merge

[moebius2.git] / common.c

diff --git a/common.c b/common.c
index 34381e890494a489c95e0161856dccdc598a6ce6..bfe11b7dc23851e0e427f45533a86d9df2f0b112 100644 (file)
--- a/common.c
+++ b/common.c
@@ -5,14 +5,15 @@
 #include "common.h"
 
 double magnD(const double pq[D3]) {
-  gsl_vector v;
-
-  v.size= D3;
-  v.stride= 1;
-  v.data= (double*)pq;
-  /* owner and block ought not to be used */
+  return sqrt(magnD2(pq));
+}
 
-  return gsl_blas_dnrm2(&v);
+double magnD2(const double pq[D3]) {
+  int k;
+  double d2= 0;
+  
+  K d2= ffsqa(pq[k], d2);
+  return d2;
 }
 
 double hypotD(const double p[D3], const double q[D3]) {
@@ -43,6 +44,18 @@ void xprod(double r[D3], const double a[D3], const double b[D3]) {
   r[2]= a[0]*b[1] - a[1]*b[0];
 }
 
+void normalise(double v[D3], double one, double absepsilon) {
+  int k;
+  double multby= one/(magnD(v) + absepsilon);
+  K v[k] *= multby;
+}
+
+void xprod_norm(double r[D3], const double a[D3], const double b[D3],
+               double one, double absepsilon) {
+  xprod(r,a,b);
+  normalise(r, absepsilon, one);
+}
+
 double dotprod(const double a[D3], const double b[D3]) {
   int k;
   double result= 0;
@@ -61,4 +74,5 @@ void gsldie(int l, const char *what, int status) {
 }
 
 void diee(const char *what) { perror(what); exit(16); }
-void flushoutput(void) { if (fflush(stdout)||ferror(stdout)) diee("stdout"); }
+void fail(const char *emsg) { fputs(emsg,stderr); exit(12); }
+void flushoutput(void) { if (ferror(stdout)||fflush(stdout)) diee("stdout"); }