v4.3.0 (14 February 2022)

• Changed constants to static constexpr for efficiency, added Euler's Gamma constant. (#2478)
• Added lmultiply function that parallels multiply_log so that the language doesn't have to rename. (#2596)
• Cleaned up tests to include <CL/opencl.hpp> instead of <CL/cl2.hpp>. (#2610)
• Added missing implementations of that shadow the signatures of math functions in the std:: namespace. (#2612)
• Bugfix for the bug where 2x2 matrix exponential function outputs NaN for matrices with large eigenvalues. (#2616)
• Add compiler flag -D_BOOST_LGAMMA to allow users to force use of Boost lgamma implementation. (#2618)
• More informative error messages for ODE solvers. (#2620)
• Force linker to respect rpath set at compile time. (#2627)
• Upgraded Sundials to 6.0.0. (#2629)
• Added norm1() and norm2(). (#2636)
• Add missing von_mises_cdf_log and von_mises_ccdf_log signatures. (#2640)
• Refactored the DAE solver.(#2644)
• Added the inverse of the complementary error function - inv_erfc(). (#2645)
• Updated member functions for accessing tangents in scalar fvar types. (#2652)
• Added support for the new matrix type for GLM functions. (#2655)

v4.3.0-rc1 (31 January 2022)

Tagging v4.3.0-rc1

v4.2.1 (21 October 2021)

• Fixed issues with Adjoint ODE memory management
• Fixed included OpenCL headers

v4.2.0 (5 October 2021)

Miscellaneous:

• Updated Powell and Newton solvers to use an adjoint method to propagate derivatives in reverse mode which should result in modest speed-up. Added variadic interfaces (algebra_solver_powell_impl and algebra_solver_newton_impl). (#2421)
• Cleanup unused local typedefs. (#2505)
• Fix tbb initialization so that if STAN_THREADS is not defined then the number of threads is set to 1. (#2514)
• Bugfix for range checks not overriding STAN_THREADS. (#2530)
• Bugfix for vectorized log include order. (#2542)
• Added vectorized checks called by the stanc compiler. (#2556)
• Adds an overload for the constrain functions on whether to accumulate jacobians into log probability argument.(#2559)
• Updated algorithm for inv_Phi which is approximately 2x faster with precision of 16 digits. Based on the Fortran algorithm described in Wichura, M. J. (1988) Algorithm AS 241: The percentage points of the normal distribution. Applied Statistics, 37, 477–484.(#2566)
• Vectorized unconstrain and constraing functions. (#2574, #2580)
• Fixed generalized inverse so that it works for less than full rank symmetric matrices. (#2577)

Varmat:

• Added var<Matrix> overloads for append_row(), append_col(), rep_vector(), rep_row_vector(), to_vector(), divide(). (#2484, #2487, #2521, #2557)
• Added nested vectorized functions for the new matrix type. (#2502)
• Added support for basic slicing and dimension queries operators support var types. (#2507)
• Added several unary functions for var<Matrix> as well as division.(#2527)
• Allow accumulator to accept var<Matrix> matrix types(#2535)

Complex:

• Unary vectorized functions support containers of complex numbers(#2549)
• Added complex scalar functions get_real(), get_imag(), and to_complex.(#2554)

OpenCL:

• Added prim-only OpenCL implementations for qr_Q, qr_R, qr_thin_Q, qr_thin_R. (#2479)
• Fixed a bug for kernel generator operation block, eigenvalues_sym, eigenvectors_sym. (#2479, #2512)
• Added OpenCL implementation for cumulative_sum. (#2483)
• Fixed a bug that made OpenCL identity_matrix unusable. (#2499)
• Added reverse mode for indexing.(#2511)
• Fixed a number of bugs related to conversions of arena_matrix_cl into matrix_cl. Before this PR such a conversion invoked kernel generator and made a copy of data. Now only references to data are updated.(#2538)
• Fixes kernel generator allocating more local memory than it needed.(#2541)
• Added OpenCL implementation of sorting (sort_asc and sort_desc).(#2550)
• Bugfix OpenCL kernels so that they can no longer modify a const matrix_cl.(#2553)

v4.2.0-rc1

Tagging v4.2.0-rc1

v4.1.0 (2 June 2021)

• Added the Cash-Karp numerical integrator to improve numerical integration of ODEs with semi-stiffness and/or rapid oscillations.(#2336)
• Added the quantile function.(#2398)
• Added custom reverse mode for diag_pre_multiply() and diag_post_multiply() functions.(#2405, #2453)
• Optimized multi_normal_cholesky for non-autodiff covariance. (#2439)
• Updated Sundials to 5.7.0.(#2441)
• Improved memory safety of nested paralellism.(#2445)
• Updated TBB to 2020.3.(#2447)
• Added the STAN_NO_RANGE_CHECKS macro which turns off bounds and range checks.(#2423, #2437)
• Optimized gp_*_cov functions, especially for large amount of data.(#2464)
• Fixed compilation errors when using unsigned and long types with apply_scalar_unary.(#2469)
• Added the implementation of the loglogistic probability density function.(#2477)
• Adds reverse mode specialization for `csr_matrix_times_vector(sparse data, dense parameter).(#2462)
• Allow tbb init to set the number of threads by an argument.(#2455)
• Fixed a bug with expressions in poisson distribution functions.(#2414)
• Fixed the off by one error in set_zero_all_adjoints_nested.(#2399)
• Fixed bug with printing Eigen expressions.(#2436)
• Refactored operands and partials to avoid extra allocations.(#2418)
• Tidied up distributions C++ code.(#2352)
• Updated the integrate_1d internal interface updated in preparation for closures(#2397)
• Added docs for new contributors with a getting started guide and docs for contributing new distributions.(#2350, #2466)
• Added an ODE testing framework.(#2432)
• Replaced the finite difference approximation of the Hessian from one that is based on function calls to one that is based on gradients.(#2348)
• Updated code generation for expression tests.(#2419)
• Fixed a bug in expression tests and benchmark generation, where downloading stanc.exe did not work on Windows.(#2480)
• Varmat:
  • Add rep_* utility functions for new matrix type(#2358)
  • var<Matrix> overloads for digamma, distance, Phi, inv_Phi, Phi_approx, sqrt, tail, tgamma, rows_dot_self, fma, offset_multiplier, bessel first and second kind, beta, binary log loss, ceil, erf, erfc, exp2, expm1, falling_factorial and floor (#2362, #2378, #2396, #2461)
  • Added lb/ub/lub_constrain specializations.(#2373, #2382, #2387, #2379)
  • Added script to automatically check stanc3 signatures for varmat compatibility.(#2434)
• OpenCL:
  • Fixed OpenCL implementations of distributions mostly not working with row vectors.(#2360)
  • Added prim and rev OpenCL implementations for to_matrix, to_vector, to_row_vector, to_array_1d, to_array_2d, append_array, reverse, symmetrize_from_lower_tri, symmetrize_from_upper_tri trace.(#2377, #2383, #2388)
  • Added OpenCL functions rep_matrix, rep_vector, rep_row_vector, rep_array and identity_matrix.(#2388)
  • Added operator %.()
  • Reorganized how work is distributed between threads in generated kernels that use colwise reductions (including all distributions), significantly improving GPU preformance.(#2392)
  • Removed .triangularTranspose() member funtion from matrix_cl and TriangularMapCL enum. .triangularTranspose() is replaced by symmetrize_from_lower_tri().(#2393)
  • Added support for two dimensional reductions to kernel generator.(#2403)
  • Added OpenCL implementations for functions log_mix, log_softmax, log_sum_exp, rank, sd, softmax and ˙variance.(#2426)
  • Added OpenCL implementations for ub_constrain, lb_constrain, lub_constrain, offset_multiplier_constrain and unit_vector_constrain.(#2427)
  • Added OpenCL implementation for prod function and kernel generator operation for rowwise, colwise and 2d product.(#2433)
  • Added OpenCL implementations for functions: bernoulli_cdf, bernoulli_lcdf, bernoulli_lccdf, cauchy_cdf, cauchy_lcdf, cauchy_lccdf.(#2446)
  • Added OpenCL implementations for functions double_exponential_cdf, double exponential_lcd, double_exponential_lccdf˙, exp_mod_normal_cdf, exp_mod_normal_lcdf and exp_mod_normal_lccdf.(#2449)
  • Added OpenCL implementations for functions exponential_cdf, exponential_lcdf, exponential_lccdf, frechet_cdf, frechet_lcdf and frechet_lccdf.(#2450)
  • Added OpenCL implementations for functions gumbel_cdf, gumbel_lcdf, gumbel_lccdf, logistic_cdf, logistic_lcdf and logistic_lccdf.(#2451)
  • Added a new kernel generator operation that allows writing custom OpenCL code.(#2454)
  • Added OpenCL implementations for functions pareto_cdf, pareto_lccdf, pareto_lcdf, pareto_type_2_cdf, pareto_type_2_lccdf, and pareto_type_2_lcdf.(#2456)
  • Added OpenCL implementations for functions: rayleigh_cdf, rayleigh_lccdf, rayleigh_lcdf, skew_double_exponential_cdf, skew_double_exponential_lccdf, skew_double_exponential_lcdf and skew_double_exponential_lpdf.(#2457)
  • Added OpenCL implementations for functions lognormal_cdf, lognormal_lccdf, lognormal_lcdf, normal_cdf, normal_lccdf, normal_lcdf.(#2458)
  • Added OpenCL implementations for functions std_normal_cdf, std_normal_lccdf, std_normal_lcdf, uniform_cdf, uniform_lccdf and uniform_lcdf.(#2459)
  • Added OpenCL implementations for functions weibull_cdf, weibull_lccdf and weibull_lcdf.(#2460)
  • Removed unused OpenCL kernels and checks.(#2463)
  • Added OpenCL prim implementation for functions: gp_exponential_cov, gp_matern32_cov, matern_52_cov and both prim and rev implementation for gp_dot_prod_cov.(#2471)
  • Added reference (ref_type) for kernel generator expressions.(#2404)
  • Added typecast operation to kernel generator.(#2472)

v4.1.0-rc1 (19 May 2021)

Tagging v4.1.0-rc1

v4.0.1 (17 February 2021)

• Fixed issue with cholesky_decompose not propagating derivatives correctly .
• Fixed OpenCL implementations of distributions mostly not working with row vectors.
• Fixed handling of input expressions with reduce_sum.

v4.0.0 (26 January 2021)

New functions:

• Add symmetrize_from_lower_tri(matrix m) function to stan::math.(#2209)
• Added the Moore-Penrose generalized inverse, available with the generalized_inverse function.(#2225)
• Implement svd_U and svd_V, add gradients to singular_values.(#2286)
• Added linspaced_int_array.(#2312)

Miscellaneous improvements and bugfixes:

• Speedup reduce_sum parallelism.(#2162)
• Make gradients for negative binomial and 2F1 function more robust for boundary values.(#2175)
• Fixed problem with integrate_1d tolerances(#2183)
• Fixed a bug in check_matching_dims that prevented checking vectors of Eigen matrices of vars.(#2220)
• Updated log-likelihood calculation for ordered_probit_lpmf for increased numerical stability(#2229)
• Updated TBB makefiles to support building on M1 Macs.(#2208)
• Updated mdivide_left to avoid doing QR decomposition in reverse passes. (#2230)
• Upgraded to Eigen 3.3.9.(#2238)
• Upgraded Sundials to 5.6.1.(#2242, #2283)
• Use immediately invoked lambdas in size and range error checks to improve code caching. (#2255)
• Added a python script that can generate and run benchmarks for most of function signatures in math.(#2260)
• scalar_type_t now decays references for var_value<T> types(#2264)
• Added adjoint_of() function that accesses .adj() of vars, but analogous to value_of() also works on prim types (returning a dummy object).(#2270)
• Wishart and inverse wishart functions now check that symmetric positive definite inputs are actually symmetric positive definite.(#2281)
• Fix potential segfault when mixing reduce_sum() and print().(#2319)
• Fixed a bug in dirichlet_lpdf and multi_normal_cholesky_lpdf, where function overloads that do broadcasting produced wrong derivatives. (#2331)

Expressions:

#2093, #2131, #2133, #2136, #2138, #2139, #2150, #2151, #2186, #2190, #2205

• Generalized all remaining prim functions.
• Prim functions now return expressions where applicable.
• Removed the requirement for linear indexing from prim function
• Improved expressions testing: No longer relying on an separate file of functions that do not support expressions

OpenCL:

#2117, #2155, #2176, #2177, #2180, #2181, #2215, #2173, #2174, #2184, #2185, #2191, #2216, #2217, #2217, #2219, #2221, #2222, #2226, #2231, #2236, #2236, #2250, #2253, #2258, #2259, #2263, #2267, #2270, #2272, #2273, #2274, #2275, #2294, #2295, #2296, #2311, #2316

• Added OpenCL reverse mode support for lpdf/lpmf functions: bernoulli_lpmf, bernoulli_logit_lpmf, beta_lpdf, beta_proportion_lpdf, binomial_lpmf, cauchy_lpdf, chi_square_lpdf, double_exponential_lpdf, exp_mod_normal_lpdf, exponential_lpdf, frechet_lpdf, gamma_lpdf, gumbel_lpdf, inv_chi_square_lpdf, inv_gamma_lpdf, logistic_lpdf, lognormal_lpdf, neg_binomial_lpmf, neg_binomial_2_lpmf, neg_binomial_2_log_lpmf, normal_lpdf, pareto_lpdf, pareto_type_2_lpdf, poisson_lpmf, poisson_log_lpmf, rayleigh_lpdf, scaled_inv_chi_square_lpdf, skew_normal_lpdf, std_normal_lpdf, student_t_lpdf, uniform_lpdf and weibull_lpdf.
• Added OpenCL reverse mode support for acos, acosh, add, add_diag, asin, asinh, atan, atanh, beta, block, cbrt, ceil, cholesky_decompose, col, cols, columns_dot_product, columns_dot_self, cos, cosh, crossprod, diag_matrix, diagonal, diag_post_multiply, diag_pre_multiply, digamma, dims, distance, dot_product, dot_self, elt_divide, elt_multiply, erf, erfc, exp, exp2, expm1, fabs, floor, head, hypot, inv, inv_cloglog, inv_logit, inv_Phi, inv_sqrt, inv_square, lbeta, ldexp, lgamma, lmultiply, log, log10, log1m, log1m_exp, log1m_inv_logit, log1p, log1p_exp, log2, log_diff_exp, log_inv_logit, log_inv_logit_diff, logit, mdivide_left_tri_low, mdivide_right_tri_low, mean, multiply, multiply_log, num_elements, Phi, Phi_approx, pow, round, row, rows, rows_dot_product, rows_dot_self, segment, sin, sinh, size, sqrt, square, squared_distance, sub_col, sub_row, subtract, sum, tail, tan, tanh, tcrossprod, tgamma, transpose and trunc.
• Reduced amount of copying when using OpenCL. CPUs and integrated GPUs can use host memory in place. Transferring data to discrete GPUs can avoid one copy to pinned memory on host side if the new pinned_matrix class is used. Depending on the OPenCL implementation, optimization for CPUs and Discrete GPUs may also require use of this class. (#2219)
• Improved kernel generator: simplified writing of broadcasting tests, fixed a bug when using same operations on different sets of unique matrices, fixed check_cl, extended support for integer arguments, added support for kernel expressions returning a scalar, added compound assignment operators, made transpose kernel generator operation assignable.
• Bugfixed arena_matrix_cl so it can be assigned a matrix_cl.(#2270)

Varmat:

• Added varmat implementations of cholesky_decompose, columns_dot_self, determinant, dot_self, inverse, log_determinant, matrix_power, multiply_lower_tri_self_transpose, and tcrossprod, add, operator+, operator-, quad_form, trace_quad_form, transpose (member function), variance, sd, log_softmax, log_sum_exp, divide, trace_gen_quad_form, dot_product, columns_dot_product, rows_dot_product, squared_distance, mdivide_left_spd, mdivide_left_tri, mdivide_left, log_determinant_spd, mdivide_left_ldlt, mdivide_right_ldlt, log_determinant_ldlt, trace_gen_inv_quad_form_ldlt, trace_inv_quad_form_ldlt (#2105, #2106, #2115, #2163, #2164, #2168, #2169, #2171, #2172, #2196, #2199, #2212, #2213, #2230, #2232, #2266, #2280, #2305)
• Adds var_value<Matrix> overloads for array and column vector converters.(#2278)
• Make multivariate distributions work with varmat(#2284)
• Adds sequence views for var<matrix> to make some of the distributions var matrix compatible(#2292)
• to_var_value and from_var_value now work with std::vector types(#2299)
• Add more methods for taking blocks of var matrices.(#2188)
• Updating matrix constrains to work with varmart(#2254)
• Adds arc trig functions for var<matrix> along several other unary operators (#2256)

v3.5.0-rc1 (19 January 2021)

Tagging v3.5.0-rc1