15,3)

output is :

8, 10, 12

This function not use a range, I would like to random values only from 10 e.g.

Upvotes: 2

Views: 1688

Answers (1)

SecretAgentMan
SecretAgentMan

Reputation: 2854

If you have the Statistics toolbox, you can use randsample without replacement. 

% MATLAB R2017a
LB = 3;   % lower bound of range (integer)
UB = 17;  % upper bound of range (integer),  UB > LB
randsample(LB:UB,3,'false')

@Wolfie's method using randperm works well and requires no toolbox.

LB - 1 + randperm(UB-LB+1,3)

Notice that randi works well for uniformly distributed (discrete uniform) integers in a range but it samples with replacement (can give duplicates). This requires no toolbox to my knowledge but would require combining with a procedure to remove duplicates and resample until all integers were unique. 

randi([LB UB],3,1)

Note: will remove @Wolfie's method if @Wolfie posts it as answer or can make this answer community wiki based on consensus.

Upvotes: 4

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