$ZTAN (ObjectScript)
Synopsis
$ZTAN(n)
Argument
| Argument | Description |
|---|---|
| n | An angle in radians ranging from Pi to 2 Pi (inclusive). Other supplied numeric values are converted to a value within this range. |
Description
$ZTAN returns the trigonometric tangent of n. The result is a signed decimal number.
$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. $ZTAN(0) is 0.
Argument
n
An angle in radians ranging from 0 to 2 Pi. It can be specified as a value, a variable, or an expression.
A non-numeric string is evaluated as 0. For evaluation of mixed numeric strings and non-numeric strings, refer to Strings As Numbers.
Examples
The following example permits you to compute the tangent of a number:
READ "Input a number: ",num
WRITE !,"the tangent is: ",$ZTAN(num)
QUITThe 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))
