# GNU Octave Version 3.2

## Summary of important user-visible changes

June 5, 2009

News for version 5 4.4 4.2 4 3.8 3.6 3.4 3.2 3 2 1 (Release History)

** Compatibility with Matlab graphics has been improved. The hggroup object and associated listener callback functions have been added allowing the inclusion of group objects. Data sources have been added to these group objects such that x = 0:0.1:10; y = sin (x); plot (x, y, "ydatasource", "y"); for i = 1 : 100 pause(0.1) y = sin (x + 0.1 * i); refreshdata(); endfor works as expected. This capability has be used to introduce stem-series, bar-series, etc., objects for better Matlab compatibility. ** New graphics functions: addlistener ezcontour gcbo refresh addproperty ezcontourf ginput refreshdata allchild ezmesh gtext specular available_backends ezmeshc intwarning surfl backend ezplot ishghandle trisurf cla ezplot3 isocolors waitforbuttonpress clabel ezpolar isonormals comet ezsurf isosurface dellistener findall linkprop diffuse gcbf plotmatrix ** New experimental OpenGL/FLTK based plotting system. An experimental plotting system based on OpenGL and the FLTK toolkit is now part of Octave. This backend is disabled by default. You can switch to using it with the command backend ("fltk") for all future figures or for a particular figure with the command backend (h, "fltk") where "h" is a valid figure handle. Please note that this backend does not yet support text objects. Obviously, this is a necessary feature before it can be considered usable. We are looking for volunteers to help implement this missing feature. ** Functions providing direct access to gnuplot have been removed. The functions __gnuplot_plot__, __gnuplot_set__, __gnuplot_raw__, __gnuplot_show__, __gnuplot_replot__, __gnuplot_splot__, __gnuplot_save_data__ and __gnuplot_send_inline_data__ have been removed from Octave. These function were incompatible with the high level graphics handle code. ** The Control, Finance and Quaternion functions have been removed. These functions are now available as separate packages from http://octave.sourceforge.net/packages.html and can be reinstalled using the Octave package manager (see the pkg function). ** Specific sparse matrix functions removed. The following functions, which handled only sparse matrices have been removed. Instead of calling these functions directly, you should use the corresponding function without the "sp" prefix. spatan2 spcumsum spkron spprod spchol spdet splchol spqr spchol2inv spdiag splu spsum spcholinv spfind spmax spsumsqk spcumprod spinv spmin ** Improvements to the debugger. The interactive debugging features have been improved. Stopping on statements with dbstop should work correctly now. Stepping into and over functions, and stepping one statement at a time (with dbstep) now works. Moving up and down the call stack with dbup and dbdown now works. The dbstack function is now available to print the current function call stack. The new dbquit function is available to exit the debugging mode. ** Improved traceback error messages. Traceback error messages are much more concise and easier to understand. They now display information about the function call stack instead of the stack of all statements that were active at the point of the error. ** Object Oriented Programming. Octave now includes OOP features and the user can create their own class objects and overloaded functions and operators. For example, all methods of a class called "myclass" will be found in a directory "@myclass" on the users path. The class specific versions of functions and operators take precedence over the generic versions of these functions. New functions related to OOP include class inferiorto isobject loadobj methods superiorto See the Octave manual for more details. ** Parsing of Command-style Functions. Octave now parses command-style functions without needing to first declare them with "mark_as_command". The rules for recognizing a command-style function calls are * A command must appear as the first word in a statement, followed by a space. * The first character after the space must not be '=' or '(' * The next token after the space must not look like a binary operator. These rules should be mostly compatible with the way Matlab parses command-style function calls and allow users to define commands in .m files without having to mark them as commands. Note that previous versions of Octave allowed expressions like x = load -text foo.dat but an expression like this will now generate a parse error. In order to assign the value returned by a function to a variable, you must use the normal function call syntax: x = load ("-text", "foo.dat"); ** Block comments. Commented code can be between matching "#{" and "#}" or "%{" and "%}" markers, even if the commented code spans several line. This allows blocks code to be commented, without needing to comment each line. For example, function [s, t] = func (x, y) s = 2 * x; #{ s *= y; t = y + x; #} endfunction the lines "s *= y;" and "t = y + x" will not be executed. ** Special treatment in the parser of expressions like "a' * b". In these cases the transpose is no longer explicitly formed and BLAS libraries are called with the transpose flagged, significantly improving performance for these kinds of operations. ** Single Precision data type. Octave now includes a single precision data type. Single precision variables can be created with the "single" command, or from functions like ones, eye, etc. For example, single (1) ones (2, 2, "single") zeros (2, 2, "single") eye (2, 2, "single") Inf (2, 2, "single") NaN (2, 2, "single") NA (2, 2, "single") all create single precision variables. For compatibility with Matlab, mixed double/single precision operators and functions return single precision types. As a consequence of this addition to Octave the internal representation of the double precision NA value has changed, and so users that make use of data generated by Octave with R or visa-versa are warned that compatibility might not be assured. ** Improved array indexing. The underlying code used for indexing of arrays has been completely rewritten and indexing is now significantly faster. ** Improved memory management. Octave will now attempt to share data in some cases where previously a copy would be made, such as certain array slicing operations or conversions between cells, structs and cs-lists. This usually reduces both time and memory consumption. Also, Octave will now attempt to detect and optimize usage of a vector as a stack, when elements are being repeatedly inserted at/removed from the end of the vector. ** Improved performance for reduction operations. The performance of the sum, prod, sumsq, cumsum, cumprod, any, all, max and min functions has been significantly improved. ** Sorting and searching. The performance of sort has been improved, especially when sorting indices are requested. An efficient built-in issorted implementation was added. sortrows now uses a more efficient algorithm, especially in the homegeneous case. lookup is now a built-in function performing a binary search, optimized for long runs of close elements. Lookup also works with cell arrays of strings. ** Range arithmetics For some operations on ranges, Octave will attempt to keep the result as a range. These include negation, adding a scalar, subtracting a scalar, and multiplying by a scalar. Ranges with zero increment are allowed and can be constructed using the built-in function `ones'. ** Various performance improvements. Performance of a number of other built-in operations and functions was improved, including: * logical operations * comparison operators * element-wise power * accumarray * cellfun * isnan * isinf * isfinite * nchoosek * repmat * strcmp ** 64-bit integer arithmetic. Arithmetic with 64-bit integers (int64 and uint64 types) is fully supported, with saturation semantics like the other integer types. Performance of most integer arithmetic operations has been improved by using integer arithmetic directly. Previously, Octave performed integer math with saturation semantics by converting the operands to double precision, performing the operation, and then converting the result back to an integer value, truncating if necessary. ** Diagonal and permutation matrices. The interpreter can now treat diagonal and permutation matrices as special objects that store only the non-zero elements, rather than general full matrices. Therefore, it is now possible to construct and use these matrices in linear algebra without suffering a performance penalty due to storing large numbers of zero elements. ** Improvements to fsolve. The fsolve function now accepts an option structure argument (see also the optimset function). The INFO values returned from fsolve have changed to be compatible with Matlab's fsolve function. Additionally, fsolve is now able to solve overdetermined systems, complex-differentiable complex systems, systems with a sparse jacobian and can work in single precision if given single precision inputs. It can also be called recursively. ** Improvements to the norm function. The norm function is now able to compute row or column norms of a matrix in a single call, as well as general matrix p-norms. ** New functions for computing some eigenvalues or singular values. The eigs and svds functions have been included in Octave. These functions require the ARPACK library (now distributed under a GPL-compatible license). ** New QR and Cholesky factorization updating functions. choldelete cholshift qrdelete qrshift cholinsert cholupdate qrinsert qrupdate ** New quadrature functions. dblquad quadgk quadv triplequad ** New functions for reading and writing images. The imwrite and imread functions have been included in Octave. These functions require the GraphicsMagick library. The new function imfinfo provides information about an image file (size, type, colors, etc.) ** The input_event_hook function has been replaced by the pair of functions add_input_event_hook and remove_input_event_hook so that more than one hook function may be installed at a time. ** Other miscellaneous new functions. addtodate hypot reallog bicgstab idivide realpow cellslices info realsqrt cgs interp1q rectint command_line_path isdebugmode regexptranslate contrast isfloat restoredefaultpath convn isstrprop roundb cummin log1p rundemos cummax lsqnonneg runlength datetick matlabroot saveobj display namelengthmax spaugment expm1 nargoutchk strchr filemarker pathdef strvcat fstat perl subspace full prctile symvar fzero quantile treelayout genvarname re_read_readline_init_file validatestring histc ** Changes to strcat. The strcat function is now compatible with Matlab's strcat function, which removes trailing whitespace when concatenating character strings. For example strcat ('foo ', 'bar') ==> 'foobar' The new function cstrcat provides the previous behavior of Octave's strcat. ** Improvements to the help functions. The help system has been mostly re-implemented in .m files to make it easier to modify. Performance of the lookfor function has been greatly improved by caching the help text from all functions that are distributed with Octave. The pkg function has been modified to generate cache files for external packages when they are installed. ** Deprecated functions. The following functions were deprecated in Octave 3.0 and will be removed in Octave 3.4 (or whatever version is the second major release after 3.0): beta_cdf geometric_pdf pascal_pdf beta_inv geometric_rnd pascal_rnd beta_pdf hypergeometric_cdf poisson_cdf beta_rnd hypergeometric_inv poisson_inv binomial_cdf hypergeometric_pdf poisson_pdf binomial_inv hypergeometric_rnd poisson_rnd binomial_pdf intersection polyinteg binomial_rnd is_bool setstr chisquare_cdf is_complex struct_contains chisquare_inv is_list struct_elements chisquare_pdf is_matrix t_cdf chisquare_rnd is_scalar t_inv clearplot is_square t_pdf clg is_stream t_rnd com2str is_struct uniform_cdf exponential_cdf is_symmetric uniform_inv exponential_inv is_vector uniform_pdf exponential_pdf isstr uniform_rnd exponential_rnd lognormal_cdf weibcdf f_cdf lognormal_inv weibinv f_inv lognormal_pdf weibpdf f_pdf lognormal_rnd weibrnd f_rnd meshdom weibull_cdf gamma_cdf normal_cdf weibull_inv gamma_inv normal_inv weibull_pdf gamma_pdf normal_pdf weibull_rnd gamma_rnd normal_rnd wiener_rnd geometric_cdf pascal_cdf geometric_inv pascal_inv The following functions are now deprecated in Octave 3.2 and will be removed in Octave 3.6 (or whatever version is the second major release after 3.2): create_set spcholinv spmax dmult spcumprod spmin iscommand spcumsum spprod israwcommand spdet spqr lchol spdiag spsum loadimage spfind spsumsq mark_as_command spinv str2mat mark_as_rawcommand spkron unmark_command spatan2 splchol unmark_rawcommand spchol split spchol2inv splu See NEWS.3 for old news.