MATLAB functions

Logical operators.

any - True if any element of vector is nonzero

all - True if all elements of vector are nonzero

Set operators.

union - Set union.

unique - Set unique.

intersect - Set intersection.

setdiff - Set difference.

setxor - Set exclusive-or.

ismember - True for set member.

Sparse Matrices

find - Find indices and values of nonzero elements

nnz - Number of nonzero matrix elements

nonzeros - Nonzero matrix elements

Random Number Generators

See also “Random Number Generators” in MATLAB HELP.

randperm - Random permutation

randperm(n) returns a random permutation of the integers 1:n.

randn - Normally distributed random numbers

RANDN(N) returns an N-by-N matrix containing pseudo-random values drawn from a normal distribution with mean zero and standard deviation one.

rand - Uniformly distributed pseudorandom numbers

RAND(N) returns a N-by-N matrix containing pseudo-random, scalar value drawn from a uniform distribution on the unit interval

mvnrnd - Multivariate normal random numbers

Rounding and Remainder

ceil - Round toward infinity

fix - Round toward zero floor - Round toward minus infinity

idivide - Integer division with rounding option

mod - Modulus after division

rem - Remainder after division

round - Round to nearest integer

Dynamic expression and function

eval - Execute string containing MATLAB® expression

feval - Evaluate function

Arrays and Matrices – Basic Information

isempty - Determine whether array is empty

isequal - Test arrays for equality

isfinite - Array elements that are finite

isinf - Array elements that are infinite

isnan - Array elements that are NaN

length - Length of vector

max - Largest elements in array

min - Smallest elements in array

ndims - Number of array dimensions

numel - Number of elements in array or subscripted array

expression

size - Array dimensions

Arrays and Matrices – Elementary Matrices and Arrays

diag - Diagonal matrices and diagonals of matrix

eye - Identity matrix

ones - Create array of all ones

zeros - Create array of all zeros

Arrays and Matrices – Array Manipulation

repmat - Replicate and tile array

reshape - Reshape array

sort - Sort array elements in ascending or descending order

sortrows - Sort rows in ascending orde

Linear Algebra – Matrix Analysis

cond - Condition number with respect to inversion

The condition number of a matrix measures the sensitivity of the solution of a system of linear equations to errors in the data. It gives an indication of the accuracy of the results from matrix inversion and the linear equation solution. Values of cond(X) and cond(X,p) near 1 indicate a well-conditioned matrix.

rcond - Matrix reciprocal condition number estimate

c = rcond(A) returns an estimate for the reciprocal of the condition of A in 1-norm using the LAPACK condition estimator. If A is well conditioned, rcond(A) is near 1.0. If A is badly conditioned, rcond(A) is near 0.0. Compared to cond, rcond is a more efficient, but less reliable, method of estimating the condition of a matrix.

condeig - Condition number with respect to eigenvalues

Large condition numbers imply that A is near a matrix with multiple eigenvalue

det - Matrix determinant

norm - Vector and matrix norms

rank - Rank of matrix

sqrtm - Matrix square root

Linear Algebra – Linear Equations

chol - Cholesky factorization

lu - LU matrix factorization

svd - Singular value decomposition

qr - Orthogonal-triangular decomposition

qz - QZ factorization for generalized eigenvalues

Linear Algebra – Inverse

inv - Matrix inverse

pinv - Moore-Penrose pseudoinverse of matrix

Math Constants

eps - Floating-point relative accuracy

I - Imaginary unit

Inf - Infinity

intmax - Largest value of specified integer type

intmin - Smallest value of specified integer type

j - Imaginary unit

NaN - Not-a-Number

pi - Ratio of circle's circumference to its diameter, π

realmax - Largest positive floating-point number

realmin - Smallest positive normalized floating-point number

Descriptive Statistics

corrcoef - Correlation coefficients

cov - Covariance matrix

max - Largest elements in array

mean - Average or mean value of array

median - Median value of array

min - Smallest elements in array

mode - Most frequent values in array std - Standard deviationvarVarianc

Strings

sprintf - Write formatted data to string

sscanf - Read formatted data from string

strcat - Concatenate strings horizontally

strcmp,strcmpi - Compare strings strmatch - Find possible matches for string

strncmp, strncmpi - Compare first n characters of strings

str2num - Convert string to number

num2str - Convert number to string

Logical

all - Determine whether all array elements are nonzero

any - Determine whether any array elements are nonzero

find - Find indices and values of nonzero elements

File Name Construction

filemarker - Character to separate file name and internal function name

fileparts - Parts of file name and path

filesep - Directory separator for current platform

fullfile - Build full filename from parts

tempdir - Name of system's temporary directory

tempname - Unique name for temporary file

Graphics -Printing and Exporting

See also “Printing and Exporting” in MATLAB HELP.

saveas - Save figure or Simulink block diagram using specified format

print - Print figure or save to file and configure printer defaults.

Graphics - getting and changing properties

gca - Current axes handle

h = gca returns the handle to the current axes for the current figure. See also “Axes Properties” in MATLAB HELP, which can be modified using get and set.

gcf- Current figure handle

h = gcf returns the handle of the current figure. See also “Figure Properties” in MATLAB HELP, which can be modified using get and set.

get- Query object properties

Example: 
get(get(gca,'Children'),'HandleVisibility');

set - Set object properties

Example: 
set(gca,'Color','b');


Graphics – plotting function

fplot - Plot function between specified limits

fplot(fun,limits)plotsfunbetween the limits specified bylimits.limitsis a vector specifying thex-axis limits ([xminxmax]), or thex- andy-axes limits, ([xminxmaxyminymax]).

fun must be

The name of an M-file function
A string with variable x that may be passed to eval , such as 'sin(x)' , 'diric(x,10)' , or '[sin(x),cos(x)]'
A function handle for an M-file function or an anonymous function


Graphics – Annotating

See also “Annotating Graphs” in MATLAB HELP.

text- Text annotation

TEXT(X,Y,'string') adds the text in the quotes to location (X,Y)on the current axes.

legend- Display legend

Development Environment

clc- Clear Command Window

diary- Save session to file

clear- Remove items from workspace, freeing up system memory

exist- Check existence of variable, function, directory, or Java™ programming language class

isfield- Determine whether input is structure array field

who, whos- List variables in workspace

profile- Profile execution time for function

disp- Display text or array

datestr- Convert date and time to string format. see also "Date and Time Functions".

mfilename- Name of currently running M-file

run- Run script that is not on current path
run('../PROGLIB/stprtool/stprpath')