[gradsusr] lon lat to km

[Jeff Duda]

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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://gradsusr.org/pipermail/gradsusr/attachments/20130201/54c06c40/attachment-0003.html