Name

isnan - test whether or not a scalar or each vector component is not-a-number

Synopsis

bool  isnan(float x);
bool1 isnan(float1 x);
bool2 isnan(float2 x);
bool3 isnan(float3 x);
bool4 isnan(float4 x);

bool   isnan(half x);
bool1  isnan(half1 x);
bool2  isnan(half2 x);
bool3  isnan(half3 x);
bool4  isnan(half4 x);

bool  isnan(fixed x);
bool1 isnan(fixed1 x);
bool2 isnan(fixed2 x);
bool3 isnan(fixed3 x);
bool4 isnan(fixed4 x);

Parameters

x

Vector or scalar to test for being NaN.

Description

Returns whether or not a scalar or each vector component is not-a-number (NaN) Finite and infinite values are not NaN.

Reference Implementation

isnan for float3 vectors could be implemented like this.

bool3 isnan(float3 s)
{
  // By IEEE 754 rule, NaN is not equal to NaN
  return s != s;
}

Profile Support

isnan is supported in all profiles except fp20.

See Also

isfinite, isinf