Distinguish 'inf' and '-inf'

Question

How can I separate inf and -inf from each other?

I have matrix that contains inf and -inf and I want to replace them with 1e6 and -1e6 respectively.

for example,

a = [1 2 3 0 3 4]./[1 1 1 0 1 0];
b = log2([0 2 1 2 1 2]);
c = cat(1,a,b);

which is,

c = [  1     2     3   NaN     3   Inf;
    -Inf     1     0     1     0     1];

I want,

newc = [   1   2   3   NaN   3   1e6;
        -1e6   1   0     1   0     1];

I couldn't find a function that separates them.

Thanks.

Answer 1

You can detect inf using isinf(), and you can detect sign using sign(). Combine the two:

newc = c;
inf_filter = isinf(newc);
newc(inf_filter) = 1e6 * sign(newc(inf_filter));