The Rounding Environment Variable - Maple Programming Help

The Rounding Environment Variable

 Calling Sequence Rounding := x

Parameters

 x - one of 0, nearest, infinity, -infinity, simple

Description

 • The Rounding environment variable controls the rounding of floating-point results.
 • There are five rounding modes available in Maple.

 Rounding Mode Meaning nearest round to the nearest possible value, with ties resolved by rounding to the nearest even 0 round towards zero infinity round towards positive infinity -infinity round towards negative infinity simple round to the nearest possible value, with ties resolved by rounding up

 • The value of Rounding is changed by using the assignment operator.  The default value of Rounding is nearest.
 • To determine the current value of Rounding during a Maple session, enter the command Rounding;.
 • The rounding mode determines the sign of 0 when it cannot be obtained otherwise.
 • Infinities always round to themselves, independent of the rounding value.
 • Maple fully evaluates environment variables such as Rounding. Because Rounding is an environment variable, any assignments to it inside a procedure body are undone upon exit from the procedure.

Examples

 > $\mathrm{Rounding}$
 ${\mathrm{nearest}}$ (1)
 > f := proc()     print( "Entering f. Rounding is", Rounding );     Rounding := -infinity;     print( "The current value of Rounding is", Rounding ); end proc:
 > $f\left(\right)$
 ${"Entering f. Rounding is"}{,}{\mathrm{nearest}}$
 ${"The current value of Rounding is"}{,}{-}{\mathrm{∞}}$ (2)
 > $\mathrm{Rounding}$
 ${\mathrm{nearest}}$ (3)

When returning from f in the procedure above, Maple resets Rounding to its value on entry to f.

 > ${1.4}^{10}$
 ${28.92546550}$ (4)
 > $\mathrm{Rounding}≔0$
 ${\mathrm{Rounding}}{≔}{0}$ (5)
 > ${1.4}^{10}$
 ${28.92546549}$ (6)
 > $\mathrm{Rounding}≔\mathrm{nearest}$
 ${\mathrm{Rounding}}{≔}{\mathrm{nearest}}$ (7)
 > $2.-2.$
 ${0.}$ (8)
 > $\mathrm{Rounding}≔-\mathrm{∞}$
 ${\mathrm{Rounding}}{≔}{-}{\mathrm{∞}}$ (9)
 > $2.-2.$
 ${-}{0.}$ (10)