Problem with variables...

Transformer · September 28th, 2011, 03:56 AM

Hi there gurus!

I am new to XML and XSLT, so my quiestion should be an easy one for you.
What i am trying to do is get average from CD 'price' element.

I failed using 'sequence' to get all avalues from price element. So i decided to 1) get SUM on price and store it in 'mySum' variable 2) get COUNT of the CDs and store it in 'myCount' 3) get value of '$mySum/$myCount' and store it in myRes variable.

The following code works fine and i see the values:

Code:

<xsl:variable name="mySum" select="sum(catalog/cd/price)"></xsl:variable>
<xsl:variable name="myCount" select="count(catalog/cd)"></xsl:variable>
<td><xsl:value-of select="$mySum"/></td>
<td><xsl:value-of select="$myCount"/></td>

but when i try:

Code:

<xsl:variable name="mySum" select="sum(catalog/cd/price)"></xsl:variable>
<xsl:variable name="myCount" select="count(catalog/cd)"></xsl:variable>
<td><xsl:value-of select="$mySum/$myCount"/></td>

or

Code:

<xsl:variable name="mySum" select="sum(catalog/cd/price)"></xsl:variable>
<xsl:variable name="myCount" select="count(catalog/cd)"></xsl:variable>
<xsl:variable name="myRes" select="$mySum/$myCount"/></xsl:variable>
<td><xsl:value-of select="$myRes"/></td>

it fails...

Can you guys help me out here?

Thanks in advance!

Martin Honnen · September 28th, 2011, 05:55 AM

Well with the XSLT/XPath syntax the "/" character is used to separate steps in a path expression, not as a numerical operator. If you look at http://www.w3.org/TR/xpath/#numbers then you see the "div" is the operator for floating point division.

Code:

select="$mySum div $myCount"

You should also be aware that with XSLT/XPath 2.0 there is a function avg http://www.w3.org/TR/xpath-functions/#func-avg to compute the average.

Transformer · September 28th, 2011, 06:22 AM

Hi Martin!

Thanks for the reply, you are absolutely right about that. I have just realized that myself and i opened my topic to write that i have found that you are already pointed to it.

I don't know why i didn't saw this at first time. Anyway, i'll be more accurate from now on.

About that #func-avg... I have found it lately, but had some problems with sequence, so that is why i decided to calculate by hand.

One more question: current select="$mySum div $myCount" gives me plenty numbers after coma. How can i set precision of that variable to show only 2 numbers after coma? I tried to put 'as="xs:decimal*"' in <xsl:variable> but the error is: "'as' is an invalid attribute for the 'xsl:variable' element."
Any ideas?

Thanks again!
XSLTransformer.

Martin Honnen · September 28th, 2011, 06:30 AM

XSLT has format-number function http://www.w3.org/TR/xslt#format-number:

Code:

format-number($mySum div $myCount, '#.00')

As for your failing attempts to use the avg function or the as attribute, make sure you use an XSLT 2.0 processor like Saxon 9, AltovaXML, XQSharp. Then you can use those features, otherwise not.