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Diffstat (limited to 'matlab.html.markdown')
| -rw-r--r-- | matlab.html.markdown | 85 |
1 files changed, 40 insertions, 45 deletions
diff --git a/matlab.html.markdown b/matlab.html.markdown index 07f73cfb..ddf79f05 100644 --- a/matlab.html.markdown +++ b/matlab.html.markdown @@ -10,10 +10,6 @@ contributors: MATLAB stands for MATrix LABoratory. It is a powerful numerical computing language commonly used in engineering and mathematics. -If you have any feedback please feel free to reach me at -[@the_ozzinator](https://twitter.com/the_ozzinator), or -[osvaldo.t.mendoza@gmail.com](mailto:osvaldo.t.mendoza@gmail.com). - ```matlab %% Code sections start with two percent signs. Section titles go on the same line. % Comments start with a percent sign. @@ -49,42 +45,42 @@ plot(A); % commands can be passed to the operating system !ping google.com -who % Displays all variables in memory -whos % Displays all variables in memory, with their types -clear % Erases all your variables from memory -clear('A') % Erases a particular variable +who % Displays all variables in memory +whos % Displays all variables in memory, with their types +clear % Erases all your variables from memory +clear('A') % Erases a particular variable openvar('A') % Open variable in variable editor -clc % Erases the writing on your Command Window -diary % Toggle writing Command Window text to file +clc % Erases the writing on your Command Window +diary % Toggle writing Command Window text to file ctrl-c % Abort current computation edit('myfunction.m') % Open function/script in editor type('myfunction.m') % Print the source of function/script to Command Window -profile on % turns on the code profiler -profile off % turns off the code profiler -profile viewer % Open profiler +profile on % turns on the code profiler +profile off % turns off the code profiler +profile viewer % Open profiler -help command % Displays documentation for command in Command Window -doc command % Displays documentation for command in Help Window -lookfor command % Searches for command in the first commented line of all functions +help command % Displays documentation for command in Command Window +doc command % Displays documentation for command in Help Window +lookfor command % Searches for command in the first commented line of all functions lookfor command -all % searches for command in all functions % Output formatting -format short % 4 decimals in a floating number -format long % 15 decimals -format bank % only two digits after decimal point - for financial calculations +format short % 4 decimals in a floating number +format long % 15 decimals +format bank % only two digits after decimal point - for financial calculations fprintf('text') % print "text" to the screen -disp('text') % print "text" to the screen +disp('text') % print "text" to the screen % Variables & Expressions -myVariable = 4 % Notice Workspace pane shows newly created variable +myVariable = 4 % Notice Workspace pane shows newly created variable myVariable = 4; % Semi colon suppresses output to the Command Window -4 + 6 % ans = 10 -8 * myVariable % ans = 32 -2 ^ 3 % ans = 8 +4 + 6 % ans = 10 +8 * myVariable % ans = 32 +2 ^ 3 % ans = 8 a = 2; b = 3; c = exp(a)*sin(pi/2) % c = 7.3891 @@ -92,7 +88,7 @@ c = exp(a)*sin(pi/2) % c = 7.3891 % Standard function syntax: load('myFile.mat', 'y') % arguments within parentheses, separated by commas % Command syntax: -load myFile.mat y % no parentheses, and spaces instead of commas +load myFile.mat y % no parentheses, and spaces instead of commas % Note the lack of quote marks in command form: inputs are always passed as % literal text - cannot pass variable values. Also, can't receive output: [V,D] = eig(A); % this has no equivalent in command form @@ -338,8 +334,8 @@ load('myFileName.mat') % Load saved variables into Workspace % Function name should match file name (so save this example as double_input.m). % 'help double_input.m' returns the comments under line beginning function function output = double_input(x) - %double_input(x) returns twice the value of x - output = 2*x; + %double_input(x) returns twice the value of x + output = 2*x; end double_input(6) % ans = 12 @@ -375,23 +371,23 @@ fprintf % Print to Command Window with more control % Conditional statements (the parentheses are optional, but good style) if (a > 23) - disp('Greater than 23') + disp('Greater than 23') elseif (a == 23) - disp('a is 23') + disp('a is 23') else - disp('neither condition met') + disp('neither condition met') end % Looping % NB. looping over elements of a vector/matrix is slow! % Where possible, use functions that act on whole vector/matrix at once for k = 1:5 - disp(k) + disp(k) end k = 0; while (k < 5) - k = k + 1; + k = k + 1; end % Timing code execution: 'toc' prints the time since 'tic' was called @@ -435,11 +431,11 @@ randi % Uniformly distributed pseudorandom integers randn % Normally distributed pseudorandom numbers %Complex math operations -abs(x) % Magnitude of complex variable x +abs(x) % Magnitude of complex variable x phase(x) % Phase (or angle) of complex variable x real(x) % Returns the real part of x (i.e returns a if x = a +jb) imag(x) % Returns the imaginary part of x (i.e returns b if x = a+jb) -conj(x) % Returns the complex conjugate +conj(x) % Returns the complex conjugate % Common constants @@ -496,23 +492,23 @@ median % median value mean % mean value std % standard deviation perms(x) % list all permutations of elements of x -find(x) % Finds all non-zero elements of x and returns their indexes, can use comparison operators, +find(x) % Finds all non-zero elements of x and returns their indexes, can use comparison operators, % i.e. find( x == 3 ) returns indexes of elements that are equal to 3 % i.e. find( x >= 3 ) returns indexes of elements greater than or equal to 3 % Classes -% MATLAB can support object-oriented programming. -% Classes must be put in a file of the class name with a .m extension. +% MATLAB can support object-oriented programming. +% Classes must be put in a file of the class name with a .m extension. % To begin, we create a simple class to store GPS waypoints. % Begin WaypointClass.m classdef WaypointClass % The class name. properties % The properties of the class behave like Structures - latitude - longitude + latitude + longitude end - methods - % This method that has the same name of the class is the constructor. + methods + % This method that has the same name of the class is the constructor. function obj = WaypointClass(lat, lon) obj.latitude = lat; obj.longitude = lon; @@ -543,12 +539,12 @@ a.longitude = 25.0 % Methods can be called in the same way as functions ans = multiplyLatBy(a,3) -% The method can also be called using dot notation. In this case, the object +% The method can also be called using dot notation. In this case, the object % does not need to be passed to the method. ans = a.multiplyLatBy(1/3) -% MATLAB functions can be overloaded to handle objects. -% In the method above, we have overloaded how MATLAB handles +% MATLAB functions can be overloaded to handle objects. +% In the method above, we have overloaded how MATLAB handles % the addition of two Waypoint objects. b = WaypointClass(15.0, 32.0) c = a + b @@ -560,4 +556,3 @@ c = a + b * [The official MATLAB Answers forum](http://www.mathworks.com/matlabcentral/answers/) * [Loren on the Art of MATLAB](http://blogs.mathworks.com/loren/) * [Cleve's Corner](http://blogs.mathworks.com/cleve/) - |