if-then-else shortcut

shortcut for simple if conditions.
The function works similar to Excel format.
First argument is the condition, second is what to do if true, third is what to do if false.

example 1:
A = ifelse(x>thr, 5, 3)
will execute:
if x>thr
A = 5
else
A = 3
end

example 2:
A = ifelse(im>thr, im*2, im/2)
will execute:
A = im*2 where im>thr
A = im/2 where im<=thr

example 3:
ifelse(x~=0, 'y=1/x;', 'disp ''x is zero''')
will execute:
if x~=0
y = 1/x;
else
disp 'x is zero'
end