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/* initds.f -- translated by f2c (version 20041007).
You must link the resulting object file with libf2c:
on Microsoft Windows system, link with libf2c.lib;
on Linux or Unix systems, link with .../path/to/libf2c.a -lm
or, if you install libf2c.a in a standard place, with -lf2c -lm
-- in that order, at the end of the command line, as in
cc *.o -lf2c -lm
Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
http://www.netlib.org/f2c/libf2c.zip
*/
#define V3P_NETLIB_SRC
#include "v3p_netlib.h"
/* Table of constant values */
static integer c__2 = 2;
static integer c__1 = 1;
/* DECK INITDS */
integer initds_(doublereal *os, integer *nos, real *eta)
{
/* System generated locals */
integer ret_val, i__1;
real r__1;
/* Local variables */
integer i__ = 0, ii;
real err;
extern /* Subroutine */ int xermsg_(char *, char *, char *, integer *,
integer *, ftnlen, ftnlen, ftnlen);
/* ***BEGIN PROLOGUE INITDS */
/* ***PURPOSE Determine the number of terms needed in an orthogonal */
/* polynomial series so that it meets a specified accuracy. */
/* ***LIBRARY SLATEC (FNLIB) */
/* ***CATEGORY C3A2 */
/* ***TYPE DOUBLE PRECISION (INITS-S, INITDS-D) */
/* ***KEYWORDS CHEBYSHEV, FNLIB, INITIALIZE, ORTHOGONAL POLYNOMIAL, */
/* ORTHOGONAL SERIES, SPECIAL FUNCTIONS */
/* ***AUTHOR Fullerton, W., (LANL) */
/* ***DESCRIPTION */
/* Initialize the orthogonal series, represented by the array OS, so */
/* that INITDS is the number of terms needed to insure the error is no */
/* larger than ETA. Ordinarily, ETA will be chosen to be one-tenth */
/* machine precision. */
/* Input Arguments -- */
/* OS double precision array of NOS coefficients in an orthogonal */
/* series. */
/* NOS number of coefficients in OS. */
/* ETA single precision scalar containing requested accuracy of */
/* series. */
/* ***REFERENCES (NONE) */
/* ***ROUTINES CALLED XERMSG */
/* ***REVISION HISTORY (YYMMDD) */
/* 770601 DATE WRITTEN */
/* 890531 Changed all specific intrinsics to generic. (WRB) */
/* 890831 Modified array declarations. (WRB) */
/* 891115 Modified error message. (WRB) */
/* 891115 REVISION DATE from Version 3.2 */
/* 891214 Prologue converted to Version 4.0 format. (BAB) */
/* 900315 CALLs to XERROR changed to CALLs to XERMSG. (THJ) */
/* ***END PROLOGUE INITDS */
/* ***FIRST EXECUTABLE STATEMENT INITDS */
/* Parameter adjustments */
--os;
/* Function Body */
if (*nos < 1) {
xermsg_("SLATEC", "INITDS", "Number of coefficients is less than 1", &
c__2, &c__1, (ftnlen)6, (ftnlen)6, (ftnlen)37);
}
err = 0.f;
i__1 = *nos;
for (ii = 1; ii <= i__1; ++ii) {
i__ = *nos + 1 - ii;
err += (r__1 = (real) os[i__], (real) dabs(r__1));
if (err > *eta) {
goto L20;
}
/* L10: */
}
L20:
if (i__ == *nos) {
xermsg_("SLATEC", "INITDS", "Chebyshev series too short for specifie"
"d accuracy", &c__1, &c__1, (ftnlen)6, (ftnlen)6, (ftnlen)49);
}
ret_val = i__;
return ret_val;
} /* initds_ */
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