This interesting question came up for me today. I was looking for a simple expression that can be used in a function handle, one that produces a NaN only for elements that are already NaN, but I want it to return 0 for any other element, including +/- inf.
X = [-inf, -1, -eps, 0, realmin, 2, 1+i, pi, flintmax, realmax, inf, NaN];
That should qualify as a good list of the possible numbers in MATLAB that might be of interest.
I want my function to generate a result as the vector: [0 0 0 0 0 0 0 0 0 0 0 NaN].
For example, this fails:
Though it is close. It suffers because 0*inf generates a NaN. An as pretty one is:
It fails for a similar reason, because inf-inf produces NaN.
A valid solution should work for arrays of any shape or size of course. Yes, it is trivial to write if I do it in an m-file. Thus...
As I said, trivial if I use an m-flle. More difficult if I wish to use a function handle. It may be a blind spot on my part. But as a puzzle, can you write a simple, robust one line expression to produce my desired result, expressed as a function handle? Vectorized, of course.
And yes, I'll admit this question has essentially zero value, since a valid solution exists in an m-file form. Have fun! (I'll post a spoiler as an answer if people cannot find a better solution than the one I found. My final solution required only 9 characters, but it was definitely non-obvious.)