NaN entries problem !

Hello! I have 2 matrices which I would like to add them (simple addition +) but I get in the resulting matrix some NaN entries , Knowing that non of the 2 matrices contain not even a one NaN entry , I would like to know how these NaN entries are generated and how can I get rid of them ?! I have used the following code to see where is the problem

   A1=find(isnan(MATRIX11(1000:1500,1000:1500)+MATRIX21(1000:1500,1000:1500)));

and I get A1=[] (empty) and I have changed the intervals (1000:1500) several timeand I keep getting A1 empty but as I change (1:end) A1 is not empty Note: I couldn't attach the matrices they are larger then the permitted size! Thank you!

Answer 1

[Steven Lord]

One possibility:

>> x = -Inf;
>> y = Inf;
>> z = x+y
z =
   NaN