[gradsusr] lon lat to km

Jeff Duda jeffduda319 at gmail.com
Mon Feb 4 12:30:34 EST 2013 

Don't change these four statements from what I have suggested:
'define dx = *6.371e3**cos(-1*(3.14159/180))*cdiff(lon,x)*(3.14159/180)'
'define dy = *6.371e3**cdiff(lat,y)*(3.14159/180))'
'define xdist = ((lon-100)/0.004492369)*(dx/2)'
'define ydist = ((lat-0)/0.004522556)*(dy/2)'

In the definitions of dx and dy, the grids lon and lat, and dimension
expressions x and y must be entered exactly as that.  Do not replace any of
those values with anything else.  The rest is fine.

Jeff

On Mon, Feb 4, 2013 at 1:49 AM, wendi harjupa <wendiharjupa at gmail.com>wrote:

> Dear Mr Jeff
>
> Thank you very much for your guidance
>
> Here the 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'
>
> The script is similar with the script that you suggested.
> But, I tried to make changes in many points
>
> for example :
>
> '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 = ((100 - 101)/0.004492369)*(dx/2)'
> 'define ydist = ((-1-0)/0.004522556)*(dy/2)'
>
> or I tried to make plot
>
> 'd xdist'
>
> But, always I got error message.
>
> Please teach me more.
>
> Best regards,
> wendi
>
>
> On Mon, Feb 4, 2013 at 3:25 AM, Jeff Duda <jeffduda319 at gmail.com> wrote:
>
>> 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
>>
>> _______________________________________________
>> 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/20130204/7b19281b/attachment-0003.html

More information about the gradsusr mailing list