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fft.texi, cheb.texi
- To: gsl-discuss at sources dot redhat dot com
- Subject: fft.texi, cheb.texi
- From: Sean Harbour <sean at sychron dot com>
- Date: Fri, 7 Sep 2001 08:48:53 +0000
- Organization: Sychron
- Reply-To: sean at sychron dot com
Hi,
1. --
I noticed that the example in the file "doc/fft.texi" contains references to an
undefined variable "z", should this be "data" (first few lines).
i.e.
for (i = 0; i < 128; i++)
@{
REAL(z,i) = 0.0;
IMAG(z,i) = 0.0;
@}
becomes...
for (i = 0; i < 128; i++)
@{
REAL(data,i) = 0.0;
IMAG(data,i) = 0.0;
@}
2. --
Also, in the example in file "doc/cheb.texi"
for (x = 0; x < 1; x += 0.001)
@{
double r10 = gsl_cheb_eval_n (cs, 10, x);
double r40 = gsl_cheb_eval (cs, x);
printf ("%g %g %g %g\n", x, GSL_FN_EVAL (&F, x), r10, r40);
@}
The step size is a power of 10 and doesn't have an exact binary representation.
"0.00125" may be better (at least give it a fighting chance) or similar --
people will use this as reference code.
3. --
Again in "doc/cheb.texi" "order" is used where I would expect "degree" to be
used, and "term" where I would expect "order" to be used.
That is, the usual relationship between degree and order is that "order =
degree+1" (as in a polynomial of degree 2 has order 3, a quadratic).
Best wishes,
Sean.