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removing whitespace all over
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@@ -6,7 +6,7 @@ contributors:
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---
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MATLAB stands for MATrix LABoratory. It is a powerful numerical computing language commonly used in engineering and mathematics.
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MATLAB stands for MATrix LABoratory. It is a powerful numerical computing language commonly used in engineering and mathematics.
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If you have any feedback please feel free to reach me at
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[@the_ozzinator](https://twitter.com/the_ozzinator), or
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@@ -16,7 +16,7 @@ If you have any feedback please feel free to reach me at
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% Comments start with a percent sign.
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%{
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Multi line comments look
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Multi line comments look
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something
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like
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this
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@@ -62,10 +62,10 @@ disp('text') % print "text" to the screen
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% Variables & Expressions
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myVariable = 4 % Notice Workspace pane shows newly created variable
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myVariable = 4; % Semi colon suppresses output to the Command Window
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4 + 6 % ans = 10
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8 * myVariable % ans = 32
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2 ^ 3 % ans = 8
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a = 2; b = 3;
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4 + 6 % ans = 10
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8 * myVariable % ans = 32
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2 ^ 3 % ans = 8
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a = 2; b = 3;
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c = exp(a)*sin(pi/2) % c = 7.3891
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% Calling functions can be done in either of two ways:
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@@ -73,7 +73,7 @@ c = exp(a)*sin(pi/2) % c = 7.3891
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load('myFile.mat', 'y') % arguments within parantheses, spererated by commas
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% Command syntax:
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load myFile.mat y % no parentheses, and spaces instead of commas
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% Note the lack of quote marks in command form: inputs are always passed as
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% Note the lack of quote marks in command form: inputs are always passed as
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% literal text - cannot pass variable values. Also, can't receive output:
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[V,D] = eig(A); % this has no equivalent in command form
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[~,D] = eig(A); % if you only want D and not V
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@@ -103,7 +103,7 @@ a(2) % ans = y
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% Cells
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a = {'one', 'two', 'three'}
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a = {'one', 'two', 'three'}
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a(1) % ans = 'one' - returns a cell
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char(a(1)) % ans = one - returns a string
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@@ -113,7 +113,7 @@ A.c = [1 2];
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A.d.e = false;
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% Vectors
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x = [4 32 53 7 1]
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x = [4 32 53 7 1]
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x(2) % ans = 32, indices in Matlab start 1, not 0
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x(2:3) % ans = 32 53
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x(2:end) % ans = 32 53 7 1
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@@ -123,7 +123,7 @@ x = [4; 32; 53; 7; 1] % Column vector
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x = [1:10] % x = 1 2 3 4 5 6 7 8 9 10
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% Matrices
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A = [1 2 3; 4 5 6; 7 8 9]
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A = [1 2 3; 4 5 6; 7 8 9]
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% Rows are separated by a semicolon; elements are separated with space or comma
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% A =
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@@ -132,7 +132,7 @@ A = [1 2 3; 4 5 6; 7 8 9]
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% 7 8 9
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A(2,3) % ans = 6, A(row, column)
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A(6) % ans = 8
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A(6) % ans = 8
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% (implicitly concatenates columns into vector, then indexes into that)
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@@ -171,7 +171,7 @@ A(1,:) % All columns in row 1
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% 4 5 42
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% 7 8 9
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% this is the same as
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% this is the same as
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vertcat(A,A);
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@@ -183,7 +183,7 @@ vertcat(A,A);
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% 4 5 42 4 5 42
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% 7 8 9 7 8 9
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% this is the same as
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% this is the same as
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horzcat(A,A);
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@@ -201,21 +201,21 @@ A(:, 1) =[] % Delete the first column of the matrix
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transpose(A) % Transpose the matrix, which is the same as:
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A one
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ctranspose(A) % Hermitian transpose the matrix
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ctranspose(A) % Hermitian transpose the matrix
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% (the transpose, followed by taking complex conjugate of each element)
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% Element by Element Arithmetic vs. Matrix Arithmetic
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% Element by Element Arithmetic vs. Matrix Arithmetic
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% On their own, the arithmetic operators act on whole matrices. When preceded
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% by a period, they act on each element instead. For example:
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A * B % Matrix multiplication
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A .* B % Multiple each element in A by its corresponding element in B
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% There are several pairs of functions, where one acts on each element, and
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% There are several pairs of functions, where one acts on each element, and
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% the other (whose name ends in m) acts on the whole matrix.
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exp(A) % exponentiate each element
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exp(A) % exponentiate each element
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expm(A) % calculate the matrix exponential
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sqrt(A) % take the square root of each element
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sqrtm(A) % find the matrix whose square is A
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@@ -233,7 +233,7 @@ axis([0 2*pi -1 1]) % x range from 0 to 2*pi, y range from -1 to 1
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plot(x,y1,'-',x,y2,'--',x,y3,':') % For multiple functions on one plot
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legend('Line 1 label', 'Line 2 label') % Label curves with a legend
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% Alternative method to plot multiple functions in one plot.
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% Alternative method to plot multiple functions in one plot.
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% while 'hold' is on, commands add to existing graph rather than replacing it
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plot(x, y)
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hold on
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@@ -271,9 +271,9 @@ clf clear % clear current figure window, and reset most figure properties
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% Properties can be set and changed through a figure handle.
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% You can save a handle to a figure when you create it.
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% The function gcf returns a handle to the current figure
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% The function gcf returns a handle to the current figure
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h = plot(x, y); % you can save a handle to a figure when you create it
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set(h, 'Color', 'r')
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set(h, 'Color', 'r')
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% 'y' yellow; 'm' magenta, 'c' cyan, 'r' red, 'g' green, 'b' blue, 'w' white, 'k' black
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set(h, 'LineStyle', '--')
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% '--' is solid line, '---' dashed, ':' dotted, '-.' dash-dot, 'none' is no line
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@@ -298,8 +298,8 @@ cd /path/to/move/into % change directory
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% Variables can be saved to .mat files
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save('myFileName.mat') % Save the variables in your Workspace
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load('myFileName.mat') % Load saved variables into Workspace
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save('myFileName.mat') % Save the variables in your Workspace
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load('myFileName.mat') % Load saved variables into Workspace
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% M-file Scripts
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% A script file is an external file that contains a sequence of statements.
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@@ -312,11 +312,11 @@ load('myFileName.mat') % Load saved variables into Workspace
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% Also, they have their own workspace (ie. different variable scope).
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% Function name should match file name (so save this example as double_input.m).
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% 'help double_input.m' returns the comments under line beginning function
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function output = double_input(x)
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function output = double_input(x)
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%double_input(x) returns twice the value of x
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output = 2*x;
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end
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double_input(6) % ans = 12
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double_input(6) % ans = 12
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% You can also have subfunctions and nested functions.
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@@ -325,8 +325,8 @@ double_input(6) % ans = 12
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% functions, and have access to both its workspace and their own workspace.
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% If you want to create a function without creating a new file you can use an
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% anonymous function. Useful when quickly defining a function to pass to
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% another function (eg. plot with fplot, evaluate an indefinite integral
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% anonymous function. Useful when quickly defining a function to pass to
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% another function (eg. plot with fplot, evaluate an indefinite integral
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% with quad, find roots with fzero, or find minimum with fminsearch).
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% Example that returns the square of it's input, assigned to to the handle sqr:
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sqr = @(x) x.^2;
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@@ -336,12 +336,12 @@ doc function_handle % find out more
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% User input
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a = input('Enter the value: ')
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% Stops execution of file and gives control to the keyboard: user can examine
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% Stops execution of file and gives control to the keyboard: user can examine
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% or change variables. Type 'return' to continue execution, or 'dbquit' to exit
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keyboard
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% Reading in data (also xlsread/importdata/imread for excel/CSV/image files)
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fopen(filename)
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fopen(filename)
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% Output
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disp(a) % Print out the value of variable a
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@@ -363,8 +363,8 @@ end
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for k = 1:5
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disp(k)
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end
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k = 0;
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k = 0;
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while (k < 5)
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k = k + 1;
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end
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@@ -382,7 +382,7 @@ password = 'root';
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driver = 'com.mysql.jdbc.Driver';
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dburl = ['jdbc:mysql://localhost:8889/' dbname];
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javaclasspath('mysql-connector-java-5.1.xx-bin.jar'); %xx depends on version, download available at http://dev.mysql.com/downloads/connector/j/
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conn = database(dbname, username, password, driver, dburl);
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conn = database(dbname, username, password, driver, dburl);
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sql = ['SELECT * from table_name where id = 22'] % Example sql statement
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a = fetch(conn, sql) %a will contain your data
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@@ -394,7 +394,7 @@ tan(x)
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asin(x)
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acos(x)
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atan(x)
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exp(x)
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exp(x)
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sqrt(x)
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log(x)
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log10(x)
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@@ -426,7 +426,7 @@ pinv(A) % calculate the pseudo-inverse
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zeros(m,n) % m x n matrix of 0's
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ones(m,n) % m x n matrix of 1's
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diag(A) % Extracts the diagonal elements of a matrix A
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diag(x) % Construct a matrix with diagonal elements listed in x, and zeroes elsewhere
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diag(x) % Construct a matrix with diagonal elements listed in x, and zeroes elsewhere
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eye(m,n) % Identity matrix
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linspace(x1, x2, n) % Return n equally spaced points, with min x1 and max x2
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inv(A) % Inverse of matrix A
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@@ -452,15 +452,15 @@ flipud(A) % Flip matrix up to down
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[U,S,V] = svd(X) % SVD: XV = US, U and V are unitary matrices, S has non-negative diagonal elements in decreasing order
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% Common vector functions
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max % largest component
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min % smallest component
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max % largest component
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min % smallest component
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length % length of a vector
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sort % sort in ascending order
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sum % sum of elements
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sort % sort in ascending order
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sum % sum of elements
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prod % product of elements
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mode % modal value
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median % median value
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mean % mean value
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median % median value
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mean % mean value
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std % standard deviation
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perms(x) % list all permutations of elements of x
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