[gradsusr] plotting problem

[Charles Seman]

Frankq,

Don't know if you've found a solution yet? One idea is to try 
ftp://grads.iges.org/grads/examples/xyplot.gs which does a plot of "y" 
vs. "x"

Chuck

frankq wrote:
> Greetings All,
>
> I would be very grateful if anyone could assist with the following 
> problem. It essentially boils down to plotting a list of (user 
> generated) values on a line graph. The background to the problem is as 
> follows:
>
> * We use WRF to generate forecasts (6 days ahead) of temp, wind speed, 
> rel. hum ...
> * We calculate a heat load index (as well an "integrated" heat load - if 
> you could call it that) on an hourly basis. The expressions include 
> sqrt's, logs, exp's, consequently situations like sqrt(Temp) where Temp 
> < 0 have to be handled.
>
> The approach we have taken is as follows:
>
> * Extract a time series of all required variables
> * Import some initialisations/coefficients from a file
> * Perform all calculations
> * Write results to an ascii output file
> * Plot results on a graph.
>
> It all works except for the plotting bit. Below is the skeleton of the 
> GrADS script:
>
> /***********************************/
>
> 'open easthl.ctl'
> 'set t 1 144'
> 'set z 1 1'
> etc... etc... etc...
>
> 'set gxout print'
>
> 'display ' rh
> if(rc != 0); return -1; endif
> relhum_timeseries = result <<<<<<<  THIS IS WHERE I GET HOURLY VALUES
>
> REPEAT ABOVE BLOCK FOR u, v, tc, swdown.
>
> * init counters etc
>
> file = "h_output.txt"
> tcount = 1
> i = 10
>
> * loop to calculate hourly values
>
> while(tcount < 144)
>
> relhum = subwrd(relhum_timeseries, i) <<<<<< get hourly rh value
> repeat above code for u, v, tc, swdown.
> hlx = calc_htload(relhum, temp, u_comp, v_comp, solarrad)  <<<<< 
> calculate ht load for this hour
> line = temp % " " % relhum % " " % solarrad " " etc etc
> write(file, line)
>
> endwhile
>
> close(file)
>
> /*****************************************/
>
> The above script works. The output file contains all the correct results.
>
> BUT
>
> When it comes to plotting it, I can't find a "clean" way to do it. 
> Ideally I would like something like
>
> ///////
>
> while(tcount < 144)
> ......
> ......
> hlx.tcount = calc_htload(relhum, temp, u_comp, v_comp, solarrad)  <<<<< 
> CALCULATE HEAT LOAD INDEX FOR THIS HOUR
> ......
> endwhile
>
> 'display ' hlx
>
> ///////
>
> where "hli" is an array of sorts.
>
> I've tried lots of approaches, but it is now degenerating into a 
> Monte-Carlo exercise - ie let's try this and see if it works.
>
> Any help would be greatly appreciated - even if it means "no - it can't 
> be done"
>
> Cheers
> FrankQ
>
>
>
>   

-- 

Please note that Charles.Seman at noaa.gov should be considered my NOAA
email address, not cjs at gfdl.noaa.gov.

********************************************************************
 Charles Seman                                Charles.Seman at noaa.gov
 U.S. Department of Commerce / NOAA / OAR
 Geophysical Fluid Dynamics Laboratory         voice: (609) 452-6547
 201 Forrestal Road                              fax: (609) 987-5063
 Princeton, NJ  08540-6649            http://www.gfdl.noaa.gov/~cjs/
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