| Some IDL_Number documentation quirks [message #93945] |
Fri, 02 December 2016 11:14  |
wlandsman
Messages: 743
Registered: June 2000
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Senior Member |
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A few quirks in the IDL documentation for IDL_Number
http://www.harrisgeospatial.com/docs/IDL_Number.html
1. The example for IDL_Number::Median method reads
*********
Print the median value of a number:
num = -24601
PRINT, num.Median( )
IDL prints:
24601
**********
Huh? The median of a negative scalar is its absolute value? I then realized that this example is probably an unfinished copy/paste from the IDL_Number:Signum method. But
2. The example for IDL Number::Signum is incorrect
*********************************
Print the signum value of a number:
num = -24601
PRINT, num.Signum( )
IDL prints:
24601
***********************************
This is closer but still incorrect. The value of num.signum() should be -1 (the sign of the number).
3. The documentation of IDL_Number::Total is incomplete.
**************
Arguments
None.
Keywords
None.
***********
But in fact, although not documented, the dimension argument and five keywords available to the TOTAL() function are also available to IDL_Number::Total. For example
IDL> a = indgen(3,3)
IDL> a
0 1 2
3 4 5
6 7 8
IDL> a.total(1,/integer)
3 12 21
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| Re: Some IDL_Number documentation quirks [message #93966 is a reply to message #93945] |
Wed, 07 December 2016 14:17  |
chris_torrence@NOSPAM
Messages: 528
Registered: March 2007
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Senior Member |
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On Friday, December 2, 2016 at 12:14:52 PM UTC-7, wlandsman wrote:
> A few quirks in the IDL documentation for IDL_Number
>
> http://www.harrisgeospatial.com/docs/IDL_Number.html
>
> 1. The example for IDL_Number::Median method reads
> *********
> Print the median value of a number:
>
> num = -24601
>
> PRINT, num.Median( )
>
> IDL prints:
>
> 24601
> **********
> Huh? The median of a negative scalar is its absolute value? I then realized that this example is probably an unfinished copy/paste from the IDL_Number:Signum method. But
>
> 2. The example for IDL Number::Signum is incorrect
>
> *********************************
> Print the signum value of a number:
>
> num = -24601
>
> PRINT, num.Signum( )
>
> IDL prints:
>
> 24601
> ***********************************
> This is closer but still incorrect. The value of num.signum() should be -1 (the sign of the number).
>
> 3. The documentation of IDL_Number::Total is incomplete.
>
> **************
> Arguments
>
> None.
> Keywords
>
> None.
> ***********
>
> But in fact, although not documented, the dimension argument and five keywords available to the TOTAL() function are also available to IDL_Number::Total. For example
>
> IDL> a = indgen(3,3)
> IDL> a
> 0 1 2
> 3 4 5
> 6 7 8
> IDL> a.total(1,/integer)
> 3 12 21
Whoops, my bad. Thanks Wayne for catching all of these. They'll be fixed in IDL Next (not 8.6). You can also use the Dimension argument to the IDL_Number::Product method.
Cheers,
Chris
Harris Geospatial Solutions
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| Re: Some IDL_Number documentation quirks [message #93967 is a reply to message #93966] |
Wed, 07 December 2016 16:36 |
penteado
Messages: 866
Registered: February 2018
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Senior Member
Administrator |
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There were also some problems in the documentation for BitGet and BitSet, which Wayne and me talked about in an earlier thread:
https://groups.google.com/d/msg/comp.lang.idl-pvwave/bM6iI_7 Y1mE/f2S0WkJ7AwAJ
On Wednesday, December 7, 2016 at 2:17:16 PM UTC-8, Chris Torrence wrote:
> On Friday, December 2, 2016 at 12:14:52 PM UTC-7, wlandsman wrote:
>> A few quirks in the IDL documentation for IDL_Number
>>
>> http://www.harrisgeospatial.com/docs/IDL_Number.html
>>
>> 1. The example for IDL_Number::Median method reads
>> *********
>> Print the median value of a number:
>>
>> num = -24601
>>
>> PRINT, num.Median( )
>>
>> IDL prints:
>>
>> 24601
>> **********
>> Huh? The median of a negative scalar is its absolute value? I then realized that this example is probably an unfinished copy/paste from the IDL_Number:Signum method. But
>>
>> 2. The example for IDL Number::Signum is incorrect
>>
>> *********************************
>> Print the signum value of a number:
>>
>> num = -24601
>>
>> PRINT, num.Signum( )
>>
>> IDL prints:
>>
>> 24601
>> ***********************************
>> This is closer but still incorrect. The value of num.signum() should be -1 (the sign of the number).
>>
>> 3. The documentation of IDL_Number::Total is incomplete.
>>
>> **************
>> Arguments
>>
>> None.
>> Keywords
>>
>> None.
>> ***********
>>
>> But in fact, although not documented, the dimension argument and five keywords available to the TOTAL() function are also available to IDL_Number::Total. For example
>>
>> IDL> a = indgen(3,3)
>> IDL> a
>> 0 1 2
>> 3 4 5
>> 6 7 8
>> IDL> a.total(1,/integer)
>> 3 12 21
>
> Whoops, my bad. Thanks Wayne for catching all of these. They'll be fixed in IDL Next (not 8.6). You can also use the Dimension argument to the IDL_Number::Product method.
> Cheers,
> Chris
> Harris Geospatial Solutions
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