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MATLAB is an interactive program for numerical computation and data visualization. You can enter a command by typing it at the MATLAB prompt ”>>” on the Command Window.
In this section, we will provide lists of commonly used general MATLAB commands.
Commands for Managing a Session
MATLAB provides various commands for managing a session. The following table provides all such commands −
| Command | Purpose |
|---|---|
| clc | Clears command window. |
| clear | Removes variables from memory. |
| exist | Checks for existence of file or variable. |
| global | Declares variables to be global. |
| help | Searches for a help topic. |
| lookfor | Searches help entries for a keyword. |
| quit | Stops MATLAB. |
| who | Lists current variables. |
| whos | Lists current variables (long display). |
Commands for Working with the System
MATLAB provides various useful commands for working with the system, like saving the current work in the workspace as a file and loading the file later.
It also provides various commands for other system-related activities like, displaying date, listing files in the directory, displaying current directory, etc.
The following table displays some commonly used system-related commands −
| Command | Purpose |
|---|---|
| cd | Changes current directory. |
| date | Displays current date. |
| delete | Deletes a file. |
| diary | Switches on/off diary file recording. |
| dir | Lists all files in current directory. |
| load | Loads workspace variables from a file. |
| path | Displays search path. |
| pwd | Displays current directory. |
| save | Saves workspace variables in a file. |
| type | Displays contents of a file. |
| what | Lists all MATLAB files in the current directory. |
| wklread | Reads .wk1 spreadsheet file. |
Input and Output Commands
MATLAB provides the following input and output related commands −
| Command | Purpose |
|---|---|
| disp | Displays contents of an array or string. |
| fscanf | Read formatted data from a file. |
| format | Controls screen-display format. |
| fprintf | Performs formatted writes to screen or file. |
| input | Displays prompts and waits for input. |
| ; | Suppresses screen printing. |
The fscanf and fprintf commands behave like C scanf and printf functions. They support the following format codes −
| Format Code | Purpose |
|---|---|
| %s | Format as a string. |
| %d | Format as an integer. |
| %f | Format as a floating point value. |
| %e | Format as a floating point value in scientific notation. |
| %g | Format in the most compact form: %f or %e. |
| n | Insert a new line in the output string. |
| t | Insert a tab in the output string. |
The format function has the following forms used for numeric display −
| Format Function | Display up to |
|---|---|
| format short | Four decimal digits (default). |
| format long | 16 decimal digits. |
| format short e | Five digits plus exponent. |
| format long e | 16 digits plus exponents. |
| format bank | Two decimal digits. |
| format + | Positive, negative, or zero. |
| format rat | Rational approximation. |
| format compact | Suppresses some line feeds. |
| format loose | Resets to less compact display mode. |
Vector, Matrix and Array Commands
The following table shows various commands used for working with arrays, matrices and vectors −
| Command | Purpose |
|---|---|
| cat | Concatenates arrays. |
| find | Finds indices of nonzero elements. |
| length | Computes number of elements. |
| linspace | Creates regularly spaced vector. |
| logspace | Creates logarithmically spaced vector. |
| max | Returns largest element. |
| min | Returns smallest element. |
| prod | Product of each column. |
| reshape | Changes size. |
| size | Computes array size. |
| sort | Sorts each column. |
| sum | Sums each column. |
| eye | Creates an identity matrix. |
| ones | Creates an array of ones. |
| zeros | Creates an array of zeros. |
| cross | Computes matrix cross products. |
| dot | Computes matrix dot products. |
| det | Computes determinant of an array. |
| inv | Computes inverse of a matrix. |
| pinv | Computes pseudoinverse of a matrix. |
| rank | Computes rank of a matrix. |
| rref | Computes reduced row echelon form. |
| cell | Creates cell array. |
| celldisp | Displays cell array. |
| cellplot | Displays graphical representation of cell array. |
| num2cell | Converts numeric array to cell array. |
| deal | Matches input and output lists. |
| iscell | Identifies cell array. |
Plotting Commands
MATLAB provides numerous commands for plotting graphs. The following table shows some of the commonly used commands for plotting −
| Command | Purpose |
|---|---|
| axis | Sets axis limits. |
| fplot | Intelligent plotting of functions. |
| grid | Displays gridlines. |
| plot | Generates xy plot. |
| Prints plot or saves plot to a file. | |
| title | Puts text at top of plot. |
| xlabel | Adds text label to x-axis. |
| ylabel | Adds text label to y-axis. |
| axes | Creates axes objects. |
| close | Closes the current plot. |
| close all | Closes all plots. |
| figure | Opens a new figure window. |
| gtext | Enables label placement by mouse. |
| hold | Freezes current plot. |
| legend | Legend placement by mouse. |
| refresh | Redraws current figure window. |
| set | Specifies properties of objects such as axes. |
| subplot | Creates plots in subwindows. |
| text | Places string in figure. |
| bar | Creates bar chart. |
| loglog | Creates log-log plot. |
| polar | Creates polar plot. |
| semilogx | Creates semilog plot. (logarithmic abscissa). |
| semilogy | Creates semilog plot. (logarithmic ordinate). |
| stairs | Creates stairs plot. |
| stem | Creates stem plot. |
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