When you are working with numeric values, then a comparison operator returns logical false or logical true. Logical false, in most circumstances, concerns to double 0.0 and logical true in most circumstances converts to double 1.0. Therefore you can impliment
result = piecewise(CONDITION1, VALUE1, CONDITION2, VALUE2, 0)
as
(CONDITION1) .* (VALUE1) + (~CONDITION1).*(CONDITION2) .* (VALUE2)
In cases where the conditions are mutually exclusive, this can often be simplified to
(CONDITION1) .* (VALUE1) + (CONDITION2) .* (VALUE2)
However, you have to be careful that the values never become infinity for the unselected case. For example you cannot do
(x ~= 0) .* (1/x) + (x == 0) .* 1
to use 1 for x == 0 and 1/x for other x. This is because if you write like that, then at 0 you would have (x ~= 0) .* (1/0) which would be 0 (false) * infinity which would give NaN for that term, not 0.
