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Posted to users@daffodil.apache.org by "Costello, Roger L." <co...@mitre.org> on 2019/09/04 17:18:37 UTC
Non-terminating decimal expansion ... huh?
Hello DFDL community,
The below DFDL schema produces this error message:
[error] Parse Error: Non-terminating decimal expansion; no exact representable decimal result. (within Expression Evaluation Error: Non-terminating decimal expansion; no exact representable decimal result.
What does that mean? Why am I getting it? How to fix it? /Roger
<xs:element name="input">
<xs:complexType>
<xs:sequence>
<xs:element name="command-code" type="unsignedint3" />
<xs:element name="longitude">
<xs:complexType>
<xs:sequence>
<xs:element name="raw" type="unsignedint24" />
<xs:element name="degrees" type="xs:string" dfdl:inputValueCalc="{
if (../raw eq 0) then '0 degrees'
else if (../raw lt 8388607) then fn:concat((../raw * 180 div 8388607), ' degrees east')
else fn:concat('-',((../raw - 8388607) * 180 div 8388607), ' degrees west')
}" />
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="area-code" type="unsignedint5" />
</xs:sequence>
</xs:complexType>
</xs:element>
Re: Non-terminating decimal expansion ... huh?
Posted by Steve Lawrence <sl...@apache.org>.
I can't find anything in the XPath specification that discusses
precision on xs:decimal division. I did find this Saxon documentation
[1] on how they handle it:
> In the case of decimal division, the precision is the sum of the precisions of the two operands, plus six.
I dont' see that in the spec either, so maybe this is implementation
defined?
It it was up to us, it would probably be nice allow something like
xs:decimal(180) div xs:decimal(8388607)
to work with a reasonable level of precision without needing to convert
to double/float.
- Steve
[1] https://www.saxonica.com/html/documentation/expressions/arithmetic.html
On 9/4/19 1:39 PM, Beckerle, Mike wrote:
> Should this produce a decimal, rounded to some number of fraction digits, or
> convert to floating point?
>
>
> --------------------------------------------------------------------------------
> *From:* Steve Lawrence <sl...@apache.org>
> *Sent:* Wednesday, September 4, 2019 1:35 PM
> *To:* users@daffodil.apache.org <us...@daffodil.apache.org>
> *Subject:* Re: Non-terminating decimal expansion ... huh?
> This seems like a bug in our DFDL expression implementation to me. A
> small example that reproduces this is the expression:
>
> xs:decimal(180) div xs:decimal(8388607)
>
> But this works on a couple of XPath test implementations I've tried. I'd
> guess that Daffodil needs to provide a rounding method so that we don't
> get these infinite decimal errors.
>
> Though, the xs:double does seem like the right workaround.
>
>
> On 9/4/19 1:27 PM, Beckerle, Mike wrote:
>> You are doing divisions among integers.
>>
>> If you want it to convert to floating point you need to be explicit.
>>
>> Otherwise it tries to keep things as decimal, but clearly that can't work for
>> division.
>>
>> I suggest changing your 180 constants to xs:double(180) That should force
>> everything to convert into double-precision floating point.
>> --------------------------------------------------------------------------------
>> *From:* Costello, Roger L. <co...@mitre.org>
>> *Sent:* Wednesday, September 4, 2019 1:18 PM
>> *To:* users@daffodil.apache.org <us...@daffodil.apache.org>
>> *Subject:* Non-terminating decimal expansion ... huh?
>>
>> Hello DFDL community,
>>
>> The below DFDL schema produces this error message:
>>
>> *[error] Parse Error: Non-terminating decimal expansion; no exact representable
>> decimal result. (within Expression Evaluation Error: Non-terminating decimal
>> expansion; no exact representable decimal result.*
>>
>> What does that mean? Why am I getting it? How to fix it? /Roger
>>
>> <xs:elementname="input">
>> <xs:complexType>
>> <xs:sequence>
>> <xs:elementname="command-code"type="unsignedint3"/>
>> <xs:elementname="longitude">
>> <xs:complexType>
>> <xs:sequence>
>> <xs:elementname="raw"type="unsignedint24"/>
>> <xs:elementname="degrees"type="xs:string"dfdl:inputValueCalc="{
>> if (../raw eq 0) then '0 degrees'
>> else if (../raw lt 8388607) then fn:concat((../raw
>> * 180 div 8388607), ' degrees east')
>> else fn:concat('-',((../raw - 8388607) * 180 div
>> 8388607), ' degrees west')
>> }"/>
>> </xs:sequence>
>> </xs:complexType>
>> </xs:element>
>> <xs:elementname="area-code"type="unsignedint5"/>
>> </xs:sequence>
>> </xs:complexType>
>> </xs:element>
>>
>
Re: Non-terminating decimal expansion ... huh?
Posted by "Beckerle, Mike" <mb...@tresys.com>.
Should this produce a decimal, rounded to some number of fraction digits, or convert to floating point?
________________________________
From: Steve Lawrence <sl...@apache.org>
Sent: Wednesday, September 4, 2019 1:35 PM
To: users@daffodil.apache.org <us...@daffodil.apache.org>
Subject: Re: Non-terminating decimal expansion ... huh?
This seems like a bug in our DFDL expression implementation to me. A
small example that reproduces this is the expression:
xs:decimal(180) div xs:decimal(8388607)
But this works on a couple of XPath test implementations I've tried. I'd
guess that Daffodil needs to provide a rounding method so that we don't
get these infinite decimal errors.
Though, the xs:double does seem like the right workaround.
On 9/4/19 1:27 PM, Beckerle, Mike wrote:
> You are doing divisions among integers.
>
> If you want it to convert to floating point you need to be explicit.
>
> Otherwise it tries to keep things as decimal, but clearly that can't work for
> division.
>
> I suggest changing your 180 constants to xs:double(180) That should force
> everything to convert into double-precision floating point.
> --------------------------------------------------------------------------------
> *From:* Costello, Roger L. <co...@mitre.org>
> *Sent:* Wednesday, September 4, 2019 1:18 PM
> *To:* users@daffodil.apache.org <us...@daffodil.apache.org>
> *Subject:* Non-terminating decimal expansion ... huh?
>
> Hello DFDL community,
>
> The below DFDL schema produces this error message:
>
> *[error] Parse Error: Non-terminating decimal expansion; no exact representable
> decimal result. (within Expression Evaluation Error: Non-terminating decimal
> expansion; no exact representable decimal result.*
>
> What does that mean? Why am I getting it? How to fix it? /Roger
>
> <xs:elementname="input">
> <xs:complexType>
> <xs:sequence>
> <xs:elementname="command-code"type="unsignedint3"/>
> <xs:elementname="longitude">
> <xs:complexType>
> <xs:sequence>
> <xs:elementname="raw"type="unsignedint24"/>
> <xs:elementname="degrees"type="xs:string"dfdl:inputValueCalc="{
> if (../raw eq 0) then '0 degrees'
> else if (../raw lt 8388607) then fn:concat((../raw
> * 180 div 8388607), ' degrees east')
> else fn:concat('-',((../raw - 8388607) * 180 div
> 8388607), ' degrees west')
> }"/>
> </xs:sequence>
> </xs:complexType>
> </xs:element>
> <xs:elementname="area-code"type="unsignedint5"/>
> </xs:sequence>
> </xs:complexType>
> </xs:element>
>
Re: Non-terminating decimal expansion ... huh?
Posted by Steve Lawrence <sl...@apache.org>.
This seems like a bug in our DFDL expression implementation to me. A
small example that reproduces this is the expression:
xs:decimal(180) div xs:decimal(8388607)
But this works on a couple of XPath test implementations I've tried. I'd
guess that Daffodil needs to provide a rounding method so that we don't
get these infinite decimal errors.
Though, the xs:double does seem like the right workaround.
On 9/4/19 1:27 PM, Beckerle, Mike wrote:
> You are doing divisions among integers.
>
> If you want it to convert to floating point you need to be explicit.
>
> Otherwise it tries to keep things as decimal, but clearly that can't work for
> division.
>
> I suggest changing your 180 constants to xs:double(180) That should force
> everything to convert into double-precision floating point.
> --------------------------------------------------------------------------------
> *From:* Costello, Roger L. <co...@mitre.org>
> *Sent:* Wednesday, September 4, 2019 1:18 PM
> *To:* users@daffodil.apache.org <us...@daffodil.apache.org>
> *Subject:* Non-terminating decimal expansion ... huh?
>
> Hello DFDL community,
>
> The below DFDL schema produces this error message:
>
> *[error] Parse Error: Non-terminating decimal expansion; no exact representable
> decimal result. (within Expression Evaluation Error: Non-terminating decimal
> expansion; no exact representable decimal result.*
>
> What does that mean? Why am I getting it? How to fix it? /Roger
>
> <xs:elementname="input">
> <xs:complexType>
> <xs:sequence>
> <xs:elementname="command-code"type="unsignedint3"/>
> <xs:elementname="longitude">
> <xs:complexType>
> <xs:sequence>
> <xs:elementname="raw"type="unsignedint24"/>
> <xs:elementname="degrees"type="xs:string"dfdl:inputValueCalc="{
> if (../raw eq 0) then '0 degrees'
> else if (../raw lt 8388607) then fn:concat((../raw
> * 180 div 8388607), ' degrees east')
> else fn:concat('-',((../raw - 8388607) * 180 div
> 8388607), ' degrees west')
> }"/>
> </xs:sequence>
> </xs:complexType>
> </xs:element>
> <xs:elementname="area-code"type="unsignedint5"/>
> </xs:sequence>
> </xs:complexType>
> </xs:element>
>
Re: Non-terminating decimal expansion ... huh?
Posted by "Beckerle, Mike" <mb...@tresys.com>.
You are doing divisions among integers.
If you want it to convert to floating point you need to be explicit.
Otherwise it tries to keep things as decimal, but clearly that can't work for division.
I suggest changing your 180 constants to xs:double(180) That should force everything to convert into double-precision floating point.
________________________________
From: Costello, Roger L. <co...@mitre.org>
Sent: Wednesday, September 4, 2019 1:18 PM
To: users@daffodil.apache.org <us...@daffodil.apache.org>
Subject: Non-terminating decimal expansion ... huh?
Hello DFDL community,
The below DFDL schema produces this error message:
[error] Parse Error: Non-terminating decimal expansion; no exact representable decimal result. (within Expression Evaluation Error: Non-terminating decimal expansion; no exact representable decimal result.
What does that mean? Why am I getting it? How to fix it? /Roger
<xs:element name="input">
<xs:complexType>
<xs:sequence>
<xs:element name="command-code" type="unsignedint3" />
<xs:element name="longitude">
<xs:complexType>
<xs:sequence>
<xs:element name="raw" type="unsignedint24" />
<xs:element name="degrees" type="xs:string" dfdl:inputValueCalc="{
if (../raw eq 0) then '0 degrees'
else if (../raw lt 8388607) then fn:concat((../raw * 180 div 8388607), ' degrees east')
else fn:concat('-',((../raw - 8388607) * 180 div 8388607), ' degrees west')
}" />
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="area-code" type="unsignedint5" />
</xs:sequence>
</xs:complexType>
</xs:element>