[gradsusr] How to define this formula?

T. haghroosta haghroosta at hotmail.com
Sun Feb 3 13:14:31 EST 2013


Dear Jeff Duda, I did your suggestion as follows. As an extra explanation, I would like to calculate RMSE for a special parameter like TK during four days in a special Lon and Lat. I also have two files, observed and simulated. So, I wrote this script, but it didn't work. Could you please help me? Another question how can I show the last output (RMSE)?  t=1
pow=0
'reinit'
while(t<=4)
'sdfopen observed.nc'
lon= 100
lat= 21
TK1=TK
'close 1'
'open simulated.ctl'
TK2=TK
'pow1=pow(TK1(t)-TK2(t))
'pow = pow + pow1
t=t+1
endwhile
'RMSE= sqrt(pow/t)'

 Regards, T.  
> 
> Today's Topics:
> 
>    1. How to define this formula? (T. haghroosta)
>    2. Re: How to define this formula? (Jeff Duda)
>    3. Re: lon lat to km (wendi harjupa)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Sun, 3 Feb 2013 05:24:48 +0000
> From: "T. haghroosta" <haghroosta at hotmail.com>
> Subject: [gradsusr] How to define this formula?
> To: <gradsusr at gradsusr.org>
> Message-ID: <DUB121-W214D8BDEBA3D102D60AD37DD020 at phx.gbl>
> Content-Type: text/plain; charset="windows-1256"
> 
> 
> 
> 
> 
> Dear All, Could you please tell me how can I define this equation which I have attached to the email. I got confused completely, I did somethings that don't work. 
> 
> Regards, T.
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> ------------------------------
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> Message: 2
> Date: Sun, 3 Feb 2013 01:53:22 -0600
> From: Jeff Duda <jeffduda319 at gmail.com>
> Subject: Re: [gradsusr] How to define this formula?
> To: GrADS Users Forum <gradsusr at gradsusr.org>
> Message-ID:
> 	<CAAig09DhORYVv_MLG58R5SEAv9pypU41igt_7XwYt97v9Ljocw at mail.gmail.com>
> Content-Type: text/plain; charset="iso-8859-1"
> 
> That looks like standard deviation or RMSE.  Either way, assume your array
> is VAR.  Then it's
> 
> C = sqrt(amean(asum(pow(VAR -
> amean(VAR,x=x1,x=x2,y=y1,y=y2)),2),x=x1,x=x2,y=y1,y=y2))
> 
> OR
> 
> C = sqrt(asum(VAR - amean(VAR,x=x1,x=x2,y=y1,y=y2))/N), where N is the
> number of grid points over which you're summing.
> 
> You'll have to insert values for x1, x2, y1, and y2 yourself.  You can use
> lat and lon instead of y and x, though.
> 
> If that fails, try breaking it into parts:
> 'average = amean(VAR,x=x1,x=x2,y=y1,y=y2)'
> 'diffsquaredsum = asum(pow(VAR-average,2),x=x1,x=x2,y=y1,y=y2)'
> 'SD (or) RMSE = sqrt(diffsquaredsum/N)'
> 
> Jeff Duda
> 
> On Sat, Feb 2, 2013 at 11:24 PM, T. haghroosta <haghroosta at hotmail.com>wrote:
> 
> >  Dear All,
> >
> > Could you please tell me how can I define this equation which I have
> > attached to the email. I got confused completely, I did somethings that
> > don't work.
> >
> > Regards,
> >
> > T.
> >
> > **** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **************************
> > ** **** ********
> >
> > _______________________________________________
> > gradsusr mailing list
> > gradsusr at gradsusr.org
> > http://gradsusr.org/mailman/listinfo/gradsusr
> >
> >
> 
> 
> -- 
> Jeff Duda
> Graduate research assistant
> University of Oklahoma School of Meteorology
> Center for Analysis and Prediction of Storms
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> ------------------------------
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> Message: 3
> Date: Sun, 3 Feb 2013 21:55:53 +0900
> From: wendi harjupa <wendiharjupa at gmail.com>
> Subject: Re: [gradsusr] lon lat to km
> To: GrADS Users Forum <gradsusr at gradsusr.org>
> Message-ID:
> 	<CA+u6P9METKDdi6QQkH-FZT7mMzcFSAR17MeuvY-hiOkwYQn6Ow at mail.gmail.com>
> Content-Type: text/plain; charset="iso-8859-1"
> 
> Dear Mr.  Jeff
> 
> Thank you very much for your guidance as far..
> But, I am very sorry for asking you many times..
> since it is very difficult for me..
> 
> I tried to change some parts of script, but still this did not run..
> I got error message as below :
> 
> Error from CDIFF:  Specified dimension non varying
> Operation Error:  Error from cdiff function
>   Error ocurred at column 31
> DEFINE error:  Invalid expression.
> *** glibc detected *** grads: corrupted double-linked list: 0x089e2918
> ***
> Would you mind to explain more??
> 
> Thank you very much
> 
> Best regards,
> wendi
> 
> On Sun, Feb 3, 2013 at 1:46 AM, Jeff Duda <jeffduda319 at gmail.com> wrote:
> 
> > Use this code:
> >
> > 'reinit'
> > 'open try2.ctl'
> > 'set grads off'
> > 'set mproj latlon'
> > 'set mpdset hires'
> > 'set gxout shaded'
> > 'set grid on'
> > 'set lon 100  101'
> > 'set lat -1  0'
> > 'define dx = *6.371e3**cos(-1*(3.14159/180))*cdiff(100,0)*(3.14159/180)'
> > 'define dy = *6.371e3**cdiff(-1,0)*(3.14159/180))'
> > 'define xdist = ((lon-100)/0.004492369)*(dx/2)'
> > 'define ydist = ((lat-0)/0.004522556)*(dy/2)'
> > 'set z 5'
> > 'set t 1'
> > 'd ref'
> >
> > The square brackets were just to show different groupings.  When it comes
> > time to code it, you must use only parentheses.
> >
> > The above should work.
> >
> > Jeff
> >
> > On Sat, Feb 2, 2013 at 1:41 AM, wendi harjupa <wendiharjupa at gmail.com>wrote:
> >
> >> Dear Mr. Jeff
> >>
> >> Thank you very much for your explanation,
> >> but I am very sorry, I still do not get it,
> >>
> >> I made new script
> >>
> >> 'reinit'
> >> 'open try2.ctl'
> >> 'set grads off'
> >> 'set mproj latlon'
> >> 'set mpdset hires'
> >> 'set gxout shaded'
> >> 'set grid on'
> >> 'set lon 100  101'
> >> 'set lat -1  0'
> >> 'define dx = *6.371e3**cos(-1*(3.14159/180))*cdiff(100,0)*(3.14159/180)'
> >> 'define dy = *6.371e3**cdiff(-1,0)*(3.14159/180))'
> >> 'define xdist = ((lon-100)/0.004492369)*(dx/2]'
> >> 'define ydist = ((lat-0)/0.004522556)*dy/2]'
> >> 'set z 5'
> >> 'set t 1'
> >> 'd ref'
> >>
> >> I checked grads document and I found that 6.371e3 is radius of the earth
> >> (6371 to 6374 km)*.*
> >> *
> >> *
> >> *I tried to change "*6.371e3" to "0e10" which is mean 0 to 10 km)
> >> But still the program did not run normally.
> >>
> >> I changed the value of lon and lat in script with 100 and -1.
> >> but still I got error.
> >>
> >> Please help me to solve it.
> >>
> >> Thank you very much
> >> Best regards,
> >> wendi
> >>
> >> On Sat, Feb 2, 2013 at 2:21 AM, Jeff Duda <jeffduda319 at gmail.com> wrote:
> >>
> >>> Wendi,
> >>> You need to run those two define commands at the top of my previous
> >>> email before attempting to define the xdist and ydist fields.  Also, since
> >>> I can see your control file information, I can see that dlon is 0.004492369
> >>> and dlat is  0.004522556.  So substitute those two values into your
> >>> expressions for xdist and ydist also.
> >>>
> >>> Jeff
> >>>
> >>>
> >>> On Fri, Feb 1, 2013 at 4:36 AM, wendi harjupa <wendiharjupa at gmail.com>wrote:
> >>>
> >>>> Dear Mr. Jeff
> >>>>
> >>>> I have tried to use the scipt which you suggested,
> >>>> But, still I could not do it. Would you help me more...
> >>>>
> >>>> here I send my gs file :
> >>>>
> >>>>  'reinit'
> >>>> 'open try2.ctl'
> >>>> 'set grads off'
> >>>> 'set mproj latlon'
> >>>> 'set mpdset hires'
> >>>> 'set gxout shaded'
> >>>> 'set grid on'
> >>>> 'set lon 100  101'
> >>>> 'set lat 0  1'
> >>>> 'define xdist = [(lon 99.7)/dlon]*[dx/2]'
> >>>> 'define ydist = [(lat -1.02)/dlat]*[dy/2]'
> >>>> 'set z 5'
> >>>> 'set t 1'
> >>>> 'd ref'
> >>>>
> >>>> Below is my ctl file :
> >>>>
> >>>> DSET 1013.dat
> >>>> TITLE  RADAR
> >>>> OPTIONS  TEMPLATE LITTLE_ENDIAN
> >>>> UNDEF  -1000
> >>>> XDEF    321 LINEAR    99.688120996    0.004492369
> >>>> YDEF    321 LINEAR    -1.083708891    0.004522556
> >>>> ZDEF    39  LINEAR   1.0 0.5
> >>>> TDEF    15 LINEAR 13:00Z10apr2004  4mn
> >>>> VARS    2
> >>>> ref 39  99  Reflectivity(dBZ)
> >>>> vel 39  99  Doppler Velocity(m/s)
> >>>> ENDVARS
> >>>>
> >>>>
> >>>> Would you check my gs file, is there something that I have to revise??
> >>>>
> >>>> Thank you very much.
> >>>>
> >>>> Best regards,
> >>>> wendi
> >>>>
> >>>>
> >>>>
> >>>> On Fri, Feb 1, 2013 at 10:34 AM, Jeff Duda <jeffduda319 at gmail.com>wrote:
> >>>>
> >>>>> These commands will help.
> >>>>>
> >>>>> 'define dx = 6.371e3*cos(lat*(3.14159/180))*cdiff(lon,x)*(3.14159/180)'
> >>>>> 'define dy = 6.371e3*cdiff(lat,y)*(3.14159/180))'
> >>>>>
> >>>>> They define grid increments in terms of spatial distance rather than
> >>>>> geographic distance.  If you're trying to change the axes and tick marks,
> >>>>> you'll have to define an origin and define your x and y distances based on
> >>>>> that.  For instance, if you set your lower left domain corner (latitude 0
> >>>>> and longitude 100), then you can define your coordinate distances using
> >>>>>
> >>>>> 'define xdist = [(lon-100)/dlon]*[dx/2]'
> >>>>> 'define ydist = [(lat-0)/dlat]*[dy/2]'
> >>>>>
> >>>>> I think this should work, but I haven't tested it myself, so I don't
> >>>>> know.  dlon and dlat are the step values from the XDEF and YDEF lines of
> >>>>> the control file, respectively.
> >>>>>
> >>>>> Jeff Duda
> >>>>>
> >>>>> On Thu, Jan 31, 2013 at 7:02 AM, wendi harjupa <wendiharjupa at gmail.com
> >>>>> > wrote:
> >>>>>
> >>>>>> Dear Sir/Madam
> >>>>>>
> >>>>>> I need help
> >>>>>> I have problem with grads command,
> >>>>>> I am not well understand with command gr2XY,
> >>>>>>
> >>>>>> Actually I want to convert the lon 100  to 101, and lat 0 to 1 to
> >>>>>> distance (km)
> >>>>>> let think that lon 100 is 0 km, and lat 0 is 0 km,
> >>>>>>
> >>>>>> what command I can use to convert lon and lat to km?
> >>>>>>
> >>>>>> Thank you very much for your help
> >>>>>>
> >>>>>> best regards,
> >>>>>> --
> >>>>>> -------------
> >>>>>> Wendi Harjupa. ST
> >>>>>> Shimane University Graduate School of Engineering Sciences
> >>>>>> Department of Electronic Control Systems
> >>>>>> Remote Sensing Laboratory
> >>>>>> s119447
> >>>>>> Cellphone : +81-080-4268-6676
> >>>>>> email : wendi at rslab.riko.shimane-u.ac.jp
> >>>>>>
> >>>>>> _______________________________________________
> >>>>>> gradsusr mailing list
> >>>>>> gradsusr at gradsusr.org
> >>>>>> http://gradsusr.org/mailman/listinfo/gradsusr
> >>>>>>
> >>>>>>
> >>>>>
> >>>>>
> >>>>> --
> >>>>> Jeff Duda
> >>>>> Graduate research assistant
> >>>>> University of Oklahoma School of Meteorology
> >>>>> Center for Analysis and Prediction of Storms
> >>>>>
> >>>>> _______________________________________________
> >>>>> gradsusr mailing list
> >>>>> gradsusr at gradsusr.org
> >>>>> http://gradsusr.org/mailman/listinfo/gradsusr
> >>>>>
> >>>>>
> >>>>
> >>>>
> >>>> --
> >>>> -------------
> >>>> Wendi Harjupa. ST
> >>>> Shimane University Graduate School of Engineering Sciences
> >>>> Department of Electronic Control Systems
> >>>> Remote Sensing Laboratory
> >>>> s119447
> >>>> Cellphone : +81-080-4268-6676
> >>>> email : wendi at rslab.riko.shimane-u.ac.jp
> >>>>
> >>>> _______________________________________________
> >>>> gradsusr mailing list
> >>>> gradsusr at gradsusr.org
> >>>> http://gradsusr.org/mailman/listinfo/gradsusr
> >>>>
> >>>>
> >>>
> >>>
> >>> --
> >>> Jeff Duda
> >>> Graduate research assistant
> >>> University of Oklahoma School of Meteorology
> >>> Center for Analysis and Prediction of Storms
> >>>
> >>> _______________________________________________
> >>> gradsusr mailing list
> >>> gradsusr at gradsusr.org
> >>> http://gradsusr.org/mailman/listinfo/gradsusr
> >>>
> >>>
> >>
> >>
> >> --
> >> -------------
> >> Wendi Harjupa. ST
> >> Shimane University Graduate School of Engineering Sciences
> >> Department of Electronic Control Systems
> >> Remote Sensing Laboratory
> >> s119447
> >> Cellphone : +81-080-4268-6676
> >> email : wendi at rslab.riko.shimane-u.ac.jp
> >>
> >> _______________________________________________
> >> gradsusr mailing list
> >> gradsusr at gradsusr.org
> >> http://gradsusr.org/mailman/listinfo/gradsusr
> >>
> >>
> >
> >
> > --
> > Jeff Duda
> > Graduate research assistant
> > University of Oklahoma School of Meteorology
> > Center for Analysis and Prediction of Storms
> >
> > _______________________________________________
> > gradsusr mailing list
> > gradsusr at gradsusr.org
> > http://gradsusr.org/mailman/listinfo/gradsusr
> >
> >
> 
> 
> -- 
> -------------
> Wendi Harjupa. ST
> Shimane University Graduate School of Engineering Sciences
> Department of Electronic Control Systems
> Remote Sensing Laboratory
> s119447
> Cellphone : +81-080-4268-6676
> email : wendi at rslab.riko.shimane-u.ac.jp
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> End of gradsusr Digest, Vol 36, Issue 8
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