[gradsusr] Help with Isentropic Potential Vorticity (IPV) SCRIPT

[Arturo]

Hi all,
I´m having some problems with my VPI script:
______________________________________________________________________
'set t 1'
'set lev 1000 10'
'define coriol=2*7.29e-5*sin(lat*3.1415/180)'
'define dudy=cdiff(ugrdprs,y)/(111177*cdiff(lat,y))'
'define dvdx=cdiff(vgrdprs,x)/(111177*cdiff(lon,x)*cos(lat*3.1415/180))'
'define dt=tmpprs(z-1)*pow(1000/lev(z-1),0.286)-tmpprs(z+1)*pow(1000/lev(z+1),0.286)'
'define dp=100*(lev(z-1)-lev(z+1))'
'define dtdp=dt/dp'
"define part1="isen(dudy,tmpprs,lev,320)

"define part2="isen(dvdx,tmpprs,lev,320)
"define part3="isen(dtdp,tmpprs,lev,320)
'set z 1'

'set lat -30'
'set lon -110 -60'
'define pv320=-9.8*(coriol+part1-part2)*part3'

'color -15 -1.5 1.5 kind mediumblue->royalblue->paleturquoise->white'

'set mpdset hires'

'set display color white'
'd pv320*1e6'

-----------------------------------------------------------------------------------------------------------------------------
  When i run my "prueba7.gs"  in the GRADS i have the following error:
______________________________________________________________________
ga-> open forecast.ctl 
Scanning description file:  forecast.ctl
Data file C:\OpenGrADS\Contents\Cygwin\Versions\2.0.1.oga.1\i686\automatico\gfs.t12z.pgrb2f%f2 is open as file 1
LON set to 0 360
LAT set to -90 90
LEV set to 1000 1000
Time values set: 2013:11:24:12 2013:11:24:12
E set to 1 1
ga-> prueba7
Data Request Warning:  Request is completely outside file limits
Data Request Warning:  Request is completely outside file limits
Function not found: isen
  Error occurred on line 22
  In file prueba7.gs
______________________________________________________________________


But i have the "isen.gs" in the GRADS directory but i dont know why it doesn´t reconize the function, i downloaded the isen.gs from this page ftp://cola.gmu.edu/grads/scripts/isen.gs

Also i dont know why the warning "DATA REQUEST WARNING ...... ", i dont know what does it means .


If anyone can help, i would be very gratefull


Guisseppe Vasquez V
Meteorologic student

UNALM - Lima - Peru
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://gradsusr.org/pipermail/gradsusr/attachments/20131127/f399ed84/attachment.html