Index 1 Variable by another

Hi there!

I have 2 variables

if true
A = 1
    2
    NaN
    4

end
B= 20
   2
   5
   4
end

I want to remove the '5' from variable B by replacing it with a NaN (i.e. any NaN's in variable A result in a NaN in variable B

I understand this is a simple problem. I have researched but its been a long day Please help x

Answer 1

[Star Strider]

Use ‘logical indexing’:

B(isnan(A)) = NaN

produces:

B =

      20
       2
     NaN
       4

[Hillaryfor2016]

Worked beautifully, thanks for the help!! x

[Star Strider]

My pleasure!