Restructure Matlab cheatsheet

Signed-off-by: Aaron Erhardt <aaron.erhardt@t-online.de>

Matlab/Matlab.md

-# Matlab cheatsheet
+# Matrices
 
-## Matrices
+## Generate
 
-### Generate
-
-Manual
+### Manual
 
 ```matlab
 A = [1 2 3; 4 5 6]
@@ -14,41 +12,41 @@ A =
      4     5     6
 ```
 
-Zero
+### Zero
 
 ```matlab
 A = zeros(3)    % 3x3
 B = zeros(3, 2) % 3x2
 ```
 
-Ones
+### Ones
 
 ```matlab
 A = ones(3)    % 3x3
 B = ones(3, 2) % 3x2
 ```
 
-Eye (zeros with ones in the diagonal)
+### Eye (zeros with ones in the diagonal)
 
 ```matlab
 A = eye(3)    % 3x3
 B = eye(3, 2) % 3x2
 ```
 
-Magic
+### Magic
 
 ```matlab
 A = magic(3) % 3x3
 ```
 
-Random values (from 0 to 1)
+### Random values (from 0 to 1)
 
 ```matlab
 A = rand(3) .* 2 % 3x3 with values from 0 to 2
 B = rand(3, 2)   % 3x2
 ```
 
-Normally distributed random values (σ = 1, µ = 0)
+### Normally distributed random values (σ = 1, µ = 0)
 
 ```matlab
 A = randn(3) .* 2   % 3x3 with σ = 2, µ = 0
@@ -56,90 +54,82 @@ B = randn(3, 2)     % 3x2
 C = randn(3, 2) + 3 % 3x2 with σ = 1, µ = 3
 ```
 
-### Modify
+## Modify
 
-Transpose
+### Transpose
 
 ```matlab
 T = A'
 ```
 
-Invert
+### Invert
 
 ```matlab
 B = inv(A)
 ```
 
-Rotate
+### Rotate
 
 ```matlab
 B = rot90(A)
 ```
 
-Flip
+### Flip
 
 ```matlab
 B = flip(A)   % flip rows (top to bottom)
 B = fliplr(A) % flip columns (left to right)
 ```
 
-Multiply
+### Multiply
 
 ```matlab
 C = A * B
 ```
 
-Element wise multiplication
+### Element wise multiplication
 
 ```matlab
 C = A .* B
 ```
 
-### Access
+## Access
 
-As row vector
+### As row vector
 
 ```matlab
 A(:)
 ```
 
-Get rows
+### Get rows
 
 ```matlab
 A(1, :) % row 1
 ```
 
-Get columns
+### Get columns
 
 ```matlab
 A(:, 1) % column 1
 ```
 
-Get diagonal
+### Get diagonal
 
 ```matlab
 diag(A)       % main diagonal (top left to bottom right)
 diag(flip(A)) % other diagonal (bottom left to top right)
 ```
 
-### Linear equations
+## Linear equations
  
 ```matlab
 x = A \ b % solves Ax = b
 ```
 
-### Visualize
-
-Histogram
-
-```matlab
-histogram(A)
-histogram(A, 15) % place values in 15 groups
-```
 
-## Images
+# Images
 
-### Load image
+## Load image
 
 ```matlab
 img = imread('path_to_file')
@@ -158,132 +148,135 @@ colormap(gray()) % gray color map
 colormap(M)      % where M 255x3 with values from 0 to 1
 ```
 
-## Strings
 
-### Create
+# Datatypes
+
+## Struct
 
 ```matlab
-str = "Hello"
-fromChar = string(text)
+student.name = "TestStudent"                     % create
+student.age = 24                                 % add field
+student2 = struct('name', 'Student2', 'age', 23) % compact
+disp(student.name)                               % print name
 ```
 
-### Concatenate
 
-```matlab
-str2 = str + " World!"
-```
+## CellArray
 
-## Character array
+Array containing different data types
 
 ### Create
 
 ```matlab
-text = 'Hello'
-fromStr = char(str)
+ca = { 'chars', 9.81, 1 } % 1x3 cell array
 ```
 
-### Concatenate
+### Access elements
 
 ```matlab
-text2 = [text ' World!']
+ca(1) % -> 'chars'
 ```
 
-### Access characters
+### Get length
 
 ```matlab
-c = text(1) % first character
+length(ca)
 ```
 
-### Convert to number
+
+## Table
+
+### Properties
 
 ```matlab
-str2num('2')
+table.Properties
+table.Properties.VariableNames{1} % first column name
 ```
 
-## Output
-
-### Create formatted string
+### Access column by name
 
 ```matlab
-sprintf('value: %f', float_val)
+table.column_name % access column (as vector) with name "column_name"
 ```
 
-### Print string
+### Get sub-table
 
 ```matlab
-disp('Hello')
+table(:, 2) % second column as table
 ```
 
-### Print formatted string
+### Access values
 
 ```matlab
-% use \n for newline, the 1 is for printing to stdout
-fprintf(1, 'value: %d\n', 2)
+table{1, 2} % row 1, column 2, note brackets!
+table{:, 2} % column 2
 ```
 
 
-# Datatypes
+## Strings
 
-## Struct
+### Create
 
 ```matlab
-student.name = "TestStudent"                     % create
-student.age = 24                                 % add field
-student2 = struct('name', 'Student2', 'age', 23) % compact
-disp(student.name)                               % print name
+str = "Hello"
+fromChar = string(text)
 ```
 
-## CellArray
+### Concatenate
 
-Array containing different data types
+```matlab
+str2 = str + " World!"
+```
+
+
+## Character array
 
 ### Create
 
 ```matlab
-ca = { 'chars', 9.81, 1 } % 1x3 cell array
+text = 'Hello'
+fromStr = char(str)
 ```
 
-### Access elements
+### Concatenate
 
 ```matlab
-ca(1) % -> 'chars'
+text2 = [text ' World!']
 ```
 
-### Get length
+### Access characters
 
 ```matlab
-length(ca)
+c = text(1) % first character
 ```
 
-## Table
-
-### Properties
+### Convert to number
 
 ```matlab
-table.Properties
-table.Properties.VariableNames{1} % first column name
+str2num('2')
 ```
 
-### Access column by name
+## Output
+
+### Create formatted string
 
 ```matlab
-table.column_name % access column (as vector) with name "column_name"
+sprintf('value: %f', float_val)
 ```
 
-### Get sub-table
+### Print string
 
 ```matlab
-table(:, 2) % second column as table
+disp('Hello')
 ```
 
-### Access values
+### Print formatted string
 
 ```matlab
-table{1, 2} % row 1, column 2, note brackets!
-table{:, 2} % column 2
+% use \n for newline, the 1 is for printing to stdout
+fprintf(1, 'value: %d\n', 2)
 ```
 
-
 # Save and load
 
 ## Workspace
@@ -379,6 +372,13 @@ fplot(@sin, [-pi pi]); % from -pi to pi
 
 ## Charts
 
+### Histogram
+
+```matlab
+histogram(A)     % where A is a vector of values
+histogram(A, 15) % place values in 15 groups
+```
+
 ### Bar
 
 ```matlab
@@ -469,6 +469,7 @@ axis([XMIN XMAX YMIN YMAX]); % set scaling of both axes
 ```matlab
 fig = figure; % note: properties are case sensitive!
 fig = gcf;    % get handle to current figure
+clf;          % clear current figure
 ```
 
 ### Typical object hierarchy