• Armadillo is an open-source C++ linear algebra library (matrix maths) aiming towards a good balance between speed and ease of use. Integer, floating point and complex numbers are supported, as well as a subset of trigonometric and statistics functions.
   
• Various matrix decompositions are provided through optional integration with LAPACK, or one of its high performance drop-in replacements (such as the multi-threaded MKL or ACML libraries).
   
• A delayed evaluation approach is employed (during compile time) to combine several operations into one and reduce (or eliminate) the need for temporaries. This is accomplished through recursive templates and template meta-programming.
   
• This library is useful if C++ has been decided as the language of choice (due to speed and/or integration capabilities), rather than another language like Matlab ® or Octave. It is distributed under a license that is useful in both open-source and commercial contexts.
   
• Armadillo is primarily developed at NICTA (Australia), with contributions from around the world.
   
• Download latest version
   

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NEWS

2011-12-15		Recent papers developed with the aid of Armadillo:   Shadow detection: A survey and comparative evaluation of recent methods Pattern Recognition, Vol. 45, No. 4, 2012.   MRF-based Background Initialisation for Improved Foreground Detection in Cluttered Surveillance Videos ACCV, Lecture Notes in Computer Science (LNCS), Vol. 6494, 2011.   Patch-based Probabilistic Image Quality Assessment for Face Selection and Improved Video-based Face Recognition Biometrics Workshop, IEEE Conf. Computer Vision and Pattern Recognition, 2011   A Low-Complexity Algorithm for Static Background Estimation from Cluttered Image Sequences in Surveillance Contexts Eurasip Journal on Image and Video Processing, 2011
2011-12-12		Version 2.4.2 clarified documentation for .reshape() added .resize() fix for vector initialisation
2011-12-05		Version 2.4.0   “Loco Lounge Lizard” added shorter forms of transposes: .t() and .st() added optional use of 64 bit indices, allowing matrices to have more than 4 billion elements added experimental support for C++11 initialiser lists faster pinv() faster inplace transpose faster handling of expressions with diagonal views fixes for handling expressions with aliasing and submatrices fixes for linking on Ubuntu and Debian systems fixes for inconsistencies in interactions between matrices and cubes refactored code to eliminate warnings when using the Clang C++ compiler .print_trans() and .raw_print_trans() are deprecated
2011-08-27		Version 2.2.3 fix for speed issue in as_scalar()
2011-08-02		Version 2.2.1   “Blue Skies Debauchery” faster multiplication of small matrices faster trans() faster handling of submatrices by norm() added economical singular value decomposition: svd_econ() added circ_toeplitz() added .is_colvec() & .is_rowvec() fixes for handling of complex numbers by cov(), cor(), running_stat_vec
2011-07-16		Version 2.0.2 fix for handling of conjugate transpose by as_scalar() fix for handling of aliasing by diagmat() fix for handling of empty matrices by symmatu()/symmatl()
2011-06-29		Version 2.0.0   “Carnivorous Sugar Glider” faster multiplication of tiny matrices (≤ 4x4) faster compound expressions containing submatrices faster inverse of symmetric positive definite matrices faster element access for fixed size matrices added handling of arbitrarily sized empty matrices (eg. 5x0) added loading & saving of matrices as CSV text files added .count() member function to running_stat and running_stat_vec added syl(), strans(), symmatu()/symmatl() added submatrices of submatrices det(), inv() and solve() can be forced to use more precise algorithms for tiny matrices (≤ 4x4) htrans() has been deprecated; use trans() instead API change: trans() now takes the complex conjugate when transposing a complex matrix API change: .is_vec() now outputs true for empty vectors (eg. 0x1) API change: forms of chol(), eig_sym(), eig_gen(), inv(), lu(), pinv(), princomp(), qr(), solve(), svd(), syl() that do not return a bool indicating success now throw std::runtime_error exceptions when failures are detected API change: princomp_cov() has been removed; eig_sym() in conjunction with cov() can be used instead API change: set_log_stream() & get_log_stream() have been replaced by set_stream_err1() & get_stream_err1()

↓ earlier news ↓

2011-04-18		Version 1.2.0   “Unscrupulous Carbon Emitter” Added ability to use Blas & Lapack libraries with capitalised function names Reduction of pedantic compiler warnings
2011-03-31		Version 1.1.92   “Jurassic Barbecue” Bugfix in cor() Automatic installation now requires CMake ≥ 2.6
2011-03-22		Version 1.1.90   “Inside Job” Added .min() & .max(), which can provide the extremum's location More robust mean(), var(), stddev()
2011-03-10		Version 1.1.8   “Kangaroo Steak” Added floor() and ceil() Added “not a number”: math::nan() Added infinity: math::inf() Added standalone is_finite() Faster min(), max(), mean() Bugfix for a corner case with NaNs in min() and max()
2011-03-02		Version 1.1.6   “Baby Carpet Shark” fixed size matrices and vectors can use auxiliary (external) memory .in_range() can use span() arguments subfields can use span() arguments
2011-02-18		Version 1.1.4   “Manta Lodge” Faster sort() Updated installation to detect recent versions of Intel's MKL Added interpretation of arbitrary "flat" subcubes as matrices
2011-02-02		Version 1.1.2   “Flood Kayak” Faster prod() Faster solve() for compound expressions Fix for compilation using GCC's C++0x mode Fix for matrix handling by subcubes
2010-12-23		Version 1.1.0   “Climate Vandal” Extended submatrix views, including access to elements whose indices are specified in a separate vector Added handling of raw binary files by save/load functions Added cumsum() Added interpretation of matrices as triangular via trimatu()/trimatl() Faster solve() and inv() via explicit handling of triangular matrices The stream for logging of errors and warnings can now be changed
2010-11-23		Version 1.0.0   “Antipodean Antileech” After 2½ years of collaborative development, we are proud to release the 1.0 milestone version Many thanks are extended to all contributors and bug reporters
2010-11-11		Version 0.9.92   “Wall Street Gangster” Fixes for compilation issues under the Intel C++ compiler Added matrix norms
2010-10-14		Version 0.9.90   “Water Dragon” Added unsafe_col() Speedups and bugfixes in lu() Minimisation of pedantic compiler warnings
2010-09-28		Overview Tech Report An overview of Armadillo's functionality is available in a NICTA tech report
2010-09-21		Version 0.9.80   “Chihuahua Muncher” Added join_slices(), insert_slices(), shed_slices() Added in-place operations on diagonals Various speedups due to internal architecture improvements
2010-09-01		Version 0.9.70   “Subtropical Winter Safari” Added template based size specification Added insertion of rows & columns Added deletion of rows & columns Added set_imag() & set_real() Added in_range() Added is_empty() Various speedups, mainly in expressions involving submatrices Fixes for a few corner cases
2010-08-04		Version 0.9.60   “Killer Bush Turkey” More flexible reshape(), allowing significantly different matrix sizes Added matrix initialisation via the << operator Fixes for compilation issues under Mac OS X with GCC 4.2/4.0 hybrid
2010-07-14		Version 0.9.52   “Monkey Wrench” Bugfixes for saving complex cubes Workarounds to remove warnings under certain dodgy compilers
2010-07-07		Version 0.9.50   “Flying Spaghetti Monster” Faster compilation by omitting Boost where possible Faster insertion into submatrices More accurate linspace() Deprecated rand() in favour of randu() Modified load() & save() to print warnings Added quiet_load() & quiet_save() Added conversions to/from std::vector Added convolution operation: conv() Added toeplitz() Added detection of MKL & ACML during installation Added MSVC project files for compiling examples
2010-06-02		Version 0.9.10   “Chilli Espresso” Speedups for find() and relational operators Speedups for expressions involving mixed matrix types More consistent success indication by decomposition functions
2010-05-14		Version 0.9.8   “Dog's Breakfast” Added handling of interactions between complex scalars and non-complex matrices Minor bugfixes for compilation issues under certain compilers
2010-04-28		Version 0.9.6   “Chimerican Climate Cabal” Faster randn() Expanded norm() to handle max and min norms Added join_rows()/join_cols(), find() and STL-style iterators
2010-03-16		Version 0.9.4   “Cat Herder” Added cross() Bugfixes for inplace addition of particular vector multiplication expressions
2010-03-03		NICTA at CeBIT in Hannover Armadillo is used in NICTA's face-based identity inference product demonstrators (part of the Advanced Surveillance project). See this page for more info on NICTA's presence at CeBIT.
2010-03-02		Version 0.9.2   “Cuban Cigar” Minor speedups Added princomp_cov() Bugfixes in complex-number versions of several functions
2010-02-05		Version 0.9.0   “Retoxed Feral” Extended and overhauled expression evaluation framework, for more efficient handling of compound expressions There is a small but important API change -- see the docs for details Added a conversion table between Matlab/Octave and Armadillo syntax Added saving/loading of matrices using streams Added log_det(), princomp(), fliplr(), flipud() More accurate var() and stddev()
2010-01-27		Version 0.8.2   “Colombian Coffee” Added as_scalar(), for forward compatibility with 0.9.x Miscellaneous bugfixes
2009-12-14		Version 0.8.0   “Restless Critter” Added pinv(), rank(), kron(), prod(), eps(), shuffle() Added ‘running_stat_vec’ class, for on-the-fly statistics of vectors Improvements and bugfixes in handling of submatrix views Speedups for some compound expressions Initial support for dodgy compilers
2009-10-26		Version 0.7.2   “Tequila Sunrise” Added covariance and correlation functions Added simpler form of lu() Faster repmat() and reshape() Better detection of external libraries during installation
2009-10-07		Version 0.7.0   “Unshackled Mongrel” Added the Cube class (aka "3D matrix" or a set of matrices with contiguous memory) Added creation of Mat instances using auxiliary memory Added repmat() Bugfixes for det() and lu()
2009-06-25		Version 0.6.12   “Ye Greene Beaste” Added raw_print() and a collection of physical constants Code cleanup for better conformance to the C++ standard Miscellaneous documentation and installation improvements
2009-05-20		Version 0.6.11 Bug fix for solve() when using complex numbers More elaborate class destructors for better debugging of user code Miscellaneous documentation and installation improvements
2009-05-02		Version 0.6.10 Added eigen decomposition of generic (non-symmetric) matrices Function eig() renamed to eig_sym()
2009-04-23		Version 0.6.8 Better installation on MacOS X Colour PPM images can now be loaded as fields of matrices
2009-04-08		Version 0.6.6 Better installation on 64 bit systems, especially when using CMake 2.6 Fields of strings can be now loaded & saved as plain text files Bug fix for template detection of combined multiply and addition operations
2009-04-02		Version 0.6.4 Added running_stat class for on-the-fly statistics Renamed main classes for better code readability Performance tweaks, which can result in speedups of 30% for small matrices
2009-03-26		Version 0.6.2 Fixes for interactions between matrices with different element types
2009-03-24		Version 0.6.0 Added functionality: solve(), for solving systems of linear equations svd(), singular value decomposition expressions can now have mixed matrix types complex number versions of statistics functions reworked operators, providing more flexibility Bug fixes: sign of scalar produced by det() handling of single row and column submats by statistics functions
2009-03-11		Version 0.5.2 Added functionality: subfields sort_index() Bug fixes: pow() applied to integer matrices (gcc < 4.3) multiplication of submats with a scalar missing division operators
2009-03-09		Version 0.5.0 Added functionality: Cholesky and QR decompositions element-wise division comparison operators more elegant restriction of template parameters Bug fixes: handling of diagonal matrices created from vectors compilation of examples under MacOS X Other changes: faster matrix inverse license change to LGPL v3+ updated and re-arranged documentation easier installation when using the .tar.gz package
2009-01-28		Version 0.4.0 Bug fixes and added functionality: easier configuration and installation statistics functions more functions for handling complex numbers
2009-01-16		Version 0.3.0 Added functionality: handling of complex numbers as well as other types added trigonometric functions
2008-12-23		Version 0.2.1 Fixes for several minor bugs.
2008-12-12		Version 0.2.0 More functionality, bug fixes and improved user documentation.
2008-11-04		Version 0.1.0 Initial proof-of-concept release.