Please note that the recommended version of Scilab is 6.1.1. This page might be outdated.
See the recommended documentation of this function
check for "Not a Number" entries
real or complex vector or matrix r : boolean vector or matrix
isnan(x) returns a boolean vector or matrix which
contains true entries corresponding with "Not a Number"
x entries and false entries corresponding with regular
In this paragraph, we give the reason of the existence of this function.
Consider the floating point number
x and assume that
we want to know if this number is a Not A Number.
(x==%nan) is false if
x is equal
%nan. This is why the function
isnan is helpful: it allows to
see if a floating point number is a NaN, without actually comparing its value
isnan([1 0.01 -%nan %inf-%inf])
In the following example, we see that
%nan has very particular
comparison properties and compare the result with the
%nan == %nan %nan <> %nan isnan(%nan)
In the following example, we extract the non-NaNs values
y from the array
x = [1 2 %nan 3 %nan 4] k = find(~isnan(x)) y = x(k)
|<< isinf||Floating point||nearfloat >>|