ObjectScript Reference
$ZTAN


Returns the trigonometric tangent of the specified angle value.
Synopsis
Parameter
$ZTAN returns the trigonometric tangent of
n. The result is a signed decimal number.
Note:
$ZTAN (like all trigonometric functions) calculates its values based on pi rounded to the number of available decimal digits. Therefore, the value returned by $ZTAN($ZPI) is –.000000000000000000462644 and $ZTAN(–$ZPI) is .000000000000000000462644. For this reason you should not perform limit tests comparing these returned values to 0. $ZTAN(0) is 0.
n
An angle in radians ranging from 0 to 2 Pi. It can be specified as a value, a variable, or an expression.
A nonnumeric string is evaluated as 0.
The following example permits you to compute the tangent of a number:
READ "Input a number: ",num
WRITE !,"the tangent is: ",$ZTAN(num)
QUIT
The following example compares the results from InterSystems IRIS fractional numbers (
$DECIMAL numbers) and
$DOUBLE numbers. In both cases, the tangent of 0 is exactly 0, but the tangent of pi is a negative fractional number (not exactly 0):
WRITE !,"the tangent is: ",$ZTAN(0.0)
WRITE !,"the tangent is: ",$ZTAN($DOUBLE(0.0))
WRITE !,"the tangent is: ",$ZTAN($ZPI)
WRITE !,"the tangent is: ",$ZTAN($DOUBLE($ZPI))
WRITE !,"the tangent is: ",$ZTAN(1.0)
WRITE !,"the tangent is: ",$ZTAN($DOUBLE(1.0))
Content Date/Time: 20190410 14:45:57