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Re: scalar system variable as single element array [message #80165]

Sun, 13 May 2012 23:31

Mats Löfdahl
Messages: 263
Registered: January 2012

Senior Member

Den söndagen den 13:e maj 2012 kl. 22:00:31 UTC+2 skrev fawltyl...@gmail.com:
> Hi guys,
>
> the IDL help says that a scalar can be considered a single element array. So why is the following expression failing?
>
> IDL> help, !pi[0]
> % Expression must be an array in this context: !PI.
> % Execution halted at: $MAIN$
>
> Is it a bug or feature :-)
>
> regards,
> Lajos

This works with variables but !pi is not a variable. Think of it as a constant, like the number 2:

IDL> a=!pi
IDL> help,2,!pi,a
<Expression> INT = 2
<Expression> FLOAT = 3.14159
A FLOAT = 3.14159
IDL> help,a[0]
<Expression> FLOAT = 3.14159
IDL> help,(2)[0],(!pi)[0]
<Expression> INT = 2
<Expression> FLOAT = 3.14159

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[Message index]

		Re: scalar system variable as single element array By: Mats Löfdahl on Sun, 13 May 2012 23:31
		Re: scalar system variable as single element array By: Lajos Foldy on Sun, 13 May 2012 23:23
		Re: scalar system variable as single element array By: lecacheux.alain on Sun, 13 May 2012 16:58

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