[gradsusr] How to convert a string to a real number?
Jeffrey Duda
jdduda at iastate.edu
Thu Jan 6 00:44:25 EST 2011
Qinglan,
I'm running 2.0.a9: Config: v2.0.a9 little-endian readline printim grib2
netcdf hdf4-sds hdf5 opendap-grids,stn geotiff shapefile
I don't get an error when I run the script, so perhaps it is due to the
version you are using or some libraries. I don't have the knowledge of
computer architecture to know how to fix that other than suggest you update
to the newest version. Sorry.
Jeff
On Wed, Jan 5, 2011 at 7:56 PM, qinglan <qinglan at hku.hk> wrote:
> Dear Jeff,
>
> Yes, SW2=SW1+1=396.505 is exactly what I want. I just want to make sure
> that SW1 is a single value that can be used for summation.
>
> I changed the line: SW1=subwrd(SWDOWN,1)
>
> to
>
> SW1=subwrd(result,4) , please see the attachment
>
> However, I still get error information:
>
> Syntax Error
>
> Error occurred on line 9
>
> In file try_loop_p2.gs
>
> By the way, my grads is version: v2.0.a3 little-endian readline printim
> grib2 netcdf hdf4-sds
>
>
>
> Thank you very much!
>
> Qinglan Li
>
> ------------------------------
> *From:* gradsusr-bounces at gradsusr.org [gradsusr-bounces at gradsusr.org] On
> Behalf Of Jeffrey Duda [jdduda at iastate.edu]
> *Sent:* Thursday, January 06, 2011 3:44 AM
>
> *To:* GrADS Users Forum
> *Subject:* Re: [gradsusr] How to convert a string to a real number?
>
> Qinglan,
> In your script, try_loop_p2.gs, change the line
>
> SW1=subwrd(SWDOWN.1,1)
>
> to
>
> SW1=subwrd(result,4)
>
> That fixes the errors on lines 9 and 12.
>
> I get two text files, SW1.txt and SW2.txt. SW1.txt contains the single
> value 359.505. SW2.txt contains the single value 360.505. Is this what you
> want?
>
> Jeff
>
> On Wed, Jan 5, 2011 at 8:39 AM, qinglan <qinglan at hku.hk> wrote:
>
>> Dear Jeff and other Grads users,
>>
>> First of all, really appreciate your help and time.
>>
>> In order to make my question more clearly and simple, I have reduced the
>> data size and simplified the code. I attach the .dat file, .ctl file and .gs
>> file, as well as fprintf.gs file. There is no problem running the
>> attached try_loop_p2.gs. The output SW1.txt is 359.505, which should be a
>> string, not a value. My problem is how to transfer SW1 to a number.
>>
>> Still in try_loop_p2.gs, if remove the first * marks in lines 9 and 12
>> (or lines 10 and 13), error occurs. The error information is “Syntax Error”
>> or “Non-numeric args to numeric operation ”.
>>
>> My problem is how to make SW2=SW1+1/ or SW3=SWDOWN+1 work.
>>
>> Thank you very much!
>>
>> Qinglan Li
>>
>> ------------------------------
>> *From:* gradsusr-bounces at gradsusr.org [gradsusr-bounces at gradsusr.org] On
>> Behalf Of Jeffrey Duda [jdduda at iastate.edu]
>> *Sent:* Wednesday, January 05, 2011 1:46 PM
>>
>> *To:* GrADS Users Forum
>> *Subject:* Re: [gradsusr] How to convert a string to a real number?
>>
>> Qinglan,
>> Are you sure you're using the subwrd function correctly? I don't think
>> you are. If you want to get the value of SWDOWN.1 and SWDOWN.2, do
>> something like
>>
>> (set environment commands)
>> 'd SWDOWN.1'
>> SW1 = subwrd(result,1) !make sure this is the correct one...depending on
>> how your control file is setup, you might get "Notice: interpolation will be
>> made", then the value, in which case you'll need to do a sublin command
>> first, then the subwrd command
>>
>> I'm pretty sure that's the source of your error. Here's an example from
>> another script I use (vgeo.gs):
>>
>> 'q dims'
>> xline=sublin(result,2)
>> xdim1=subwrd(xline,11)
>> xdim2=subwrd(xline,13)
>> yline=sublin(result,3)
>> ydim1=subwrd(yline,11)
>> ydim2=subwrd(yline,13)
>> ...
>> ...
>> ...
>> x3 = xdim1 + xdim2
>> say xdim1 "+" xdim2 "=" x3
>> ...
>> ...
>>
>> *The output is:*
>> ga-> run vgeo.gs
>> 1+301=302
>>
>> Try making those changes and see if it works then.
>>
>> Jeff
>>
>> P.S. Alternately, you can try using the maskout function to define a new
>> variable for SWDOWN which is undefined where your LU_index variable is 1.
>> Such a command could be like:
>> 'define SWDOWNmask = maskout(SWDOWN.1,LU_index - 1.5)'
>> This would make sure not to mask out SWDOWN.1 when LU_index was 2 or
>> greater (I'm assuming the values of LU_index are positive integers only).
>>
>>
>> On Tue, Jan 4, 2011 at 9:19 PM, qinglan <qinglan at hku.hk> wrote:
>>
>>> Dear all,
>>>
>>> Thanks for the response, but the reply has not solved my problem. Let me
>>> make my question more specific. I would like to calculate the average of the
>>> SWDOWN (short wave radiation) over certain land type, here referring to
>>> rural land type (LU_index =not 1).
>>>
>>> The following is my original code. First of all, I want summate all the
>>> values of SWDOWN for all the grids with LU_index!=1 and LU_index!=1, then
>>> divided by the total number of nrr. tim, m and n might be larger, here
>>> for simplifying purpose, setting them for only one loop each.
>>>
>>> The problem is the outputs of SWDOWN.1 or SWDOWN.2 are not a single
>>> value, the program treat SWDOWN.1 as a vector, even the t, x, y (tim, m, n)
>>> are fixed to one value.
>>>
>>> Firstly, there is an error for this sentence
>>>
>>> SWDOWN_nrr1=SWDOWN_nrr1+SWDOWN.1
>>>
>>> Or I try to output SWDOWN.1 to a single value
>>>
>>> SW1=subwrd(SWDOWN.1,1)
>>>
>>> the program treats SW1 as a string, not a value, so
>>>
>>> SW5=SW1+SW2 makes mistakes, as well as
>>> SWDOWN_nrr1=SWDOWN_nrr1+'SW1'
>>>
>>> Possible solutions for my problems are: convert the output of SWDOWN.1
>>> to a single value, which I can use for summation. SWDOWN_nrr1=SWDOWN_nrr1+SWDOWN.1;
>>>
>>>
>>> or convert a string to a value, which I can also use it for summation.
>>> SWDOWN_nrr1=SWDOWN_nrr1+'SW1'
>>>
>>>
>>>
>>> Thank you very much!
>>>
>>> Qinglan Li
>>>
>>>
>>>
>>>
>>>
>>> 'reinit'
>>>
>>> 'open Small_Nest3_Moisture_2000July23-27_00_UTC_2000_land_AH100.ctl'
>>>
>>> 'open
>>> Small_Nest3_Moisture_2000July23-27_00_UTC_1980_land_AH100_changed_0.7profile.ctl'
>>>
>>> tim=25
>>>
>>> while(tim<=25)
>>>
>>> SWDOWN_rr1=0
>>>
>>> SWDOWN_rr2=0
>>>
>>> 'set t 'tim''
>>>
>>> nrr=0
>>>
>>> SWDOWN_nrr1=0
>>>
>>> SWDOWN_nrr2=0
>>>
>>> m=1
>>>
>>> while(m<=1)
>>>
>>> n=1
>>>
>>> while(n<=1)
>>>
>>> 'set x 'm''
>>>
>>> 'set y 'n''
>>>
>>> LU1=LU_index.1
>>>
>>> LU2=LU_index.2
>>>
>>> SW1=subwrd(SWDOWN.1,1)
>>>
>>> SW2=subwrd(SWDOWN.2,1)
>>>
>>> SW5=SW1+SW2 ********error
>>>
>>> SW3=1.1
>>>
>>> SW4=2.2
>>>
>>> if (LU1!=1 & LU2!=1)
>>>
>>> nrr=nrr+1
>>>
>>> SWDOWN_nrr1=SWDOWN_nrr1+'SW1' ******error
>>>
>>> SWDOWN_nrr2=SWDOWN_nrr2+'SW2' ******error
>>>
>>> endif
>>>
>>> n=n+1
>>>
>>> endwhile
>>>
>>> m=m+1
>>>
>>> endwhile
>>>
>>> SWDOWN_rr1=SWDOWN_nrr1/nrr
>>>
>>> SWDOWN_rr2=SWDOWN_nrr2/nrr
>>>
>>> *'d SWDOWN_rr1'
>>>
>>> *'d SWDOWN_rr2'
>>>
>>> 'd 'SWDOWN_nrr1''
>>>
>>> 'd 'SWDOWN_nrr2''
>>>
>>> 'fprintf 'LU1' LU1.txt'
>>>
>>> 'd 'LU2''
>>>
>>> 'fprintf 'SW1' SW1.txt'
>>>
>>> 'fprintf 'SW5' SW5.txt'
>>>
>>> 'fprintf 'nrr' nrr.txt'
>>>
>>> 'fprintf 'SWDOWN_nrr2' SWDOWN_nrr2.txt'
>>>
>>> tim=tim+1
>>>
>>> endwhile
>>>
>>> ------------------------------
>>> *From:* gradsusr-bounces at gradsusr.org [gradsusr-bounces at gradsusr.org] On
>>> Behalf Of Jeffrey Duda [jdduda at iastate.edu]
>>> *Sent:* Wednesday, January 05, 2011 3:34 AM
>>> *To:* GrADS Users Forum
>>> *Subject:* Re: [gradsusr] How to convert a string to a real number?
>>>
>>> As far as I'm aware, you shouldn't have to explicitly convert in
>>> grads scripting. Just use your quotes correctly. Here's an example from a
>>> script I wrote to compute theta-e:
>>>
>>> These constants are set as variables within the grads script only (i.e.,
>>> they don't exist in the command window...I can't display Rv or Rd etc.).
>>> Thus they're regarded as constants or strings.
>>>
>>> Rv = 461.5
>>> Rd = 287.05
>>> Cp = 1005
>>> lv = 2.5e6
>>>
>>> In the actual theta-e computation below, notice how the variables are
>>> used between single quotes so as not to be a part of a command that would
>>> otherwise be issued in the command window. This is all you should have to
>>> do to use a string as a number or vice versa.
>>>
>>> 'tempK = tc + 273'
>>> 'es = 6.11*exp((2.5e6/461.5)*((1/273) - (1/tempK)))'
>>> 'e = qvapor*((p+pb)/100) / (qvapor + 0.622)'
>>> 'equivt = tempK + 'Lv'*qvapor/'Cp'
>>> 'thetae = equivt*pow(1000/slp,'Rd'/'Cp')'
>>>
>>>
>>> I hope this helps, but ask more questions if it doesn't.
>>>
>>> Jeff Duda
>>>
>>> On Tue, Jan 4, 2011 at 1:24 PM, Murphy, Darren W <dwmurphy at nps.edu>wrote:
>>>
>>>> I’d like to second this question. I am having the same issue. I think
>>>> the Grads literature says that some commands can use a number as a string
>>>> for calculations. However, when I try and use my number “string” in a max
>>>> or min Grads function, it throws an error.
>>>>
>>>> Thanks,
>>>> Darren
>>>>
>>>>
>>>> On 1/4/11 6:45 AM, "qinglan" <qinglan at hku.hk> wrote:
>>>>
>>>> Dear All,
>>>>
>>>> Is there anybody know how to convert a string to a real number in Grads?
>>>> For example, if my string is ‘300.5’, I want to get the value of 300.5,
>>>> which is a real number, how to do that?
>>>>
>>>> Really appreciate your help!
>>>> Best regards,
>>>> Qinglan Li
>>>>
>>>>
>>>> ------------------------------
>>>> _______________________________________________
>>>> gradsusr mailing list
>>>> gradsusr at gradsusr.org
>>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>>
>>>>
>>>> _______________________________________________
>>>> gradsusr mailing list
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>>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>>
>>>>
>>>
>>>
>>> --
>>> Jeff Duda
>>> Iowa State University
>>> Meteorology Graduate Student
>>> 3134 Agronomy Hall
>>> www.meteor.iastate.edu/~jdduda <http://www.meteor.iastate.edu/%7Ejdduda>
>>>
>>> _______________________________________________
>>> gradsusr mailing list
>>> gradsusr at gradsusr.org
>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>
>>>
>>
>>
>> --
>> Jeff Duda
>> Iowa State University
>> Meteorology Graduate Student
>> 3134 Agronomy Hall
>> www.meteor.iastate.edu/~jdduda <http://www.meteor.iastate.edu/%7Ejdduda>
>>
>> _______________________________________________
>> gradsusr mailing list
>> gradsusr at gradsusr.org
>> http://gradsusr.org/mailman/listinfo/gradsusr
>>
>>
>
>
> --
> Jeff Duda
> Iowa State University
> Meteorology Graduate Student
> 3134 Agronomy Hall
> www.meteor.iastate.edu/~jdduda <http://www.meteor.iastate.edu/%7Ejdduda>
>
> _______________________________________________
> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr
>
>
--
Jeff Duda
Iowa State University
Meteorology Graduate Student
3134 Agronomy Hall
www.meteor.iastate.edu/~jdduda
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