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Re: Excluding Decimal Places in the Values of a Variable [message #83236 is a reply to message #83235]

Thu, 14 February 2013 13:17

Lisa08
Messages: 4
Registered: February 2013

Junior Member

On Thursday, February 14, 2013 2:55:56 PM UTC-6, David Fanning wrote:
> Lisa08 writes:
>
>
>
>>
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>> Hi everyone,
>
>>
>
>> I have a question that I think should be very simple to answer but I can't seem to find a solution for it.
>
>>
>
>> I am trying to chop off the last two decimal places for the values of a variable. The values for my variable have 5 decimal places and I want to trim it down to 3. For example, let's say my variable is:
>
>>
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>> x=[[1.35679, 2.65487], [3.65789, 4.56455]]
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>>
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>> So I want to exclude the last two decimal places and have it be:
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>> x=[[1.356, 2.654], [3.657, 4.564]]
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>> Now, I know how to do this using a "PRINT" command as below but I don't know how to tell IDL to save the output that was printed out to a variable.
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>> IDL> print, x, FORMAT='(F8.3)'
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>> 1.357
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>> 2.655
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>> 3.658
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>>
>
>> Also, Is there a way to make it "not round up"? I have found a routine that does what I want, excludes the final two decimal places and doesn't round up, but the problem with it is that it converts the values to a string to do this and then I can't seem to convert them back to floats as it gives me the following error:
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>>
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>> Type Conversion error: Unable to convert given STRING to Float
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>>
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>> The routine I found online to do this is called DECIMALS.pro and is available here:
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>> https://people.ok.ubc.ca/erosolo/idl/lib/decimals.pro
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> I would do it this way:
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> IDL> x=[[1.35679, 2.65487], [3.65789, 4.56455]]
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> IDL> x = Fix(x*1000)/1000.
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> Cheers,
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> David
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> --
>
> David Fanning, Ph.D.
>
> Fanning Software Consulting, Inc.
>
> Coyote's Guide to IDL Programming: http://www.idlcoyote.com/
>
> Sepore ma de ni thue. ("Perhaps thou speakest truth.")

Wow, so simple and easy. I always make things more complicated than they have to be. Thanks so much!

Lisa

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[Message index]

		Re: Excluding Decimal Places in the Values of a Variable By: Paul Van Delst[1] on Tue, 19 February 2013 12:32
		Re: Excluding Decimal Places in the Values of a Variable By: David Fanning on Thu, 14 February 2013 13:49
		Re: Excluding Decimal Places in the Values of a Variable By: cgguido on Thu, 14 February 2013 13:41
		Re: Excluding Decimal Places in the Values of a Variable By: David Fanning on Thu, 14 February 2013 13:31
		Re: Excluding Decimal Places in the Values of a Variable By: Lisa08 on Thu, 14 February 2013 13:17
		Re: Excluding Decimal Places in the Values of a Variable By: David Fanning on Thu, 14 February 2013 12:55

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