Linux Certif

Toute la documentation sur la certification Linux LPI

asin.3Cg

NAME

asin - returns arcsine of scalars and vectors.

SYNOPSIS

   float  asin(float a);
   float1 asin(float1 a);
   float2 asin(float2 a);
   float3 asin(float3 a);
   float4 asin(float4 a);
 
 
 

   half   asin(half a);
   half1  asin(half1 a);
   half2  asin(half2 a);
   half3  asin(half3 a);
   half4  asin(half4 a);
 
 
 

   fixed  asin(fixed a);
   fixed1 asin(fixed1 a);
   fixed2 asin(fixed2 a);
   fixed3 asin(fixed3 a);
   fixed4 asin(fixed4 a);
 
 
 

PARAMETERS

a

Vector or scalar of which to determine the arcsine.

DESCRIPTION

Returns the arcsine of a in the range [-pi/2,+pi/2], expecting a to be in the range [-1,+1].

For vectors, the returned vector contains the arcsine of each element of the input vector.

REFERENCE IMPLEMENTATION

asin for a float scalar could be implemented like this.

   // Handbook of Mathematical Functions
   // M. Abramowitz and I.A. Stegun, Ed.
 
 
 

   float asin(float x) {
     float negate = float(x < 0);
     x = abs(x);
     float ret = -0.0187293;
     ret *= x;
     ret += 0.0742610;
     ret *= x;
     ret -= 0.2121144;
     ret *= x;
     ret += 1.5707288;
     ret = 3.14159265358979*0.5 - sqrt(1.0 - x)*ret;
     return ret - 2 * negate * ret;
   }
 
 
 

PROFILE SUPPORT

asin is supported in all profiles.

Support in the fp20 is limited.

SEE ALSO

abs, acos, sin, sqrt