```matlab
% QCB W12: Intro to MatLab Fall 2024
% Day 1
% ---------------------------------

% comments
```
# Section breaks
```matlab
a=1;
display(a)
```

```matlab
b=2;
display(b)
```

```matlab
display(a+b)
```
# Variables
```matlab
% assignment command: put a value on the right side of '=' into
% a 'pigeon hole' named on the left
%a = 2
%b = 4;
%c = a + b;    % this is *not* an equation !!!
```
# Values & math functions
```matlab
%a = 1;     % note: numbers are, in general, complex - i = sqrt(-1)
%b = 1e-3;  % scientific notation
% common math operations/functions
%c = 1 + 2*3 + 2 * 3^2;  % Note: some other languages use ** in place of ^
%d = sin(0) + cos(pi);   % trig functions
%e = exp(-10/100); % same as exp(1)^(-10/100)
%f = log(1) +log2(2) + log10(10);  % different bases
%g = sqrt(-2);  % Note: this is valid - complex numbers are OK !!!

%s = 'this is a string';
```
# Every variable (and every value) can be a matrix (aka array)
```matlab
% create by hand
%---------------

%A = [1,2,3,4,5,6]; % 1 row, 5 columns; check with size(A)
%B = [1;2;3;4;5;6]; % 5 rows, 1 column
%C = [1,2,3;4,5,6]; % 2 rows, 3 columns (commas are optional)
%A10 = 10 * A

% concatanation
%--------------

%D = cat( 1, A, A );   % example of a function: like math
%       - takes argument(s)
%       - may return value(s)

%E = circshift(A,1);   %  another function...

% access element(s)
%-----------------

% A(1) + B(5,1) + C(2,3)  % note: idices start with 1 (NOT zero  !!!)
% A(2:4)   % 'slice'  ; note: 4th element *is* included
% A(3:end)
% A(3:end-2)

% matrix 'discovery' functions
%-----------------------------

numel(A)   % number of elements
size(A)    % dimensions
length(A)  % largest dimension

% matrix construction tools
%--------------------------

% useful functions
%-----------------

%Z = zeros(4,6);
%O = ones(6,4);
%I = eye(4);  % note: square matrix !!!

% ranges
%-------

%R10 = 1:10;  % Note: 10 elements (defult step - 1)
%R20 = 1:0.5:10;  % Explicit step (0.5)

% random numbers
%---------------

% reshuffled range (random parmutationrange)
%Ar = randomperm(10)

% uniform distribution over (0,1) range
%U42 = rand(4,2); % 4 x 2 array of random numbers
%U44 = rand(4);  % same as above but square matrix

%normal distribution
%N42 = randn(4,2) % 4 x 2 array of rande
%N44 = randn(4) % same as above, square matrix
```
# saving/loading workspace
```matlab
%save myworkspace.mat
%load myworkspace.mat
```
# for loops
```matlab
%for ii = 1:10
%    fprintf("%5i   %6i    %.3f   %.3f\n", ii, ii^2, sqrt(ii), ii^2+3*randn(1) );
%end
```
# saving data
```matlab
myOutFile = "mydata_1.tab";
%
%fout = fopen(myOutFile, 'w');

%for ii = 1:10
%    fprintf(fout, "%5i %6i %.3f %.3f %.3f\n", ii, ii^2, ii+2*randn(1), ii^2+3*randn(1) );
%end
%fclose(fout);
```
# reading data

mydata=importdata(myOutFile);

```matlab
% mydata=importtable(myOutFile);
```