[gradsusr] A Faulty IF Loop

[Jeff Duda]

You need to be very explicit with your translation of human statements into
code. You might say, "if the lag is 1, 5, 9, or 13 I want to do one thing,
and do something different if otherwise." But to convert that to code you
need to explicitly spell out EACH logical expression:
if lag is 1
if lag is 5
if lag is 9
if lag is 13

Thus, your if statement should read:
*if (lag = 1 | lag = 5 | lag = 9 | lag = 13)*

Jeff

On Tue, Jun 16, 2015 at 4:06 PM, Noska, Ryne <rgn14c at my.fsu.edu> wrote:

>        I have written a very simple code for the purpose of creating one
> image with sixteen figures (four rows and four columns). Unfortunately, the
> loop I have designed to change the location of the next figure is broken.
> Instead of only executing the "if" statement if lag = 1 or 5 or 9 or 13,
> this portion of the loop is ALWAYS executed. The "else" statement is NEVER
> executed, causing the figures to run off the page after figure 4 since
> only ymin and ymax change. Below is a portion of my code; again, the
> problematic portion is the IF loop:
>
>  ---------------------------------------
>
>  xmin = 0.25
> xmax = 2.50
> ymin = 6.25 + 2.00
> ymax = 8.00 + 2.00
>
>  lag = 1
> while (lag <= 16)
>   numlag = lag - 1
>
>   * if (lag = 1 | 5 | 9 | 13)*
> *    xmin = 0.25*
> *    xmax = 2.50*
> *    ymin = ymin - 2.00*
> *    ymax = ymax - 2.00*
> *  else *
> *    xmin = xmin + 2.50*
> *    xmax = xmax + 2.50*
> *  endif*
>
>    xlab = ((xmax - xmin)/2) + 0.25
>   ylab = ymax + 0.125
>
>    'set parea 'xmin' 'xmax' 'ymin' 'ymax
>   'set xlopts 1 1 0.10'
>   'set ylopts 1 1 0.10'
>   'set xlint 10'
>   'set ylint 10'
>   'set xlab off'
>   'set ylab off'
>   'set grid on'
>   'set grads off'
>   'set map 1 1 5'
>   'set clevs -0.8 -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.1 0.2 0.3'
>   'set ccols 9   14   4    11   5   13    3    10   0   7  12  8'
>   'set t 'lag
>   'd corr_grdons'
>   'set strsiz 0.15'
>   'set string 1 c 8'
>   'draw string 'xlab' 'ylab' lag='numlag'days'
>
>    lag = lag + 1
> endwhile
>
>  -------------------------------
>
>  Any suggestions?
>
>  Thank you,
>  Ryne
>
>    ​
>
>
>
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>


-- 
Jeff Duda
Graduate research assistant
University of Oklahoma School of Meteorology
Center for Analysis and Prediction of Storms
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