Nearly all of the functions below are universal functions and follow
broadcasting and automatic array-looping rules. Exceptions are noted.
Error handling
Errors are handled by returning nans, or other appropriate values.
Some of the special function routines will emit warnings when an error
occurs. By default this is disabled. To enable such messages use
errprint(1)
, and to disable such messages use errprint(0)
.
Example:
>>> print scipy.special.bdtr(-1,10,0.3)
>>> scipy.special.errprint(1)
>>> print scipy.special.bdtr(-1,10,0.3)
Available functions
Airy functions
airy (z) |
Airy functions and their derivatives. |
airye (z) |
Exponentially scaled Airy functions and their derivatives. |
itairy (x) |
Integrals of Airy functions |
Elliptic Functions and Integrals
ellipj (u, m) |
Jacobian elliptic functions |
ellipkm1 (p) |
Complete elliptic integral of the first kind around m = 1 |
ellipkinc (phi, m) |
Incomplete elliptic integral of the first kind |
ellipe (m) |
Complete elliptic integral of the second kind |
ellipeinc (phi, m) |
Incomplete elliptic integral of the second kind |
Bessel Functions
jv (v, z) |
Bessel function of the first kind of real order v |
jn (v, z) |
Bessel function of the first kind of real order v |
jve (v, z) |
Exponentially scaled Bessel function of order v |
yn (n, x) |
Bessel function of the second kind of integer order |
yv (v, z) |
Bessel function of the second kind of real order |
yve (v, z) |
Exponentially scaled Bessel function of the second kind of real order |
kn (n, x) |
Modified Bessel function of the second kind of integer order n |
kv (v, z) |
Modified Bessel function of the second kind of real order v |
kve (v, z) |
Exponentially scaled modified Bessel function of the second kind. |
iv (v, z) |
Modified Bessel function of the first kind of real order |
ive (v, z) |
Exponentially scaled modified Bessel function of the first kind |
hankel1 (v, z) |
Hankel function of the first kind |
hankel1e (v, z) |
Exponentially scaled Hankel function of the first kind |
hankel2 (v, z) |
Hankel function of the second kind |
hankel2e (v, z) |
Exponentially scaled Hankel function of the second kind |
The following is not an universal function:
Zeros of Bessel Functions
These are not universal functions:
Faster versions of common Bessel Functions
j0 (x) |
Bessel function the first kind of order 0 |
j1 (x) |
Bessel function of the first kind of order 1 |
y0 (x) |
Bessel function of the second kind of order 0 |
y1 (x) |
Bessel function of the second kind of order 1 |
i0 (x) |
Modified Bessel function of order 0 |
i0e (x) |
Exponentially scaled modified Bessel function of order 0. |
i1 (x) |
Modified Bessel function of order 1 |
i1e (x) |
Exponentially scaled modified Bessel function of order 1. |
k0 (x) |
Modified Bessel function K of order 0 |
k0e (x) |
Exponentially scaled modified Bessel function K of order 0 |
k1 (x) |
Modified Bessel function of the first kind of order 1 |
k1e (x) |
Exponentially scaled modified Bessel function K of order 1 |
Integrals of Bessel Functions
itj0y0 (x) |
Integrals of Bessel functions of order 0 |
it2j0y0 (x) |
Integrals related to Bessel functions of order 0 |
iti0k0 (x) |
Integrals of modified Bessel functions of order 0 |
it2i0k0 (x) |
Integrals related to modified Bessel functions of order 0 |
besselpoly (a, lmb, nu) |
Weighted integral of a Bessel function. |
Derivatives of Bessel Functions
Spherical Bessel Functions
These are not universal functions:
Riccati-Bessel Functions
These are not universal functions:
Struve Functions
struve (v, x) |
Struve function |
modstruve (v, x) |
Modified Struve function |
itstruve0 (x) |
Integral of the Struve function of order 0 |
it2struve0 (x) |
Integral related to Struve function of order 0 |
itmodstruve0 (x) |
Integral of the modified Struve function of order 0 |
Raw Statistical Functions
See also
scipy.stats
: Friendly versions of these functions.
bdtr (k, n, p) |
Binomial distribution cumulative distribution function. |
bdtrc (k, n, p) |
Binomial distribution survival function. |
bdtri (k, n, y) |
Inverse function to bdtr vs. |
bdtrik (y, n, p) |
Inverse function to bdtr vs k |
bdtrin (k, y, p) |
Inverse function to bdtr vs n |
btdtr (a, b, x) |
Cumulative beta distribution. |
btdtri (a, b, p) |
p-th quantile of the beta distribution. |
btdtria (p, b, x) |
Inverse of btdtr vs a |
btdtrib (a, p, x) |
Inverse of btdtr vs b |
fdtr (dfn, dfd, x) |
F cumulative distribution function |
fdtrc (dfn, dfd, x) |
F survival function |
fdtri (dfn, dfd, p) |
Inverse to fdtr vs x |
fdtridfd (dfn, p, x) |
Inverse to fdtr vs dfd |
gdtr (a, b, x) |
Gamma distribution cumulative density function. |
gdtrc (a, b, x) |
Gamma distribution survival function. |
gdtria (p, b, x[, out]) |
Inverse of gdtr vs a. |
gdtrib (a, p, x[, out]) |
Inverse of gdtr vs b. |
gdtrix (a, b, p[, out]) |
Inverse of gdtr vs x. |
nbdtr (k, n, p) |
Negative binomial cumulative distribution function |
nbdtrc (k, n, p) |
Negative binomial survival function |
nbdtri (k, n, y) |
Inverse of nbdtr vs p |
nbdtrik (y, n, p) |
Inverse of nbdtr vs k |
nbdtrin (k, y, p) |
Inverse of nbdtr vs n |
ncfdtr (dfn, dfd, nc, f) |
Cumulative distribution function of the non-central F distribution. |
ncfdtridfd (p, f, dfn, nc) |
Calculate degrees of freedom (denominator) for the noncentral F-distribution. |
ncfdtridfn (p, f, dfd, nc) |
Calculate degrees of freedom (numerator) for the noncentral F-distribution. |
ncfdtri (p, dfn, dfd, nc) |
Inverse cumulative distribution function of the non-central F distribution. |
ncfdtrinc (p, f, dfn, dfd) |
Calculate non-centrality parameter for non-central F distribution. |
nctdtr (df, nc, t) |
Cumulative distribution function of the non-central t distribution. |
nctdtridf (p, nc, t) |
Calculate degrees of freedom for non-central t distribution. |
nctdtrit (df, nc, p) |
Inverse cumulative distribution function of the non-central t distribution. |
nctdtrinc (df, p, t) |
Calculate non-centrality parameter for non-central t distribution. |
nrdtrimn (p, x, std) |
Calculate mean of normal distribution given other params. |
nrdtrisd (p, x, mn) |
Calculate standard deviation of normal distribution given other params. |
pdtr (k, m) |
Poisson cumulative distribution function |
pdtrc (k, m) |
Poisson survival function |
pdtri (k, y) |
Inverse to pdtr vs m |
pdtrik (p, m) |
Inverse to pdtr vs k |
stdtr (df, t) |
Student t distribution cumulative density function |
stdtridf (p, t) |
Inverse of stdtr vs df |
stdtrit (df, p) |
Inverse of stdtr vs t |
chdtr (v, x) |
Chi square cumulative distribution function |
chdtrc (v, x) |
Chi square survival function |
chdtri (v, p) |
Inverse to chdtrc |
chdtriv (p, x) |
Inverse to chdtr vs v |
ndtr (x) |
Gaussian cumulative distribution function |
log_ndtr (x) |
Logarithm of Gaussian cumulative distribution function |
ndtri (y) |
Inverse of ndtr vs x |
chndtr (x, df, nc) |
Non-central chi square cumulative distribution function |
chndtridf (x, p, nc) |
Inverse to chndtr vs df |
chndtrinc (x, df, p) |
Inverse to chndtr vs nc |
chndtrix (p, df, nc) |
Inverse to chndtr vs x |
smirnov (n, e) |
Kolmogorov-Smirnov complementary cumulative distribution function |
smirnovi (n, y) |
Inverse to smirnov |
kolmogorov (y) |
Complementary cumulative distribution function of Kolmogorov distribution |
kolmogi (p) |
Inverse function to kolmogorov |
tklmbda (x, lmbda) |
Tukey-Lambda cumulative distribution function |
logit (x) |
Logit ufunc for ndarrays. |
expit (x) |
Expit ufunc for ndarrays. |
boxcox (x, lmbda) |
Compute the Box-Cox transformation. |
boxcox1p (x, lmbda) |
Compute the Box-Cox transformation of 1 + x. |
inv_boxcox (y, lmbda) |
Compute the inverse of the Box-Cox transformation. |
inv_boxcox1p (y, lmbda) |
Compute the inverse of the Box-Cox transformation. |
Error Function and Fresnel Integrals
erf (z) |
Returns the error function of complex argument. |
erfc (x) |
Complementary error function, 1 - erf(x). |
erfcx (x) |
Scaled complementary error function, exp(x^2) erfc(x). |
erfi (z) |
Imaginary error function, -i erf(i z). |
wofz (z) |
Faddeeva function |
dawsn (x) |
Dawson’s integral. |
fresnel (z) |
Fresnel sin and cos integrals |
modfresnelp (x) |
Modified Fresnel positive integrals |
modfresnelm (x) |
Modified Fresnel negative integrals |
These are not universal functions:
Legendre Functions
lpmv (m, v, x) |
Associated legendre function of integer order. |
sph_harm (m, n, theta, phi) |
Compute spherical harmonics. |
These are not universal functions:
Orthogonal polynomials
The following functions evaluate values of orthogonal polynomials:
eval_legendre (n, x[, out]) |
Evaluate Legendre polynomial at a point. |
eval_chebyt (n, x[, out]) |
Evaluate Chebyshev T polynomial at a point. |
eval_chebyu (n, x[, out]) |
Evaluate Chebyshev U polynomial at a point. |
eval_chebyc (n, x[, out]) |
Evaluate Chebyshev C polynomial at a point. |
eval_chebys (n, x[, out]) |
Evaluate Chebyshev S polynomial at a point. |
eval_jacobi (n, alpha, beta, x[, out]) |
Evaluate Jacobi polynomial at a point. |
eval_laguerre (n, x[, out]) |
Evaluate Laguerre polynomial at a point. |
eval_genlaguerre (n, alpha, x[, out]) |
Evaluate generalized Laguerre polynomial at a point. |
eval_hermite (n, x[, out]) |
Evaluate Hermite polynomial at a point. |
eval_hermitenorm (n, x[, out]) |
Evaluate normalized Hermite polynomial at a point. |
eval_gegenbauer (n, alpha, x[, out]) |
Evaluate Gegenbauer polynomial at a point. |
eval_sh_legendre (n, x[, out]) |
Evaluate shifted Legendre polynomial at a point. |
eval_sh_chebyt (n, x[, out]) |
Evaluate shifted Chebyshev T polynomial at a point. |
eval_sh_chebyu (n, x[, out]) |
Evaluate shifted Chebyshev U polynomial at a point. |
eval_sh_jacobi (n, p, q, x[, out]) |
Evaluate shifted Jacobi polynomial at a point. |
The functions below, in turn, return the polynomial coefficients in
orthopoly1d
objects, which function similarly as numpy.poly1d.
The orthopoly1d
class also has an attribute weights
which returns
the roots, weights, and total weights for the appropriate form of Gaussian
quadrature. These are returned in an n x 3
array with roots in the first
column, weights in the second column, and total weights in the final column.
Note that orthopoly1d
objects are converted to poly1d
when doing
arithmetic, and lose information of the original orthogonal polynomial.
Warning
Computing values of high-order polynomials (around order > 20
) using
polynomial coefficients is numerically unstable. To evaluate polynomial
values, the eval_*
functions should be used instead.
Roots and weights for orthogonal polynomials
Hypergeometric Functions
hyp2f1 (a, b, c, z) |
Gauss hypergeometric function 2F1(a, b; c; z). |
hyp1f1 (a, b, x) |
Confluent hypergeometric function 1F1(a, b; x) |
hyperu (a, b, x) |
Confluent hypergeometric function U(a, b, x) of the second kind |
hyp2f0 (a, b, x, type) |
Hypergeometric function 2F0 in y and an error estimate |
hyp1f2 (a, b, c, x) |
Hypergeometric function 1F2 and error estimate |
hyp3f0 (a, b, c, x) |
Hypergeometric function 3F0 in y and an error estimate |
Parabolic Cylinder Functions
pbdv (v, x) |
Parabolic cylinder function D |
pbvv (v, x) |
Parabolic cylinder function V |
pbwa (a, x) |
Parabolic cylinder function W |
These are not universal functions:
Spheroidal Wave Functions
pro_ang1 (m, n, c, x) |
Prolate spheroidal angular function of the first kind and its derivative |
pro_rad1 (m, n, c, x) |
Prolate spheroidal radial function of the first kind and its derivative |
pro_rad2 (m, n, c, x) |
Prolate spheroidal radial function of the secon kind and its derivative |
obl_ang1 (m, n, c, x) |
Oblate spheroidal angular function of the first kind and its derivative |
obl_rad1 (m, n, c, x) |
Oblate spheroidal radial function of the first kind and its derivative |
obl_rad2 (m, n, c, x) |
Oblate spheroidal radial function of the second kind and its derivative. |
pro_cv (m, n, c) |
Characteristic value of prolate spheroidal function |
obl_cv (m, n, c) |
Characteristic value of oblate spheroidal function |
The following functions require pre-computed characteristic value:
pro_ang1_cv (m, n, c, cv, x) |
Prolate spheroidal angular function pro_ang1 for precomputed characteristic value |
pro_rad1_cv (m, n, c, cv, x) |
Prolate spheroidal radial function pro_rad1 for precomputed characteristic value |
pro_rad2_cv (m, n, c, cv, x) |
Prolate spheroidal radial function pro_rad2 for precomputed characteristic value |
obl_ang1_cv (m, n, c, cv, x) |
Oblate spheroidal angular function obl_ang1 for precomputed characteristic value |
obl_rad1_cv (m, n, c, cv, x) |
Oblate spheroidal radial function obl_rad1 for precomputed characteristic value |
obl_rad2_cv (m, n, c, cv, x) |
Oblate spheroidal radial function obl_rad2 for precomputed characteristic value |
Kelvin Functions
kelvin (x) |
Kelvin functions as complex numbers |
ber (x) |
Kelvin function ber. |
bei (x) |
Kelvin function bei |
berp (x) |
Derivative of the Kelvin function ber |
beip (x) |
Derivative of the Kelvin function bei |
ker (x) |
Kelvin function ker |
kei (x) |
Kelvin function ker |
kerp (x) |
Derivative of the Kelvin function ker |
keip (x) |
Derivative of the Kelvin function kei |
These are not universal functions:
Other Special Functions
binom (n, k) |
Binomial coefficient |
expn (n, x) |
Exponential integral E_n |
exp1 (z) |
Exponential integral E_1 of complex argument z |
expi (x) |
Exponential integral Ei |
shichi (x) |
Hyperbolic sine and cosine integrals |
sici (x) |
Sine and cosine integrals |
spence (x) |
Dilogarithm integral |
zeta (x, q) |
Hurwitz zeta function |
zetac (x) |
Riemann zeta function minus 1. |
Convenience Functions
cbrt (x) |
Cube root of x |
exp10 (x) |
10**x |
exp2 (x) |
2**x |
radian (d, m, s) |
Convert from degrees to radians |
cosdg (x) |
Cosine of the angle x given in degrees. |
sindg (x) |
Sine of angle given in degrees |
tandg (x) |
Tangent of angle x given in degrees. |
cotdg (x) |
Cotangent of the angle x given in degrees. |
log1p (x) |
Calculates log(1+x) for use when x is near zero |
expm1 (x) |
exp(x) - 1 for use when x is near zero. |
cosm1 (x) |
cos(x) - 1 for use when x is near zero. |
round (x) |
Round to nearest integer |
xlogy (x, y) |
Compute x*log(y) so that the result is 0 if x = 0 . |
xlog1py (x, y) |
Compute x*log1p(y) so that the result is 0 if x = 0 . |
exprel (x) |
Relative error exponential, (exp(x)-1)/x, for use when x is near zero. |