2 * Generally useful stuff.
7 double magnD(const double pq[D3]) {
8 return sqrt(magnD2(pq));
11 double magnD2(const double pq[D3]) {
15 K d2= ffsqa(pq[k], d2);
19 double hypotD(const double p[D3], const double q[D3]) {
27 double hypotD2(const double p[D3], const double q[D3]) {
31 K d2= ffsqa(p[k] - q[k], d2);
35 double hypotD2plus(const double p[D3], const double q[D3], double d2) {
37 K d2= ffsqa(p[k] - q[k], d2);
41 void xprod(double r[D3], const double a[D3], const double b[D3]) {
42 r[0]= a[1]*b[2] - a[2]*b[1];
43 r[1]= a[2]*b[0] - a[0]*b[2];
44 r[2]= a[0]*b[1] - a[1]*b[0];
47 void normalise(double v[D3], double one, double absepsilon) {
49 double multby= one/(magnD(v) + absepsilon);
53 void xprod_norm(double r[D3], const double a[D3], const double b[D3],
54 double one, double absepsilon) {
56 normalise(r, absepsilon, one);
59 double dotprod(const double a[D3], const double b[D3]) {
62 K result += a[k] * b[k];
66 void libdie(const char *lib, int l, const char *str) {
67 fprintf(stderr,"%s library call failed, line %d: %s\n", lib, l, str);
70 void gsldie(int l, const char *what, int status) {
71 fprintf(stderr,"gsl function failed, line %d: %s: %s\n",
72 l, what, gsl_strerror(status));
76 void diee(const char *what) { perror(what); exit(16); }
77 void fail(const char *emsg) { fputs(emsg,stderr); exit(12); }
78 void flushoutput(void) { if (ferror(stdout)||fflush(stdout)) diee("stdout"); }