# Mathematical operation on arrays

2 views (last 30 days)
Mohammed Lamine Mekhalfia on 18 Aug 2021
Commented: the cyclist on 19 Aug 2021
Dear All, I hope that all are well. I have 4 column vectors, a b c and d. I would like to write a code that take a random value for the first vector a and using that value to delete each value less than it from the vectors b c and d... delete not transfer them to zeros.
I would highly appreciate your help.
##### 2 CommentsShowHide 1 older comment
Mohammed Lamine Mekhalfia on 18 Aug 2021
The values that are less than the value chosen from the first vector

the cyclist on 18 Aug 2021
% Set random number seed, for reproducible results in this example
rng default
% Make up the input data
N = 7;
a = rand(N,1);
b = rand(N,1);
c = rand(N,1);
d = rand(N,1);
% Pick random value from a
a_rand = a(randi(numel(a)));
% Delete values from other vectors if they are less than a_rand
b(b<a_rand) = [];
c(c<a_rand) = [];
d(d<a_rand) = [];
% Show the sizes of the resulting vectors
size(a)
ans = 1×2
7 1
size(b)
ans = 1×2
4 1
size(c)
ans = 1×2
5 1
size(d)
ans = 1×2
5 1
the cyclist on 19 Aug 2021
a_rand = a(randi(numel(a)));
use
a(2)
as the value.
This is a very basic MATLAB question. You might want to watch the MATLAB Onramp tutorial to learn the basics.

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