news

math library from gnu

* What is new in gsl-1.12:

** Upgraded to latest libtool, autoconf and automake (libtool-2.2.6,
   autoconf-2.63, automake-1.10.2)

** Improved the convergence of gsl_sf_gamma_inc_P for x/a ~=~ 1 and
   large x,a.  Fixes problems with large arguments in cdf functions
   such as gsl_cdf_chisq_Pinv(x,nu) [bug 24704].

** Fixed gsl_ran_gamma_knuth to handle the case of a >= UINT_MAX [bug
   #24897]

** Added gsl_bspline_eval_deriv to compute bspline derivatives
   (Rhys Ulerich)

** Added a faster simplex mininimser gsl_multimin_fminimizer_nmsimplex2
   which is O(N) instead of O(N^2) [bug #24418]

** Improved the original chi-squared formula in gsl_monte_vegas to
   avoid catastrophic cancellation [bug #24510].  The previous formula
   could return incorrect or negative values for relative errors <
   1e-8, which could occur when integrating very smooth functions.

** Added new auxiliary functions gsl_cheb_order, gsl_cheb_size,
   gsl_cheb_coeffs for Chebyshev series [bug #21830]

** Updated license of the reference manual to GNU FDL version 1.3.

** Fixed a bug where the gsl_isinf function would return +1 for -Inf
   on systems where isinf(-Inf) returns the non-standard value +1.
   [bug #24489]

** Added missing functions gsl_vector_complex_{isnonneg,add,sub,mul,
   div,scale,add_constant} and gsl_matrix_complex_float_isnonneg [bug
   #22478]

** Cross compilation should now work for x86 hosts.

** Fixed a bug in gsl_interp_accel_find() where values lying on the
   upper boundary between interpolation points could return the index
   from the lower side. [bug #24211]

** Fixed gsl_linalg_solve_cyc_tridiag so that its output respects the
   solution vector's stride. Previously the x_stride value was ignored
   causing the output to be incorrect for non-unit stride. [bug #24162]

** Corrected a bug in the series calculation of gsl_sf_ellint_Kcomp
   for k close to 1. [bug #24146]

** Extended gsl_linalg_QRPT_update to handle rectangular matrices.
   Corrected definition of the update formula in the manual for
   both gsl_linalg_QR_update and gsl_linalg_QRPT_update.

** Added routine gsl_linalg_cholesky_invert

** Fixed a bug the simplex algorithm which caused the second highest
   point to be incorrectly equal to the first when the first value was
   the highest, which could cause suboptimal convergence. [bug #23192]

** Fixed a problem with convergence for inverse gamma and chisq
   distribitions, gsl_cdf_gamma_{P,Q}inv and gsl_cdf_chisq_{P,Q}inv.
   [bug #23101]

** Improved the handling of constant regions in Vegas by eliminating
   spurious excess precision when computing box variances.

** Fixed a potential division by zero in gsl_monte_miser when the
   left/right weight factors decrease below 1.

** Fixed incorrect dimensions check in gsl_matrix_sub{row,column}

* What was new in gsl-1.11:

** The GSL repository and bug database are now hosted at Savannah
   http://savannah.gnu.org/projects/gsl/

** Upgraded to latest libtool, autoconf and automake (libtool-2.2,
   autoconf-2.61, automake-1.10.1)

** Fixed underflow in ODE adaptive step size controller that could
   cause step size to decrease to zero (bug #21933).

** Improved the handling of the asymptotic regime in gsl_sf_bessel_jl.

** Improved the handling of large arguments in cumulative distribution
   functions using the incomplete beta function, such as gsl_cdf_fdist_P.

** Fixed overflow bug in gsl_cdf_hypergeometric_{P,Q} for large
   arguments (bug #22293).

** gsl_ran_gaussian_ziggurat now handles generators with different
   ranges explicitly, to minimise the number of function calls
   required (bug #21820).  Also fixes bug #22446 (rng limit in
   gsl_ran_chisq()).

** Added missing error terms in gsl_sf_exp_mult_e10_e to prevent
   the error being underestimated (bug #22041).  

** Updated some constants to the CODATA 2006 values.

** The hypergeometric function gsl_sf_hyperg_2F1 now handles the case
   where x==1.

** Fixed a bug in the brent minimiser which prevented optimal convergence.

** Added functions for evaluating complex polynomials

** The convergence condition for gsl_multiroots_test_delta now accepts
   dxi == 0.

** Improved functions gsl_ldexp and gsl_frexp to handle the full range
   of double precision numbers in all cases.

** Added new quasi random generators gsl_qrng_halton and
   gsl_qrng_reversehalton which support dimensions up to 1229.

** Added function gsl_multifit_linear_residuals for computing the
   residuals of the fit

* What was new in gsl-1.10:

** License updated to GNU GPL version 3.

** Added support for generalized eigensystems

** Added function gsl_stats_correlation to compute Pearson correlation
of two datasets

** Added the new function gsl_sf_expint(n,x) for computing the n-th
order exponential integral.

** Added functions gsl_vector_isnonneg and gsl_matrix_isnonneg.

** Added functions gsl_matrix_subrow and gsl_matrix_subcolumn

** Extended Cholesky routines to complex matrices

** Added support in gsl_ieee_set_mode for controlling SSE exceptions
and rounding through the MXCSR control word on x86 processors.

** The autoconf macro AM_PATH_GSL has been renamed to AX_PATH_GSL, to
avoid conflicts with the autoconf namespace.

** Improved handling of underflow in gsl_eigen_symm.

** The function gsl_multiroot_fdjacobian now returns the error code
GSL_ESING if any of the columns of the computed jacobian matrix are
zero.  This may occur if the step size of the derivative is too small.

** Extended the function gsl_sf_beta_inc(a,b,x) to handle cases where
a<0 or b<0.

** Fixed the round-off error estimate in gsl_deriv_{central,backwards,
forward} to correctly account for numerical error in the step-size h.

** Fixed gsl_cdf_beta_Pinv, gsl_cdf_gamma_Pinv, gsl_cdf_beta_Pinv to
avoid returning spurious values for large parameters when the
iteration did not converge.  If the iteration cannot converge, GSL_NAN
is returned.

** gsl_ran_dirichlet now handles smaller values of alpha[] without
underflow, avoiding a NaN in the returned value.

** The SVD routines now avoid underflow in the Schur decomposition for
matrices with extremely small values <O(1e-150).

** gsl_complex_pow now returns 0^0=1 (instead of zero) to match the usual
pow function, and handles z^(1,0) and z^(-1,0) as special cases.

** Fixed a bug in the set function for multifit lmder solver so that
previous values are cleared correctly.

** Improved the function gsl_log1p to prevent possible loss of
accuracy caused by optimisations.

** Improved the convergence test in the Lambert functions to take
account of finite precision and avoid possible failure to converge.

** The configure script no longer redefines finite() to isfinite() as
a workaround for missing finite(), as this caused problems on Solaris.
If finite() is not present gsl_finite() will be used instead.

** Improved the accuracy of the generalised laguerre polynomials for
large n when alpha=0.

** The functions gsl_{isnan,isinf,finite} will now always use the
system versions of isnan, isinf and finite if they are available.
Previously the portable GSL implementations were used whenever the
platform supported IEEE comparisons.  The portable gsl_isinf function
now returns -1 instead of +1 for -Inf, in line with recent versions of
the GNU C Library.

* What was new in gsl-1.9:

** Fixed the elliptic integrals F,E,P,D so that they have the correct
behavior for phi > pi/2 and phi < 0.  The angular argument is now
valid for all phi.  Also added the complete elliptic integral
gsl_sf_ellint_Pcomp.

** Added a new BFGS minimisation method gsl_multimin_fdfminimizer_vector_bfgs2
based on the algorithm given by R.Fletcher in "Practical Methods of
Optimisation" (Second edition).  This requires substantially fewer
function and gradient evaluations, and supercedes the existing BFGS
minimiser.

** The beta functions gsl_sf_beta_e(a,b) and gsl_sf_lnbeta_e(a,b) now
handle negative arguments a,b.  Added new function gsl_sf_lnbeta_sgn_e
for computing magnitude and sign of negative beta values, analagous to
gsl_sf_lngamma_sgn_e.

** gsl_cheb_eval_mode now uses the same error estimate as
gsl_cheb_eval_err.

** Improved gsl_sf_legendre_sphPlm_e to avoid underflow with large
arguments.

** Added updated Knuth generator, gsl_rng_knuthran2002, from 9th
printing of "The Art of Computer Programming".  Fixes various
weaknesses in the earlier version gsl_rng_knuthran.  See
http://www-cs-faculty.stanford.edu/~knuth/news02.htm

** The functions gsl_multifit_fsolver_set, gsl_multifit_fdfsolver_set
and gsl_multiroot_fsolver_set, gsl_multiroot_fdfsolver_set now have a
const qualifier for the input vector x, reflecting their actual usage.

** gsl_sf_expint_E2(x) now returns the correct value 1 for x==0,
instead of NaN.

** The gsl_ran_gamma function now uses the Marsaglia-Tsang fast gamma
method of gsl_ran_gamma_mt by default.

** The matrix and vector min/max functions now always propagate any
NaNs in their input.

** Prevented NaN occuring for extreme parameters in
gsl_cdf_fdist_{P,Q}inv and gsl_cdf_beta_{P,Q}inv

** Corrected error estimates for the angular reduction functions
gsl_sf_angle_restrict_symm_err and gsl_sf_angle_restrict_pos_err.
Fixed gsl_sf_angle_restrict_pos to avoid possibility of returning
small negative values.  Errors are now reported for out of range
negative arguments as well as positive.  These functions now return
NaN when there would be significant loss of precision.

** Corrected an error in the higher digits of M_PI_4 (this was beyond
the limit of double precision, so double precision results are not
affected).

** gsl_root_test_delta now always returns success if two iterates are
the same, x1==x0.

** A Japanese translation of the reference manual is now available
from the GSL webpage at http://www.gnu.org/software/gsl/ thanks to
Daisuke TOMINAGA.

** Added new functions for basis splines, see the "Basis Splines"
chapter in the GSL Reference Manual for details.

** Added new functions for testing the sign of vectors and matrices,
gsl_vector_ispos, gsl_vector_isneg, gsl_matrix_ispos and
gsl_matrix_isneg.

** Fixed a bug in gsl_sf_lnpoch_e and gsl_sf_lnpoch_sgn_e which caused
the incorrect value 1.0 instead of 0.0 to be returned for x==0.

** Fixed cancellation error in gsl_sf_laguerre_n for n > 1e7 so that
larger arguments can be calculated without loss of precision.

** Improved gsl_sf_zeta_e to return exactly zero for negative even
integers, avoiding less accurate trigonometric reduction.

** Fixed a bug in gsl_sf_zetam1_int_e where 0 was returned instead of
-1 for negative even integer arguments.

** When the differential equation solver gsl_odeiv_apply encounters a
singularity it returns the step-size which caused the error code from
the user-defined function, as opposed to leaving the step-size
unchanged.

** Added support for nonsymmetric eigensystems

** Added Mathieu functions

* What was new in gsl-1.8:

** Added an error check to trap multifit calls with fewer observations
than parameters.  Previously calling the multifit routines with n<p
would cause invalid memory access.

** Added the Debye unit to physical constants.

** Added cumulative distribution functions for the discrete
distributions, including binomial, poisson, geometric, negative
binomial, pascal and hypergeometric.

** Added the functions gsl_cdf_beta_{Pinv,Qinv} and
gsl_cdf_fdist_{Pinv,Qinv} for computing the inverse of the cumulative
beta and F distributions.

** Added the multilinear fit estimator function gsl_multifit_linear_est
for computing model values and their errors.

** Avoid division by zero in gsl_multimin_fdfminimizer_vector_bfgs
if the step-size becomes too small.

** Users on DEC Alpha systems will need to specify their desired IEEE
arithmetic options via CFLAGS when building the library, as these are
no longer added automatically.

** Added new random variate generators gsl_ran_gaussian_ziggurat
and gsl_ran_gamma_mt for the Gaussian and Gamma distributions based on
the Marsaglia-Tsang ziggurat and fast gamma methods.

** Improved the speed of the exponential power distribution
gsl_ran_exppow.

** Improved the speed of the Gaussian ratio method by adding quadratic
bounds in gsl_ran_gaussian_ratio_method.

** Added an extra term to the taylor series of the synchrotron
functions gsl_sf_synchrotron_1 and gsl_sf_synchrotron_2 for small x to
ensure smooth matching with the chebyshev expansion.