Determine if a value is an Empty Matrix: 0 x 1 and replace with NaN

Hello. In my code I'm attempting to locate the max value of a variable. Unfortunately for doing max(variable) it gives an error if the matrix is a []. I was trying to figure out how to properly write my if else loop to put in NaN to a previously defined array if its a [] and if not, to calculate the value. My code is as follows:

if l == 1 
   fint=intersect(find(b(:,1)==k),find(b(:,2)==l))
if fint == []
          high_maxT_mo(k - (minyear-1),1) = NaN
          else
             high_maxT_mo(k - (minyear-1),1) = nanmax(maxtemp(fint))
          end
end

I get the following:

fint =

   Empty matrix: 0-by-1

Error using == Matrix dimensions must agree.

Thanks!

[Theodore]

k is a variable defined in my for loop spanning from k=minyear:maxyear.

Answer 1

[Evan]

help isempty

Your code would look something like this:

if l == 1
    fint = intersect(find(b(:,1)==k),find(b(:,2)==l))
    if isemty(fint)
        high_maxT_mo(k - (minyear-1),1) = NaN
    else
        high_maxT_mo(k - (minyear-1),1) = nanmax(maxtemp(fint))
    end
end

[Theodore]

Awesome! Thanks so much! Worked perfectly!

Answer 2

[Jan]

A simplification for:

fint=intersect(find(b(:,1)==k),find(b(:,2)==l))

is:

fint = find(b(:,1)==k & b(:,2)==l)

[Theodore]

Thanks Jan!

Answer 3

[the cyclist]

Rather than doing an equality comparison

if fint == [],

use the isempty function:

if isempty(fint)

[Theodore]

Thanks guys! worked great!