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matlab_-_help [2012/11/12 18:45] (current)
jochen created
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 +====== Matlab - help ======
 +Given the great range of functions that are already built into Matlab as well as the fact that additional functions can be added to the environment by means of "​toolboxes"​ (folders containing sets of functions that depend on one another and that, as a whole, can be considered a program or functionality set of its own), Matlab offers a rudimentary but extremely helpful way for the user to inquire about available functions.
  
 +===== The help function =====
 +On the command line, you can enter just "​help"​ (which calls the internal help function provided by Matlab). This will produce a list containing hyperlinks that can be clicked on, with one entry per installed toolbox, which includes the toolboxes that come with Matlab itself. Important toolboxes (and associated functions) are:
 +
 +  * **codetools** (functions to edit and work with user-written code files):
 +    * edit (invokes a fully functional editor with syntax highlighting and step-by-step debugger)
 +    * keyboard, dbstop, dbclear, dbstep, dbup, dbdown, dbstack, dbcont (debugging functions, see [[Matlab - debugging|debugging section]])
 +  * **datafun** (functions to calculate basic statistics and transform data):
 +    * max, min (maximum and minimum over one dimension of an array or between two arrays)
 +    * mean, median, mode (central tendency over one dimension of an array)
 +    * var, std (variance and standard deviation)
 +    * sort (sorting of elements, can be used to sort associated lists)
 +    * sum, cumsum, prod, cumprod (''​optionally cumulative''​ sum and product over one dimension of an array)
 +    * diff (discrete derivative)
 +    * corrcoef (correlation coefficient)
 +    * cov (covariance matrix)
 +    * conv, convn (convolution)
 +    * detrend (detrending)
 +    * fft, fftn, ifft, ifftn, fftshift (fast-fourier-transform,​ FFT functions)
 +  * **elfun** (elementary math functions)
 +    * sin, sinh, asin, asinh, cos, cosh, acos, acosh, tan, tanh, atan, atan2, atanh (and others, trigonometrical functions)
 +    * exp, log, log10, log2, pow2 (exponential/​logarithm functions)
 +    * sqrt (square root)
 +    * abs (absolute value)
 +    * complex, real, imag (complex value generation/​creation/​inspection)
 +    * fix, round, floor, ceil (rounding)
 +    * mod, rem (modulus, remainder)
 +    * sign (numeric sign)
 +  * **elmat** (elementary matrix functions)
 +    * zeros, ones (create matrices to reserve memory with neutral element)
 +    * repmat (replicate value, vector, or matrix N-times in several dimensions)
 +    * size, length, numel, ndims (size of array)
 +    * cat (catenate arrays in a desired dimension)
 +    * permute (reordering dimensions)
 +    * reshape (reshape array, dimension folding/​splitting)
 +    * squeeze (remove 1-size dimensions)
 +    * find (convert array into list of non-zero/​true values)
 +    * sub2ind, ind2sub (converting matrix addressing options)
 +    * ndgrid (create indexing arrays)
 +  * **general** (general purpose functions)
 +    * who, whos, clear (workspace manipulation/​inspection)
 +    * load, save (variable to/from disk operations)
 +    * which (resolve symbol to variable or function name, incl. location, also files)
 +    * path, addpath, rmpath, savepath, pathtool, rehash (path manipulation functions)
 +    * diary (output console content, i.e. commands and returned values, into file)
 +    * format (format default output options)
 +    * cd, pwd (change/​display current directory)
 +    * dir (list directory contents)
 +    * ! (exclamation point: run system command)
 +  * **lang** (language help!)
 +    * global, persistent (variable memory storage type declaration)
 +    * function (declare/​begin function)
 +    * if, else, elseif (conditional execution of statements)
 +    * for (pre-defined loops)
 +    * while (conditional loops)
 +    * break, continue (terminate loop, skip rest of loop cycle)
 +    * switch, case, otherwise (expression based selection of code)
 +    * try, catch (internal error handling)
 +    * end (terminates control flow structures: if, for, while, switch, try)
 +    * error (throw exception/​error)
 +    * return (leave function)
 +    * parfor, spmd (parallel processing keywords, end also terminates)
 +    * eval, feval, evalin, builtin, assignin (evaluation of function by name/​handle)
 +    * exist (test if file/​variable exists)
 +    * nargin, varargin, nargout, varargout (argument handling)
 +    * ans (default variable if output is not suppressed)
 +  * **matfun** (matrix functions)
 +    * rank, det, trace (rank, determinant,​ trace of matrix)
 +    * inv, pinv (inverse, pseudo-inverse)
 +    * eig, svd (eigenvalues/​eigenvectors,​ SVD)
 +  * **ops** (operators)
 +  * **polyfun** (polynomial functions)
 +    * interp, interpn (interpolation)
 +  * **randfun** (random number functions)
 +    * rand, randn (uniform, and normally distributed numbers)
 +    * randperm (random permutation)
 +  * **strfun** (string-manipulation functions)
 +    * char (convert to character)
 +    * cellstr (convert 2D character array into list of strings)
 +    * deblank (remove trailing blank characters of string/s)
 +    * strcmp, strcmpi (string comparison)
 +    * strfind (find string in another)
 +    * strrep (replace one string with another)
 +    * regexp, regexpi, regexprep (regular expression match/​replacing)
 +    * lower, upper (convert character case)
 +    * num2str, str2num, str2double (convert between numbers and strings)
 +    * sprintf (format strings)
 +  * **timefun** (time-related functions)
 +    * now (return internal clock value)
 +    * date, datenum, datestr, datevec (date related functions)
 +    * tic, toc (timing functions)
 +    * pause (waiting)
 +
 +To get additional help on any of these functions, simply enter ''​**help FUNCTION**''​.
 +
 +===== Online help =====
 +In addition to the help available within Matlab, Mathworks offers an online version of the help (which contains further examples and tips). For instance, this the online help article for the [[http://​www.mathworks.com/​help/​matlab/​ref/​strfind.html|strfind]] function.
matlab_-_help.txt ยท Last modified: 2012/11/12 18:45 by jochen