/* nag_cubic_roots (c02akc) Example Program. * * Copyright 2000 Numerical Algorithms Group. * * NAG C Library * * Mark 6, 2000. */ #include #include #include #include int main(void) { double *errest = 0, *zeroi = 0, *zeror = 0; double r, s, t, u; Integer i; Integer exit_status = 0; NagError fail; INIT_FAIL(fail); printf("nag_cubic_roots (c02akc) Example Program Results\n\n"); if ( !(errest = NAG_ALLOC(3, double)) || !(zeroi = NAG_ALLOC(3, double)) || !(zeror = NAG_ALLOC(3, double)) ) { printf("Allocation failure\n"); exit_status = -1; goto END; } /* Skip heading in data file */ scanf("%*[^\n] "); scanf("%lf %lf %lf %lf ", &u, &r, &s, &t); /* nag_cubic_roots (c02akc). * Zeros of a cubic polynomial with real coefficients */ nag_cubic_roots(u, r, s, t, zeror, zeroi, errest, &fail); if (fail.code == NE_NOERROR) { printf( "\n Roots of cubic equation Error estimates\n"); printf( " (machine-dependent)\n\n"); for (i = 0; i <= 2; ++i) { printf(" z = %10.5f %10.5f%s %g\n", zeror[i], zeroi[i], "*i", errest[i]); } } else { printf("Error from nag_cubic_roots (c02akc).\n%s\n", fail.message); exit_status = 1; goto END; } END: if (errest) NAG_FREE(errest); if (zeroi) NAG_FREE(zeroi); if (zeror) NAG_FREE(zeror); return exit_status; }