Add graph references

2026-06-28 13:49:01 +01:00
parent 0a9807e448
commit a11edf0c53
2578 changed files with 868045 additions and 0 deletions
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+/*  -- translated by f2c (version 20240504).
+   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
+*/
+
+#include "f2c.h"
+
+/* Table of constant values */
+
+static doublereal c_b3 = .66666666666666663;
+
+/* -----------------------------------------------------------------------
+   \BeginDoc
+
+   \Name: dnconv
+
+   \Description:
+    Convergence testing for the nonsymmetric Arnoldi eigenvalue routine.
+
+   \Usage:
+    call dnconv
+       ( N, RITZR, RITZI, BOUNDS, TOL, NCONV )
+
+   \Arguments
+    N       Integer.  (INPUT)
+            Number of Ritz values to check for convergence.
+
+    RITZR,  Double precision arrays of length N.  (INPUT)
+    RITZI   Real and imaginary parts of the Ritz values to be checked
+            for convergence.
+    BOUNDS  Double precision array of length N.  (INPUT)
+            Ritz estimates for the Ritz values in RITZR and RITZI.
+
+    TOL     Double precision scalar.  (INPUT)
+            Desired backward error for a Ritz value to be considered
+            "converged".
+
+    NCONV   Integer scalar.  (OUTPUT)
+            Number of "converged" Ritz values.
+
+   \EndDoc
+
+   -----------------------------------------------------------------------
+
+   \BeginLib
+
+   \Local variables:
+       xxxxxx  real
+
+   \Routines called:
+       arscnd  ARPACK utility routine for timing.
+       dlamch  LAPACK routine that determines machine constants.
+       dlapy2  LAPACK routine to compute sqrt(x**2+y**2) carefully.
+
+   \Author
+       Danny Sorensen               Phuong Vu
+       Richard Lehoucq              CRPC / Rice University
+       Dept. of Computational &     Houston, Texas
+       Applied Mathematics
+       Rice University
+       Houston, Texas
+
+   \Revision history:
+       xx/xx/92: Version ' 2.1'
+
+   \SCCS Information: @(#)
+   FILE: nconv.F   SID: 2.3   DATE OF SID: 4/20/96   RELEASE: 2
+
+   \Remarks
+       1. xxxx
+
+   \EndLib
+
+   -----------------------------------------------------------------------
+
+   Subroutine */ int igraphdnconv_(integer *n, doublereal *ritzr, doublereal *ritzi,
+	 doublereal *bounds, doublereal *tol, integer *nconv)
+{
+    /* System generated locals */
+    integer i__1;
+    doublereal d__1, d__2;
+
+    /* Builtin functions */
+    double pow_dd(doublereal *, doublereal *);
+
+    /* Local variables */
+    integer i__;
+    real t0, t1;
+    doublereal eps23, temp;
+    extern doublereal igraphdlapy2_(doublereal *, doublereal *), igraphdlamch_(char *);
+    extern /* Subroutine */ int igrapharscnd_(real *);
+    real tnconv=0;
+
+
+/*     %----------------------------------------------------%
+       | Include files for debugging and timing information |
+       %----------------------------------------------------%
+
+
+       %------------------%
+       | Scalar Arguments |
+       %------------------%
+
+
+       %-----------------%
+       | Array Arguments |
+       %-----------------%
+
+       %---------------%
+       | Local Scalars |
+       %---------------%
+
+
+       %--------------------%
+       | External Functions |
+       %--------------------%
+
+       %-----------------------%
+       | Executable Statements |
+       %-----------------------%
+
+       %-------------------------------------------------------------%
+       | Convergence test: unlike in the symmetric code, I am not    |
+       | using things like refined error bounds and gap condition    |
+       | because I don't know the exact equivalent concept.          |
+       |                                                             |
+       | Instead the i-th Ritz value is considered "converged" when: |
+       |                                                             |
+       |     bounds(i) .le. ( TOL * | ritz | )                       |
+       |                                                             |
+       | for some appropriate choice of norm.                        |
+       %-------------------------------------------------------------%
+
+       Parameter adjustments */
+    --bounds;
+    --ritzi;
+    --ritzr;
+
+    /* Function Body */
+    igrapharscnd_(&t0);
+
+/*     %---------------------------------%
+       | Get machine dependent constant. |
+       %---------------------------------% */
+
+    eps23 = igraphdlamch_("Epsilon-Machine");
+    eps23 = pow_dd(&eps23, &c_b3);
+
+    *nconv = 0;
+    i__1 = *n;
+    for (i__ = 1; i__ <= i__1; ++i__) {
+/* Computing MAX */
+	d__1 = eps23, d__2 = igraphdlapy2_(&ritzr[i__], &ritzi[i__]);
+	temp = max(d__1,d__2);
+	if (bounds[i__] <= *tol * temp) {
+	    ++(*nconv);
+	}
+/* L20: */
+    }
+
+    igrapharscnd_(&t1);
+    tnconv += t1 - t0;
+
+    return 0;
+
+/*     %---------------%
+       | End of dnconv |
+       %---------------% */
+
+} /* igraphdnconv_ */
+