[gradsusr] plotting problem

[frankq]

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



-- 
*Dr Frank Quintarelli | Software Development Manager*

Katestone Environmental Pty Ltd | ABN 92 097 270 276

Terrace 5, 249 Coronation Drive, PO Box 2217 Milton Queensland, Australia

Ph +61 7 3369 3699 | Fax +61 7 3369 1966

frankqAtkatestoneDotcomDotau | *wwwDotkatestoneDotcomDotau*