[gradsusr] Warning from LOG10: Data has 182085 values <= zero

[Perry, Aaron]

Good Afternoon All,

I am trying to use a formula to convert some data in GrADS v2.2.1.

Excel Formula:
=10*LOG10(200*RainfallRate^1.6)

GrADS Formula (Broken down step-by-step for troubleshooting):
'define pratemmhr = (PRATEsfc.1*3600.0)' *converting mm/sec to mm/hour
'define step1 = pow(pratemmhr,1.6)'
'define step2 = (200.0*step1)'
'define step3 = log10(const(step2,0,-u))'
'define step4 = (10.0*step3)'
'define prate2dbz = step4'

I am receiving the following error in my Linux terminal:

Warning from LOG10:  Data has 182085 values <= zero
These were set to the undefined value

What's going wrong here?

*Note, in Step 3, I have attempted to convert all undefined values to zeroes while log10() is called upon.

Best,

Aaron Perry
Meteorologist
Class of '16
Northern Vermont University-Lyndon
(formerly Lyndon State College)
Boston, Mass.
Twitter: @AaronPerryWx<https://twitter.com/AaronPerryWx><https://twitter.com/arnpry><https://twitter.com/AaronPerryWx>
Email: Aaron.Perry at lyndonstate.edu<http://Aaron.Perry@lyndonstate.edu/>
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