MATLAB Answers

0

how do I substitute all negative values in a vector with a random number between 0 and 2

Asked by Malavan Subramaniam on 17 Sep 2019
Latest activity Answered by Shounak Shastri on 17 Sep 2019
How do I substitute all negative values in a vector (called y) with a random number between 0 and 2?

  0 Comments

Sign in to comment.

3 Answers

Answer by per isakson
on 17 Sep 2019

One way
>> Y = randi( [-4,4], 1,12 ); % sample vector
>> isneg = Y < 0;
>> Y( isneg ) = 2*rand( 1, sum(isneg) )
Y = Columns 1 through 10
2 0.69135 0 2 0 0.72759 1.7308 2 0 3
Columns 11 through 12
1 0

  0 Comments

Sign in to comment.


Answer by Stephan
on 17 Sep 2019

y(y<0) = 2*rand(1,numel(y(y<0)))

  0 Comments

Sign in to comment.


Answer by Shounak Shastri on 17 Sep 2019

The simplest (but not the most efficient) way to do this would be to inititalize a for loop and run through all the elements one-by-one.
for ii = 1:length(y)
if y(ii) < 0
y(ii) = randi([0, 2]);
end
end
The function randi() generates a random number bertween the limits given in the square brackets, in this case 0 and 2.
A better (faster and more efficient in terms of lines of code) way to do this would be
y (y < 0) = randi([0, 2]);

  0 Comments

Sign in to comment.