xml - XSLT pass regex-group() value to variable and formatting it -

i have not find clear example on how this. want pass 2 regex-group result variable inside analyse-string 1 should tranformed hexadecimal decimal. example take regex-group(2)=2 , regex-group(4)=30, regex-group(4) should formated 0.30 both value passed variable lets $rg2 $rg4 calculating "($rg4*(100 div 60))+$rg2" "(0.30*(100 div 60))+2"=2.5 . if rg4=0.38 final result 2.6333333333333333

    <xsl:analyze-string select="sbtime/@stmerid" regex="([hm]{{1}})([0-9]{{1,2}})([ew]{{1}})([0-9]{{0,2}})">         <xsl:matching-substring>             <xsl:choose>                 <xsl:when test="regex-group(1) = 'm'">                     <xsl:choose>                         <xsl:when test="regex-group(3) = 'e'">                             <xsl:text>-</xsl:text>                         </xsl:when>                         <xsl:otherwise>                             <xsl:text>+</xsl:text>                         </xsl:otherwise>                     </xsl:choose>                     <xsl:choose>                         <xsl:when test="regex-group(4) != ''">                             <xsl:text>:</xsl:text>                             <xsl:variable name="rg2" as="xs:float">{regex-group(2)}</xsl:variable>                             <xsl:variable name="rg4" as="xs:float">fn:format-number({regex-group(4)},'#.##')</xsl:variable>                             <xsl:value-of select="($rg4*(100 div 60))+$rg2"/>                         </xsl:when>                         <xsl:otherwise>                             <xsl:number value="regex-group(2)" format="1"/>                         </xsl:otherwise>                     </xsl:choose>                     <xsl:number value="regex-group(2)" format="1"/>                 </xsl:when>                 <xsl:otherwise>                     <xsl:choose>                         <xsl:when test="regex-group(3) = 'e'">                             <xsl:text>-</xsl:text>                         </xsl:when>                         <xsl:otherwise>                             <xsl:text>+</xsl:text>                         </xsl:otherwise>                     </xsl:choose>                     <xsl:if test="regex-group(1) = 'm'"><xsl:text>00:</xsl:text></xsl:if>                     <xsl:number value="regex-group(2)" format="1"/>                     <xsl:choose>                         <xsl:when test="regex-group(4) != ''">                             <xsl:text>:</xsl:text>                             <xsl:number value="regex-group(4)" format="1"/>                         </xsl:when>                         <xsl:otherwise>                         </xsl:otherwise>                     </xsl:choose>                 </xsl:otherwise>             </xsl:choose>         </xsl:matching-substring>     </xsl:analyze-string> 

how ? there clean , fast way. don't know if have use variable or if there problem of scope , cast values in xslt.

edit: think ask question because tried this:

<xsl:variable name="rg2" select="regex-group(2)"/> <xsl:variable name="rg4" select="regex-group(4)"/> <xsl:value-of select="((0.$rg4)*(100 div 60))+$rg2"/> 

and returned "not valid instance of x-path grammar" in xmlspy not sure on how handle number , math add "0." in front of $rg4 string.

the syntax bind result of evaluation xpath expression (like function call regex-group(2) is) simply

<xsl:variable name="rg2" select="regex-group(2)"/> 

<xsl:variable name="rg2" as="xs:float">{regex-group(2)}</xsl:variable> might in xslt 3.0 expand-text="yes" set.

in general, if have string (like returned regex-group()) , need number of type call constructor e.g.

<xsl:variable name="rg2" select="xs:decimal(regex-group(2))"/> 

for arithmetic computation ($rg4*(100 div 60))+$rg2 need 2 numeric values while format-number give string guess rather want define

<xsl:variable name="rg4" select="xs:decimal(regex-group(4)) div 100"/>