 Return to Archive SAS Tip of the Month February 2007 This month is a quick look at the trigonometric functions available in SAS. ``` Function Trigonometric Inverse Hyperbolic -------------------------------------------- Sine SIN ARSIN SINH Cosine COS ARCOS COSH Tangent TAN ATAN TANH``` Note that all angles that are entered using the trigonometric functions are in radians, i.e. if the angle is in degrees then this value must be multiplied by PI/180 before using the function. The following example demonstrates the use of the SIN function and returning its inverse: ``` data _null_; pi=constant('PI'); angle=30*PI/180; sinx=sin(angle); arsinx=arsin(sinx)*180/pi; put angle= sinx= arsinx= pi=; run;``` produces the output in the log ` angle=0.5235987756 sinx=0.5 arsinx=30 pi=3.1415926536` Note the use of the CONSTANT function - this function accesses certain mathematical constants, including PI, that are set within SAS. Before SAS version 8 the constant for PI did not exist so alternates were used to set a value for PI, namely setting PI to a value say 3.14159, or if more accuracy was needed setting the value to the result of ARCOS(-1). ________________________________ Updated February 11, 2007