Fast way to replace elements in a matrix?

Hi,

for eample I have an a matrix

a =

   245   255   255
   254   252   255
   251   250   239

rules:

find the row index where all 3 numbers in the row are greater than 250.

Is there a faster way to achieve it than do it in a loop?

[Stephen23]

Note that the question specifically asks for "Fast way to replace elements in a matrix?", and in real code (not just an assignment) logical indexing would likely be used as it avoids the find call:

https://www.mathworks.com/help/matlab/math/array-indexing.html

[madhan ravi]

Agree with Stephen , I used find() to explicitly show which row it was.

Answer 1

[madhan ravi]

idx=all(a>250,2) % logical index
L_idx=find(idx) % linear index , gives row number