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Hi Joleen-extractPressureFromNWPGrid just calls DerivedGridFactory.createPressureGridFromDomain. Looking at the code there, I think your grid should be handled okay. What kind of error do you get? You can send that to me off line.
Don On 12/10/13 7:19 AM, Joleen Feltz wrote:
Hi, This question might be out of place, but I have been wondering for a long time how to create a cross section of potential temperature based off a satellite generated temperature and humidity retrieval. I have been able to create a single level flat field, but never a cross section. It seems to me that this is the approach I want to take. However, the field that I have does not appear to be a proper flat field for the extractPressureFromNWPGrid function. What are the requirements? The field as far as I know is T(lon,lat,P): VisAD MathType analysis FunctionType: Domain has 3 components: 0. RealType: longi[unit:degrees_east] 0. Name = longi[unit:degrees_east] 0. Unit: degrees_east 1. RealType: lati[unit:degrees_north] 1. Name = lati[unit:degrees_north] 1. Unit: degrees_north 2. RealType: Plevs[unit:hPa] 2. Name = Plevs[unit:hPa] 2. Unit: hPa Range: RealType: TAir[unit:K] Name = TAir[unit:K] Unit: K Thanks for your help, Joleen On Dec 9, 2013, at 3:59 PM, Paul Graham wrote:Hi Tom, Thanks for your help. I figured out a method after some experimentation and realised I could not use the visad logic. My algorithm works point-wise, which requires having to step through each point individually. Essentially, I modified existing code for substitution, found in IDV's Jython library: def wetbulb(temp,dewpt): from java.lang import Math tempData = temp.clone(); dewptData = dewpt.clone(); presData = extractPressureFromNWPGrid(tempData); wetbulbData = temp.clone(); if (GridUtil.isTimeSequence(tempData)): for t in range(tempData.getDomainSet().getLength()): tempValues = tempData[t] dewptValues = dewptData[t] presValues = presData[t] wetbulbRangeObj = wetbulbData.getSample(t) newValues = wetbulbRangeObj.getFloats(0) print "Processing wetbulb temperature for time ", t for i in range(len(tempValues)): if(str(float(tempValues[i].getValue()))!='nan'): newValues[0][i] = findwetbulb(kelvinToCelcius(tempValues[i].getValue()),kelvinToCelcius(dewptValues[i].getValue()),presData[i].getValue()) wetbulbRangeObj.setSamples(newValues,1) wetbulbData = newUnit(noUnit(wetbulbData),'Wetbulb temperature in celcius','C') return wetbulbData Paul On 10 December 2013 01:12, Tom Whittaker <whittaker@xxxxxxxx> wrote:Hi Paul -- If your function has no logic that needs to be applied to each point, then if the data were read in via the IDV they would be "VisAD Data objects" and you should just be able to do something like: a = b + c - d where "b", "c" and "d" are 3D Data objects (or maybe 4D if they include "time") and it will do the computation on every point. and put the result in "a" (creating a new Data object with characteristics like that of "b" (the first object in the computation). If you have logic, then you might have to iterate over every point...I say "might" because sometimes some of the built-in methods like "mask" can be used to simulate logic. Hope that helps. tom On Sun, Dec 8, 2013 at 9:39 PM, Paul Graham <meteorpaul@xxxxxxxxx> wrote:Hi IDV'ers, I have written a Jython function which takes temperature, dewpoint and pressure as arguments and evaluated at each point in a 3d domain to calculate the wet bulb temperature. What is the best way using Jython to iterate over my domain so I can set the wetbulb result for each point? Eg. wetbulbresult[i][j][k] = findwetbulb(temperature[i][j][k],dewpoint[i][j][k],pressure[i][j][k]), where i,j are subscripts for the latitude and longitude and k for the height. Thanks in advance, Paul _______________________________________________ idvusers mailing list idvusers@xxxxxxxxxxxxxxxx For list information, to unsubscribe, visit:http://www.unidata.ucar.edu/mailing_lists/ -- Tom Whittaker University of Wisconsin-Madison Space Science & Engineering Center (SSEC) Cooperative Institute for Meteorological Satellite Studies (CIMSS) 1225 W. Dayton Street Madison, WI 53706 USA ph: +1 608 262 2759_______________________________________________ idvusers mailing list idvusers@xxxxxxxxxxxxxxxx For list information, to unsubscribe, visit: http://www.unidata.ucar.edu/mailing_lists/_______________________________________________ idvusers mailing list idvusers@xxxxxxxxxxxxxxxx For list information, to unsubscribe, visit: http://www.unidata.ucar.edu/mailing_lists/
-- Don Murray NOAA/ESRL/PSD and CIRES 303-497-3596 http://www.esrl.noaa.gov/psd/people/don.murray/
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