# [gradsusr] Weighting in Ensemble Dimension

Tom Hultquist weathertom at gmail.com
Sun Apr 20 15:23:37 EDT 2014

```Thanks Jeff. I had been doing things "manually" via summing with different weights then dividing to get the average. Was looking to simplify by using the ensemble dimension and built in functions. So, I'll play around with creating a function to vary the weighting.

On April 20, 2014 2:14:25 PM CDT, Jeff Duda <jeffduda319 at gmail.com> wrote:
>Tom,
>
>I think you can create a weighting function and then use it in the
>average
>command.  So it would look like
>
>(define weight field somehow as wgt)
>'d ave(wgt*product,e=1,e=8)'
>
>The tricky part is creating a weighting field that is a function of
>ensemble member.  I haven't tried this to see if it works or not, but
>if
>you set your dimension environment so that ensemble dimension is
>varying,
>you could then try defining the field, possibly using the
>function.  If that doesn't work, you'll have to create a separate
>weight
>function for each ensemble member and display the product using a
>manual
>average, i.e.,
>'define sum = weight1*member1 + weight2*member2 + ... +
>weightN*memberN'
>'define totalweight = weight1+weight2 + ... + weightN'
>'d sum/totalweight'
>
>If you're using a script to do this, the sums can be handled using a
>while
>loop to make them much more tractable.
>
>Good luck. Let me know if you have more questions.
>
>Jeff
>
>
>On Sun, Apr 20, 2014 at 1:24 PM, Tom Hultquist <weathertom at gmail.com>
>wrote:
>
>> Is there a way to adjust the weighting of members when using the
>ensemble
>> dimension? I'd like to use the ave function across and ensemble (e=1,
>e=8),
>> but want different weighting for members 1-4 vs members 5-8.
>>
>> _______________________________________________
>>
>>
>
>
>--
>Jeff Duda
>University of Oklahoma School of Meteorology
>Center for Analysis and Prediction of Storms
>
>
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>
>_______________________________________________