Re: error using ftsetp to set parameters for ftcurv

On Aug 7, 2009, at 12:58 PM, Jonathan Vigh wrote:

>
> Greetings all,
> I'm trying to use ftcurv to calculate an interpolatory polynomial.
> I'm setting a few parameters beforehand using ftsetp:
>
> ftsetp("sig",5.) ; tension factor: values near zero give a
> cubic spline, large values (e.g.50) result in a near-polynomial line
> ftsetp("sl1",1.) ; specify the slope of the curve at the
> first point
> ftsetp("sln",-1.) ; specify the slope of the curve at the last
> point
> ftsetp("sf1",0) ; the value of sf1 controls whether to use
> the values for sl1 and sln, or compute those values internally.
> Specifically, sf1
> ; = 0 if sl1 and sln are user-specified.
> ; = 1 if sl1 is user-specified, but sln is internally
> calculated.
> ; = 2 if sln is user-specified, but sl1 is internally
> calculated.
> ; = 3 if sl1 and sln are internally calculated - By default the
> slopes at the end points are computed internally.
>
> interpolated_curve = ftcurv(xi,fi,xo) ; xi, fi, and xo have
> been defined in my script
>
> But when I run the script, I get an error:
>> fatal:ftsetp: unrecognized parameter name
>
> The error points to the line:
> ftsetp("sln",-1.) ; specify the slope of the curve at the last
> point
>
> I think the parameter name "sln" is valid - according to this page:
> http://www.ncarg.ucar.edu//ngmath/fitgrid/parameters.html
>
> so I'm not sure what is going on. Does anyone have any ideas?
>
> Thanks,
> Jonathan

Johnathan,

It appears that, by error, "sln" was named "sl2" in the NCL
interface. I will correct this so that NCL will recognize
"sln". However, I am not sure what an
immediate workaround would be. If you use "sl2" in
NCL, then it will get by the NCL checking, but be rejected
at the lower Fortran level. I can't remember why we put
in the two levels of checking.

Thanks for reporting this and I will continue to think
about a workaround.

If you are building NCL from scratch, then you can change
all occurrences of "sl2" and "SL2" in

  $NCARG/ni/src/lib/nfp/fitgridW.c

to "sln" and "SLN".

Fred Clare

>
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>
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Received on Fri Aug 07 2009 - 15:03:18 MDT