How to generate a random matrix with a constraint or step range ?

9 Ansichten (letzte 30 Tage)
Varun Pai
Varun Pai am 23 Apr. 2020
Kommentiert: Varun Pai am 23 Apr. 2020
I want to generate a Nx4 random matrix. In this matrix, each column is considered having different range and step. The random values should be only from these steps.
For e.g. 1st column 0:0.1:1
2nd column > 0:1:10
3rd column > 2:0.5:8
4th column > 0:-1:-10
I want to generate a random matrix of N=5. I should get a matrix with above conditions. Like this
[0 5 3.5 -5 ;
0.8 8 7 -3
0.2 0 2.5 -7
0.6 8 6.5 0
0.9 3 7.5 -9]
The N value could go to any size. Repeated values are permissible. I tried some random functions like randperm, randsample etc but I am not able to produce like this. Randperm is not allowing to produce repeated values.
How could I generate it ? Could you help with a code sample ?

Akzeptierte Antwort

KSSV
KSSV am 23 Apr. 2020
Bearbeitet: KSSV am 23 Apr. 2020
Read about randsample, randperms.
C1 = 0:0.1:1 ;
C2 = 0:1:10 ;
C3 = 2:0.5:8 ;
C4 = 0:-1:-10 ;
N = 5 ; M = 4 ;
C = zeros(N,M) ;
C(:,1) = randsample(C1',5) ;
C(:,2) = randsample(C2',5) ;
C(:,3) = randsample(C3',5) ;
C(:,4) = randsample(C4',5) ;
  3 Kommentare
KSSV
KSSV am 23 Apr. 2020
Bearbeitet: KSSV am 23 Apr. 2020
You split the big number into multiples and pick from each column.
You can use repmat on C1, repeat the values and pick them at once.
Varun Pai
Varun Pai am 23 Apr. 2020
That's great... Thank you for the suggestion.
function ParameterSet = GenerateRandomSet(MinVal,MaxVal,StepVal,N)
% MinVal : 1 x M array of Lower limit
% MaxVal : 1 x M array of Upper limit
% StepVal : 1 x M array of Step values
% N : ParameterSet row size
% Usage eg. GenerateRandomSet([0 0 2 0],[1 10 8 -10],[0.1 1 0.5 -1],50)
rows = N;
cols = length(MinVal);
ParameterSet = zeros(rows,cols);
for c = 1:cols
ParamVectors = MinVal(c):StepVal(c):MaxVal(c);
repfactor = floor(N/length(ParamVectors)) + 1;
ParamVectors = repmat(ParamVectors,1,repfactor);
ParameterSet(:,c) = randsample(ParamVectors',N);
end
end

Melden Sie sich an, um zu kommentieren.

Weitere Antworten (1)

madhan ravi
madhan ravi am 23 Apr. 2020
Hint example:
x = 1:10;
N = 5;
x(randi(numel(x),1,N))

Kategorien

Mehr zu Random Number Generation finden Sie in Help Center und File Exchange

Produkte


Version

R2020a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by