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Diffstat (limited to 'matlab.html.markdown')
| -rw-r--r-- | matlab.html.markdown | 44 |
1 files changed, 39 insertions, 5 deletions
diff --git a/matlab.html.markdown b/matlab.html.markdown index 4d97834c..51b7bd4e 100644 --- a/matlab.html.markdown +++ b/matlab.html.markdown @@ -15,6 +15,7 @@ If you have any feedback please feel free to reach me at [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. %{ @@ -24,6 +25,23 @@ like this %} +% Two percent signs denote the start of a new code section +% Individual code sections can be run by moving the cursor to the section followed by +% either clicking the "Run Section" button +% or using Ctrl+Shift+Enter (Windows) or Cmd+Shift+Return (OS X) + +%% This is the start of a code section +% One way of using sections is to separate expensive but unchanging start-up code like loading data +load myFile.mat y + +%% This is another code section +% This section can be edited and run repeatedly on its own, and is helpful for exploratory programming and demos +A = A * 2; +plot(A); + +%% Code sections are also known as code cells or cell mode (not to be confused with cell arrays) + + % commands can span multiple lines, using '...': a = 1 + 2 + ... + 4 @@ -72,7 +90,7 @@ c = exp(a)*sin(pi/2) % c = 7.3891 % Calling functions can be done in either of two ways: % Standard function syntax: -load('myFile.mat', 'y') % arguments within parantheses, spererated by commas +load('myFile.mat', 'y') % arguments within parentheses, separated by commas % Command syntax: 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 @@ -123,6 +141,7 @@ x(2:end) % ans = 32 53 7 1 x = [4; 32; 53; 7; 1] % Column vector x = [1:10] % x = 1 2 3 4 5 6 7 8 9 10 +x = [1:2:10] % Increment by 2, i.e. x = 1 3 5 7 9 % Matrices A = [1 2 3; 4 5 6; 7 8 9] @@ -205,6 +224,8 @@ transpose(A) % Transpose the matrix, which is the same as: A one ctranspose(A) % Hermitian transpose the matrix % (the transpose, followed by taking complex conjugate of each element) +A' % Concise version of complex transpose +A.' % Concise version of transpose (without taking complex conjugate) @@ -254,6 +275,8 @@ axis equal % Set aspect ratio so data units are the same in every direction scatter(x, y); % Scatter-plot hist(x); % Histogram +stem(x); % Plot values as stems, useful for displaying discrete data +bar(x); % Plot bar graph z = sin(x); plot3(x,y,z); % 3D line plot @@ -262,7 +285,7 @@ pcolor(A) % Heat-map of matrix: plot as grid of rectangles, coloured by value contour(A) % Contour plot of matrix mesh(A) % Plot as a mesh surface -h = figure % Create new figure object, with handle h +h = figure % Create new figure object, with handle h figure(h) % Makes the figure corresponding to handle h the current figure close(h) % close figure with handle h close all % close all open figure windows @@ -273,7 +296,7 @@ clf clear % clear current figure window, and reset most figure properties % Properties can be set and changed through a figure handle. % You can save a handle to a figure when you create it. -% The function gcf returns a handle to the current figure +% The function get returns a handle to the current figure h = plot(x, y); % you can save a handle to a figure when you create it set(h, 'Color', 'r') % 'y' yellow; 'm' magenta, 'c' cyan, 'r' red, 'g' green, 'b' blue, 'w' white, 'k' black @@ -400,7 +423,7 @@ exp(x) sqrt(x) log(x) log10(x) -abs(x) +abs(x) %If x is complex, returns magnitude min(x) max(x) ceil(x) @@ -411,6 +434,14 @@ rand % Uniformly distributed pseudorandom numbers randi % Uniformly distributed pseudorandom integers randn % Normally distributed pseudorandom numbers +%Complex math operations +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 + + % Common constants pi NaN @@ -460,11 +491,14 @@ length % length of a vector sort % sort in ascending order sum % sum of elements prod % product of elements -mode % modal value +mode % modal value 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, + % 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 |