diff options
Diffstat (limited to 'libdimension/polynomial.c')
| -rw-r--r-- | libdimension/polynomial.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/libdimension/polynomial.c b/libdimension/polynomial.c index 9d2ac6a..136b0b5 100644 --- a/libdimension/polynomial.c +++ b/libdimension/polynomial.c @@ -357,10 +357,10 @@ dmnsn_solve_cubic(double poly[4], double x[3]) double p = poly[1] - b2/3.0; double q = poly[0] - poly[2]*(9.0*poly[1] - 2.0*b2)/27.0; - double det = 4.0*p*p*p + 27.0*q*q; + double disc = 4.0*p*p*p + 27.0*q*q; double bdiv3 = poly[2]/3; - if (det <= -dmnsn_epsilon) { + if (disc <= -dmnsn_epsilon) { /* Three real roots -- this implies p < 0 */ double msqrtp3 = -sqrt(-p/3.0); double theta = acos(3*q/(2*p*msqrtp3))/3.0; @@ -381,11 +381,11 @@ dmnsn_solve_cubic(double poly[4], double x[3]) } } else { /* One real root */ - if (det < 0.0) - det = 0.0; + if (disc < 0.0) + disc = 0.0; - double cbrtdet = cbrt(sqrt(det/108.0) + fabs(q)/2.0); - double abst = cbrtdet - p/(3.0*cbrtdet); + double cbrtdiscq = cbrt(sqrt(disc/108.0) + fabs(q)/2.0); + double abst = cbrtdiscq - p/(3.0*cbrtdiscq); if (q >= 0) { x[0] = -abst - bdiv3; |