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
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> 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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