Merge variable episodes

config.yaml

@@ -58,22 +58,21 @@ contact: '[email protected]'
 # - another-learner.md
 
 # Order of episodes in your lesson
-episodes: 
+episodes:
 - introduction.md
 - what-is-matlab.md
 - matlab-layout.md
 - variables-and-dimensions.md
-- creating-variables.md
 - manipulating-variables.md
 
 # Information for Learners
-learners: 
+learners:
 
 # Information for Instructors
-instructors: 
+instructors:
 
 # Learner Profiles
-profiles: 
+profiles:
 
 # Customisation ---------------------------------------------
 #

episodes/variables-and-dimensions.md

@@ -40,6 +40,7 @@ The value of a variable in MATLAB can be many things! Some examples are
 |Matrix| [1 2 3; 4 5 6]|
 |Logical| True, False|
 
+## TODO: variable naming convention
 
 As mentioned in the previous episode, MATLAB has a section called the workspace, this is where you can view what Variables are in-memory. The most simple way of creating a variable is with the '=' symbol, for example:
 ```
@@ -91,7 +92,7 @@ Use the `penny` command in the command window. this command will create an inter
 
 ::: hint
 
-If you double click a variable name in the workspace you can explore it in a spreadsheet style interface
+If you double click a variable name in the workspace you can explore it in a spreadsheet style interface, this is called the variable editor.
 
 :::
 
@@ -130,6 +131,7 @@ In general when creating multidimensional variables you
 - separate columns with a space ` `
 - separate rows with a semi-colon `;`
 
+## TODO: make this read nicer, all in challenge?
 ::: challenge
 
 1. Create a 1x3 row vector named E: `E = [1 2 3]`
@@ -156,12 +158,120 @@ Simply putting `clear` into your command window will clear all variables
 `clear A` will clear just the variable called A
 
 **Clear command window**
-
+## TODO clearup history
 After working a while you will have a long history of commands in your command window, you can clear this up by typing `clc` (command line clear).
 
 ::: callout
 You can access commands you have previously typed in the command window by pressing the up arrow on your keyboard
 :::
+
+
+## Indexing
+
+### Colon Notation
+
+MATLAB provides what is called the colon notation which allows us to specify a range of values.
+
+``` MATLAB
+a = [1:10]
+```
+``` OUTPUT
+a =
+
+     1     2     3     4     5     6     7     8     9    10
+```
+
+`a` should be 1x10 size, meaning 1 row 10 columns
+
+### Steps
+You can also specify a step, so the colon notation only makes every nth number 
+
+``` MATLAB
+
+b = [1:2:20]
+
+```
+
+``` OUTPUT
+
+b =
+
+     1     3     5     7     9    11    13    15    17    19
+```
+
+## Functions
+
+We can also use functions to create arrays. Functions are premade code blocks that serve a commonly wanted functionality.
+
+First we will use one called linspace, which stands for linearly spaced. It creates a vector of linearly spaced numbers, you specify the start, end and how many numbers.
+
+::: callout
+
+If you are ever unsure about a function MATLAB has inbuilt help and documentation!
+
+The help command will give a brief text description about the function and how to use it
+``` MATLAB
+help linspace
+```
+
+The doc command will give a more detailed description including examples
+``` MATLAB
+doc linspace
+```
+
+:::
+
+``` MATLAB
+
+c = linspace(1,10,5)
+
+```
+
+``` OUTPUT
+
+c =
+
+    1.0000    3.2500    5.5000    7.7500   10.0000
+    
+```
+
+Some other useful functions are:
+``` MATLAB
+% Rand creates an n-dimensional array of random numberes between 0 and 1.
+d = rand(5,1)
+
+% Create matrix of 0's
+e = zeros(2,2)
+
+% NaN means 'Not a Number', this is a special and useful term for when a value can't be represented by a number. 
+f = nan(5,5)
+```
+::: callout
+
+Here are some common scenarios where NaN may be used:
+
+- Mathematical operations that cant be computed (division by 0, root of negative numbers)
+- No data was recorded, for example a in-field sensor may have lost power
+
+:::
+
+::: challenge
+
+1. Create a vector with numbers 12 to 100 containing every 4th number (steps of 4), call it g
+2. Create a matrix of random numbers with 4 rows and 5 columns, call it h
+
+::: solution
+``` MATLAB
+g = 12:4:100
+or
+g = linspace(12,100,23)
+```
+:::
+
+:::
+
+
+
 ::::::::::::::::::::::::::::::::::::: keypoints 
 
 - Variables are the main way we access and use data in MATLAB