diff options
Diffstat (limited to 'Modules/_statisticsmodule.c')
| -rw-r--r-- | Modules/_statisticsmodule.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/Modules/_statisticsmodule.c b/Modules/_statisticsmodule.c index 16a9924..a646e96 100644 --- a/Modules/_statisticsmodule.c +++ b/Modules/_statisticsmodule.c @@ -32,8 +32,11 @@ _statistics__normal_dist_inv_cdf_impl(PyObject *module, double p, double mu, /*[clinic end generated code: output=02fd19ddaab36602 input=24715a74be15296a]*/ { double q, num, den, r, x; + if (p <= 0.0 || p >= 1.0 || sigma <= 0.0) { + goto error; + } + q = p - 0.5; - // Algorithm AS 241: The Percentage Points of the Normal Distribution if(fabs(q) <= 0.425) { r = 0.180625 - q * q; // Hash sum-55.8831928806149014439 @@ -53,10 +56,16 @@ _statistics__normal_dist_inv_cdf_impl(PyObject *module, double p, double mu, 6.8718700749205790830e+2) * r + 4.2313330701600911252e+1) * r + 1.0); + if (den == 0.0) { + goto error; + } x = num / den; return mu + (x * sigma); } r = (q <= 0.0) ? p : (1.0 - p); + if (r <= 0.0 || r >= 1.0) { + goto error; + } r = sqrt(-log(r)); if (r <= 5.0) { r = r - 1.6; @@ -97,11 +106,18 @@ _statistics__normal_dist_inv_cdf_impl(PyObject *module, double p, double mu, 5.99832206555887937690e-1) * r + 1.0); } + if (den == 0.0) { + goto error; + } x = num / den; if (q < 0.0) { x = -x; } return mu + (x * sigma); + + error: + PyErr_SetString(PyExc_ValueError, "inv_cdf undefined for these parameters"); + return -1.0; } |