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, and negative Pi is equivalent to Pi.
A non-numeric string is evaluated as 0 and therefore $ZSEC returns 1. For evaluation of mixed numeric strings and non-numeric strings, refer to Strings As Numbers in Using ObjectScript.