vec_tstnan

Purpose

Returns a vector whose elements depend on if the value of the corresponding element of a or b is NaN.

Syntax

d=vec_tstnan(a, b)

Result and argument types

The following table describes the types of the returned value and the function arguments.

d	a	b
`vector4double`	`vector4double`	`vector4double`

Result value

The value of each element of the result is 1.0 if the corresponding element of a or b is a NaN, otherwise the value is -1.0.

Formula

If ((a[0] EQ NaN) or (b[0] EQ NaN)) Then d[0] = 1.0 Else d[0] = -1.0
If ((a[1] EQ NaN) or (b[1] EQ NaN)) Then d[1] = 1.0 Else d[1] = -1.0
If ((a[2] EQ NaN) or (b[2] EQ NaN)) Then d[2] = 1.0 Else d[2] = -1.0
If ((a[3] EQ NaN) or (b[3] EQ NaN)) Then d[3] = 1.0 Else d[3] = -1.0

Note: EQ is the equal operator.

Example

a =  (10.0, 20.0,  NaN, 40.0)
b =  (50.0,  NaN, 70.0, 80.0)
d: (-1.0,  1.0,  1.0, -1.0)