non zero elements above 70 and below -70 zero

hello people,

In a matrix I want that all non zero elements above 70 and below -70 is zero.

How do I do that ?

Thank you!

Answer 1

[Honglei Chen]

Use logical index

x(x>70 | x<-70)=0

[Jeroen]

and what if I want to replace only those elements in the first two rows?

[Honglei Chen]

See carmen's answer below

Answer 2

[the cyclist]

I am not 100% sure what you mean, but here is some code (with comments on my understanding) that you should be able to modify to do what you want

% Some test data:
A = 200*rand(100) - 100;

% Index to values you want to zero out
idx = (A>70) | (A<-70); % Index to values that are bigger than 70 or smaller than -70

% Zero those out
A(idx) = 0;

[Jeroen]

Thank you!

Well it is a matrix of ~40000 by 6. But what if I want to replace only those elements in the first two rows?

Answer 3

[carmen]

then you modify Honglei Chen 's approach according to your wish:

x(1:2,x(1:2,:)>70 | x(1:2,:)<-70)=0

that should be it.

Answer 4

[Sean de Wolski]

A(abs(A)>70) = 0;