An angle in radians ranging from Pi to 2 Pi (inclusive). It can be specified as a value, a variable, or an expression. You can specify the value Pi by using the $ZPI special variable. You can specify positive or negative values smaller than Pi or larger than 2 Pi; InterSystems IRIS resolve these values to the corresponding multiple of Pi. For example, 3 Pi is equivalent to Pi, negative Pi is equivalent to Pi, and zero is equivalent to 2 Pi.
The following example permits you to compute the cosine of a number:
READ"Input a number: ",numIF$ZABS(num)>(2*$ZPI){WRITE!,"number is a larger than 2 pi"}ELSE{WRITE!,"the cosine is: ",$ZCOS(num)}QUIT
The following example compares the results from InterSystems IRIS fractional numbers ($DECIMAL numbers) and $DOUBLE numbers. In both cases, the cosine of 0 is exactly 1, the cosine of pi is exactly -1:
WRITE!,"the cosine is: ",$ZCOS(0.0)WRITE!,"the cosine is: ",$ZCOS($DOUBLE(0.0))WRITE!,"the cosine is: ",$ZCOS(1.0)WRITE!,"the cosine is: ",$ZCOS($DOUBLE(1.0))WRITE!,"the cosine is: ",$ZCOS($ZPI)WRITE!,"the cosine is: ",$ZCOS($DOUBLE($ZPI))