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All Topics | Topic "Warning: extremely large value may cause for lp solver"
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Author Message
Ms. Sultan Kılınç

Subject: Warning: extremely large value may cause for lp solver   
Posted: 10/23/2017 Viewed: 16063 times
I am using the simplified coefficient method in my model. it gives this "warning: This extremely large value (463,613,871,188,160) may cause problems for the linear program (LP) solver. Please check if it is a mistake, or can reasonably be reduced." for the last month of precipitation data for all the catchment nodes.

the warning is given for the last data (last month) of both current accounts year and reference scenario. i tried to change the last value of the csv files but the warning stayed. so, i cannot find the reason. what could be the reason for it? thank you.



Ms. Stephanie Galaitsi

Subject: Re: Warning: extremely large value may cause for lp solver   
Posted: 10/25/2017 Viewed: 15976 times
Hi Sultan,

When you enter the data for using the ReadFromFile wizard, does the chart in the data view show reasonable values, or does it show the very high values?

Ms. Sultan Kılınç

Subject: Re: Warning: extremely large value may cause for lp solver   
Posted: 11/6/2017 Viewed: 15870 times
Hi Stephanie,

The chart shows the exact values i entered. they are not high.

Also, the interesting thing is that the warning directs me to the precipitation data only, it is not shown for evapotranspiration data.
Ms. Stephanie Galaitsi

Subject: Re: Warning: extremely large value may cause for lp solver   
Posted: 11/6/2017 Viewed: 15861 times
Very curious. Can you email me the CSV file?
Ms. Sultan Kılınç

Subject: Re: Warning: extremely large value may cause for lp solver   
Posted: 11/6/2017 Viewed: 15855 times
sure, i had sent now. please check
Ms. Stephanie Galaitsi

Subject: Re: Warning: extremely large value may cause for lp solver   
Posted: 11/7/2017 Viewed: 15849 times
To anyone else reading, it was a units problem. One easy mistake to make in modeling is using spreadsheet data with one unit to enter data in the model that is specified for another unit. The best ways to avoid this is to check your units, and always document your spreadsheets.

You can also change default units in WEAP by going to General/Units, but if course there are limitations. For something like precipitation (default mm), you will need to use a 1-dimensional measurement, because anything measuring area or volume will not work with WEAP's equations.
Topic "Warning: extremely large value may cause for lp solver"