I am working with Vivisimo 8.01 and am attempting to create Date Biasing in a Source. I am following instructions from the Velocity Training Course (Wednesday, Page 15).
In a DB Search Collection I have created a fast-indexed field called DerivedPublishDate of DataType date.
In the Source, I have set the Sorting Formula to "custom xpath expression"
The formula used below is based on the formula provided in the Velocity Guide:
$score * (1 div (1 + math:power(((<xsl:value-of select="date:seconds()"/> - $DerivedPublishDate) div 86400),200000)))
In the Admin console I get an error message "Invalid Expression".
I have tried mutliple variations and get the same message. The example in the Guide, did not use the "xsl" namespace. I added it in hopes that this would remove the parsing error. It did not. The Guide example also had an addtional right parenthesis which I tested with and without.
I've attached a file containing the Source and Search Collection
Any guidance as to what would be causing this error would be appreciated.