Re: Function that reduces the number of digits to the

Do you absolutely want truncation (so 4.99 becomes 4.9) or will rounding do
(so 4.99 becomes 5.0)?

If rounding will do, then use round($x, -$desired-digits).

If you really want truncation then consider the "idiv" operator, for example
(4.99 * 10 idiv 10) gives 4.9: you can construct the value 10 as math:pow(10,
$desired-digits).

Michael Kay
Saxonica

> On 23 Jun 2020, at 15:28, Roger L Costello costello@xxxxxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hi Folks,
>
> $num is a variable holding a decimal value.
>
> $desired-number-of-digits-after-decimal-point is a variable holding an
integer value.
>
> I want a function that reduces the number of digits to the right of the
decimal point in $num according to the value specified in
$desired-number-of-digits-after-decimal-point
>
> Example #1:
> $num = 42.366978
> $desired-number-of-digits-after-decimal-point = 2
> The result of applying the function is: 42.36
>
> Example #2:
> $num = 42.366978
> $desired-number-of-digits-after-decimal-point = 0
> The result of applying the function is: 42
>
> Below is one way to implement the function. Is there a better way? By
"better" I mean simpler, more correct.
>
> Also, is there a better name for the function?  By "better" I mean shorter,
more standardized. /Roger
> -----------------------------------------------------
> <xsl:function name="f:reduce-number-of-digits-after-decimal-point"
as="xs:string">
>    <xsl:param name="num" as="xs:string" />
>    <xsl:param name="desired-number-of-digits-after-decimal-point"
as="xs:integer" />
>
>    <xsl:variable name="whole-part" select="substring-before($num, '.')"/>
>    <xsl:variable name="fraction-part" select="substring-after($num, '.')"/>
>    <xsl:variable name="reduced-fraction-part"
select="substring($fraction-part, 1,
$desired-number-of-digits-after-decimal-point)"/>
>    <xsl:choose>
>        <xsl:when test="$desired-number-of-digits-after-decimal-point gt 0">
>            <xsl:value-of select="concat($whole-part, '.',
$reduced-fraction-part)"/>
>        </xsl:when>
>        <xsl:otherwise>
>            <xsl:value-of select="$whole-part"/>
>        </xsl:otherwise>
>    </xsl:choose>
> </xsl:function>