I have a function file that I worked out myself, all I need to do is apply it to an array of values but it's not working, I'd appreciate any help.

Here is my function file so far

function x=isoddm(a)

if isnan(a)==1

      x=-1;
  elseif mod(a,2)==0.5
      x=-1;
  elseif mod(a,2)==1.5
      x=-1;
  elseif mod(a,2)==0
      x=0;
  elseif mod(a,2)==1
      x=1;
  end

All I need to do is apply it to an array. Here is an example array a=[7 4.5 nan] and its result isoddm([7 4.5 nan])

[Image Analyst]

What does "oddm([7 4.5 nan])" mean?

[Marco]

the [7 4.5 nan] part is the array I entered, the isoddm() around it is the function, it means that the array hasn't been evaluated

Answer 1

[Image Analyst]

You don't have a plain "else" condition and since none of the conditions that you do have are satisfied, none of the If/else blocks get entered, and so x never gets defined. Here, check out this helpful link: http://blogs.mathworks.com/videos/2012/07/03/debugging-in-matlab/

[Marco]

Thank you for the tip, my problem is that I'm trying to use this function file on an array, how do I do that?

[Image Analyst]

Why not just put into a loop over k to calculate x(k) as a function of a(k):

for k = 1 : numel(a)
  if isnan(a(k))==1
      x(k)=-1;
  elseif mod(a(k),2)==0.5
      x(k)=-1;
  elseif mod(a(k),2)==1.5
      x(k)=-1;
  elseif mod(a(k),2)==0
      x(k)=0;
  elseif mod(a(k),2)==1
      x(k)=1;
  else
      x(k) = nan;
  end
end

Regarding comparing to .5 and 1.5, see the FAQ: http://matlab.wikia.com/wiki/FAQ#Why_is_0.3_-_0.2_-_0.1_.28or_similar.29_not_equal_to_zero.3F