Re: [xsl] Saxon Div Issue

["Michael Kay mike@xxxxxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Unless you are using schema-aware stylesheets, the result of your expression
/xpath/num when used in an arithmetic expression will first be atomized to
create an untyped atomic value, and will then be converted to an xs:double, so
the arithmetic will be done with double-precision floating-point arithmetic.
The conversion of the string "9.88" to an xs:double produces a value that is
not exactly 9.88, because decimal fractions in general cannot be exactly
represented in binary.

Michael Kay
Saxonica
mike@xxxxxxxxxxxx
+44 (0) 118 946 5893




On 19 Jan 2015, at 16:03, Mailing Lists Mail daktapaal@xxxxxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:

> THe problem is , I dont know what will come in the $num. It is an
> xpath. It comes from an XML element.
>
> SO sometimes, the element contains 988, and sometimes it contains 98.8
> .. so my pseudo code actually is :"
>
> $num = /xpath/num
> var result = $num div 100
>
> I wouldn't know if it will be a double that I will be a decimal.
>
> Dak
>
>
> On Mon, Jan 19, 2015 at 10:57 AM, G. Ken Holman g.ken.holman@xxxxxxxxx
> <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>> At 2015-01-19 15:46 +0000, Mailing Lists Mail daktapaal@xxxxxxxxx wrote:
>>>
>>> I have a value 9.88 , I use the div  to do an operation
>>>
>>> Pseudo code:
>>>
>>> var num = 9.88
>>> var result = $num div 100
>>>
>>> I expect 0.0988 .. I get 0.09880000000000001
>>>
>>> I am using Saxon-EE-9.5.1-5.jar
>>>
>>> What is happening?
>>
>>
>> What is happening is that doing the arithmetic with the binary
>> representations of 9.88 and 100 create a result in binary that when
>> precisely converted to decimal give you the result you see.
>>
>> As Martin suggests, if you are using XSLT 2 then you can use decimal
>> representations of your values and do arithmetic with those.
>>
>> I hope this helps understand the issue.
>>
>> . . . . . . Ken
>>
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