[gradsusr] lon lat to km

Jeff Duda jeffduda319 at gmail.com
Sun Feb 3 13:25:07 EST 2013


What does your script look like now?

Jeff

On Sun, Feb 3, 2013 at 6:55 AM, wendi harjupa <wendiharjupa at gmail.com>wrote:

> 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
>
> _______________________________________________
> 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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