[XSL-LIST Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Efficently transposing tokenized data
Hi XSL-List members, I have been learning my way around XSLT (2.0) over the past couple of weeks, principally using Saxon-B 9.1. I have an immediate need to transform existing XML data, initially to HTML. The XML contains, similar to SVG, space-tokenized numerical data held within attributes. What I am having trouble understanding is how to transform several nodes with such data into individual columns of data. The XML is like this: <MultiLine samples="5"> <Line title="Line 1" data="0.1 0.4 0.6 0.4 0..8" /> <Line title="Line 2" data="0.4 0.2 0.5 1.4 3.8" /> </MultiLine> There can be any number of <Line> nodes (typically 3 or 4) and the number of values (samples) in each data attribute for each <Line> must match the samples attribute of the parent <MultiLine> node. The number of samples can be very long, typically several thousand. At present this is the data that I am being supplied, so regardless of any shortcomings of the structure (although suggestions for improvement are welcome) I am stuck with it. I want to transform such data into, e.g., HTML columns, like: <TABLE> <TR> <TH>Line 1</TH><TH>Line 2</TH> </TR> <TR> <TD>0.1</TD><TD>0.4</TD> </TR> <TR> <TD>0.4</TD><TD>0.2</TD> </TR> <TR> <TD>0.6</TD><TD>0.5</TD> </TR> ... </TABLE> I have seen similar questions where people have wanted to transpose HTML table data, but the problem here is that the input data has to be tokenized. I can output the data sequentially for each Line with a template such as: <xsl:template match="Line"> <TR><TH><xsl:value-of select="@title" /></TH><TR> <xsl:for-each select="tokenize(@data,' ')"> <TR><TD> <xsl:value-of select="position()" /> </TD></TR> <xsl:value-of select="." /> </xsl:for-each> </xsl:template> To format the data as adjacent columns the only approach I can think of is a for-each loop over the number of samples, and in each case call index-at(tokenize(../Line[n]/@data, ' '), position()) for each Line. But this looks horribly inefficient, since I appear to be tokenizing every @data attribute repeatedly, presumably giving complexity O(count(Line)*samples^2). What would be far more preferable is to tokenize all the lines, and then at each index obtain the appropriate value from each sequence. But I have no idea how to do that in XSLT. I have spent at least a day trying to solve this conumdrum, so if anyone has any suggestions I would be very grateful. Kind regards, Beldaz Search 1000's of available singles in your area at the new Yahoo!7 Dating. Get Started http://au.dating.yahoo.com/?cid=53151&pid=1011
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