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In the Matlab editor, Matlab parses%% delimited blocks as 'sections' which you can run as a unit independent of running the whole script. MATLAB Commands – 11 M-Files eval Interpret strings containing Matlab expressions. Feval Function evaluation. Function Creates a user-defined function M-file. Global Define global variables. Nargin Number of function input arguments. Nargout Number of function output arguments. Script Script M-files Timing cputime CPU time in seconds. If you assign row names with leading or trailing whitespace characters, then MATLAB ® removes them from the row names. The row names are visible when you view the table. Furthermore, you can use the row names within parentheses or curly braces to access the table data. Matlab is a newest and simple online tool for the trainees to resolve their prolonged or common quarries on various computing or mathematical topics. Topics like Electronics, Electrical, Civil, Mechanical Engineering and so on. Matlab Assignment Help is a numerical computing programming language.

Keeping this slow down due to the interpretive nature of Matlab in mind, one programming construct that should be avoided at all costs is the for loop, especially nested for loops since these can make a Matlab programs run time orders of magnitude longer than may be needed. Often for loops can be eliminated using Matlab’s vectorized addressing.

MATLAB environment behaves like a super-complex calculator. You can enter commands at the >> command prompt.

MATLAB is an interpreted environment. In other words, you give a command and MATLAB executes it right away.

Type a valid expression, for example,

And press ENTER

When you click the Execute button, or type Ctrl+E, MATLAB executes it immediately and the result returned is −

Let us take up few more examples −

When you click the Execute button, or type Ctrl+E, MATLAB executes it immediately and the result returned is −

Another example,

When you click the Execute button, or type Ctrl+E, MATLAB executes it immediately and the result returned is −

Another example,

Another example,

MATLAB provides some special expressions for some mathematical symbols, like pi for π, Inf for ∞, i (and j) for √-1 etc. **Nan** stands for 'not a number'.

Semicolon (;) indicates end of statement. However, if you want to suppress and hide the MATLAB output for an expression, add a semicolon after the expression.

For example,

The percent symbol (%) is used for indicating a comment line. For example,

You can also write a block of comments using the block comment operators % { and % }.

The MATLAB editor includes tools and context menu items to help you add, remove, or change the format of comments.

MATLAB supports the following commonly used operators and special characters −

Operator | Purpose |
---|---|

+ | Plus; addition operator. |

- | Minus; subtraction operator. |

* | Scalar and matrix multiplication operator. |

.* | Array multiplication operator. |

^ | Scalar and matrix exponentiation operator. |

.^ | Array exponentiation operator. |

Left-division operator. | |

/ | Right-division operator. |

. | Array left-division operator. |

./ | Array right-division operator. |

: | Colon; generates regularly spaced elements and represents an entire row or column. |

( ) | Parentheses; encloses function arguments and array indices; overrides precedence. |

[ ] | Brackets; enclosures array elements. |

. | Decimal point. |

… | Ellipsis; line-continuation operator |

, | Comma; separates statements and elements in a row |

; | Semicolon; separates columns and suppresses display. |

% | Percent sign; designates a comment and specifies formatting. |

_ | Quote sign and transpose operator. |

._ | Nonconjugated transpose operator. |

= | Assignment operator. |

MATLAB supports the following special variables and constants −

Name | Meaning |
---|---|

ans | Most recent answer. |

eps | Accuracy of floating-point precision. |

i,j | The imaginary unit √-1. |

Inf | Infinity. |

NaN | Undefined numerical result (not a number). |

pi | The number π |

Variable names consist of a letter followed by any number of letters, digits or underscore.

MATLAB is **case-sensitive**.

Variable names can be of any length, however, MATLAB uses only first N characters, where N is given by the function **namelengthmax**.

The **save** command is used for saving all the variables in the workspace, as a file with .mat extension, in the current directory.

For example,

You can reload the file anytime later using the **load** command.

L. Oberbroeckling, Spring 2018.

This document gives BASIC ways to color graphs in MATLAB. See

and

for more in-depth explanations and fancier coloring, to name just two sources.

The default colors used in MATLAB changed in R2014b version. Here are the colors, in order, and their MATLAB RGB triplet.

Current color | Old color | ||
---|---|---|---|

[0, 0.4470, 0.7410] | [0, 0, 1] | ||

[0.8500, 0.3250, 0.0980] | [0, 0.5, 0] | ||

[0.9290, 0.6940, 0.1250] | [1, 0, 0] | ||

[0.4940, 0.1840, 0.5560] | [0, 0.75, 0.75] | ||

[0.4660, 0.6740, 0.1880] | [0.75, 0, 0.75] | ||

[0.3010, 0.7450, 0.9330] | [0.75, 0.75, 0] | ||

[0.6350, 0.0780, 0.1840] | [0.25, 0.25, 0.25] |

Another thing that changed starting in the R2014b version is that the `hold on` and `hold off` automatically cycles through the colors. In the past, each new `plot` command would start with the first color (blue) and you would have to manually change the color. Now it will automatically move to the next color(s). See below for how to manually adjust the colors.

If using `mesh(x,y,z)`, to change the look of it you would want to change `'EdgeColor'`. Note that the name of this colormap is 'parula' while previous to R2014b, it was 'jet'

The eight basic colors are known by either their short name or long name (RGB triplets are also included).

Long Name | Short Name | RGB Triplet |
---|---|---|

blue | b | [0,0,1] |

black | k | [0,0,0] |

red | r | [1,0,0] |

green | g | [0,1,0] |

yellow | y | [1,1,0] |

cyan | c | [0,1,1] |

magenta | m | [1,0,1] |

white | w | [1,1,1] |

Example of how to change the color using short names is below. You can easily do the same thing using the long names.

Many times you want to have more control of what colors are used. For example, I may want some data points drawn in the same color as the curve. Or I have a piece-wise graph that I want to have all the same color. There are several ways to do this. One is to use the default colors and 'resetting' the order, which is shown here. Others involve using the RGB triplet (see next section).

As you may see, this could get confusing to keep track of. Thus it may be easier to use the RGB triplets, and even name them ahead of time. This is discussed in the section below.

One can specify colors using a vector that gives the RGB triple where in MATLAB, each of the three values are numbers from 0 to 1. Usually RGB colors have values from 0 to 255. You can use those numbers and divide the vector by 255 to use within MATLAB. Thus knowing the MATLAB RGB triples for the colors can be useful. From the table above, we can define the default colors to work with them or can put in the RGB triplet (as a vector) directly into the `plot` command. Both are shown in this example.

For other colors, you can look up their RGB code on many websites such as RGB Color Codes Chart or HTML Color Picker to see the RGB codes (or hex codes, etc.) For example, at these RGB Color websites, you will be given R=255, G=0, B=0 for red. So you can use 1/255[255,0,0] to get the color of red to use as a color in MATLAB.

The official color for Loyola Green is given as RGB:0-104-87, and Loyola Gray is given as RGB:200-200-200 (found on Loyola's Logos/University Signature page. Here's how one can use those colors in MATLAB.

Now one can use these colors to specify the color of markers, lines, edges, faces, etc.

If using `mesh(x,y,z)`, to change the look of it you can change to a different `colormap` as discussed in https://www.mathworks.com/help/matlab/ref/colormap.html. This was done above when showing the previous default colormap. Here are some more.

**Warning!** Once you change the colormap, it will keep that colormap for all subsequent 3D plots within the same figure or MATLAB session until you use `close`, or open a new `figure` window.

For `mesh` and `surf`, you can change `'EdgeColor'` and/or `'FaceColor'` to be uniform, rather than using colormaps.

Published with MATLAB® R2016a

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