Free-form inputs
To compute, press SHIFT + ENTER
In[1]:= 3 + 9 SHIFT + ENTER
Out[1]:= 12
To suppress output, add ; after the line
In[1]:= 3 + 9; SHIFT + ENTER -> no output
You can execute multiple lines at once
In[1]:= a = 2
b = a + 2
c = b ^ 3 SHIFT + ENTER
Out[1]:= 2
Out[2]:= 4
Out[3]:= 64
Starting from now, when we have output, it means that in the end of the previous line, we press SHIFT + ENTER.
To get the most recent output, use %
In[1]:= 3 + 9
Out[1]:= 12
In[1]:= % + 5
Out[1]:= 17
Basics in Programming
Variable
A variable starts with letters. If you want, you may add numbers into the variable name. It is much better if you start the variable name with lowercase
In[1]:= myVariable123 = 2
Out[1]:= 2
Please notice how I join the two words and the number into a single word. If you put space between the variable name, it will indicate multiplication
In[1]:= x = 3;
5 x x
Out[1]:= 45
To clear the variable, use Clear function
In[1]:= x = 2
Out[1]:= 2
In[2]:= 2 x
Out[2]:= 4
In[3]:= Clear[x]
In[4]:= 5 x x
Out[4]:= \(5x^2\)
Conditional Statement
The if contains three parts i.e. test, then (what to do if true), and else (what to do if false). The syntax is as follows
If[test, then, else]
Examples
In[1]:= If[5<8, Print["5 is less than 8"], Print["5 is more than 8"]
5 is less than 8
List
List of items are indicated by { ... }
In[1]:= {1, 2, 3} * 2
Out[1]:= {2, 4, 6}
The index of the list starts from 1
In[1]:= {3, 8, 2, 9}[[3]]
Out[1]:=2
Loop
The syntax used for the loop in Mathematica is as follows
For[start, test, incr, body]
start indicate the condition when the loop is started (initialization)
test indicate the condition to check during the loop
incr indicate the increment happen on each loop
body indicate the operation done during the loop
Example:
In[1]:= For[i=0, i<4, i++, Print[i]]
0
1
2
3
If you want to add more command on each section, separate the command using semicolon ;
Example
In[1]:= For[i = 0, i < 4, i++, Print[i]; Print["hello"]]
0
hello
1
hello
2
hello
3
hello
Data Visualisation
Plot
You can plot single function using the following command
Plot[f, {x , \(x_{min}\) , \(x_{max}\) }]
Example
In[1]:=Plot[Sin[x], {x, 0, 6 Pi}]
If you want to plot more than one functions, use list in the functions
Plot[{f1, f2, ... fn}, {x , \(x_{min}\) , \(x_{max}\) }]
Example
Plot[{Sin[x], Cos[x]}, {x, 0, 6 Pi}]
ListPlot
ListPlot function can be used to plot points. The syntax is as follows
ListPlot[{y1, y2, ... yn}]
Example
ListPlot[{1, 3, 5}]
ListLinePlot
ListLinePlot can be used to plot a line through the points. The syntax is as follows
ListLinePlot[{y1, y2, ... yn}]
Example
ListLinePlot[{1, 3, 5, 8}]
Manipulate Commands
Manipulate is used to see the changes in the output when the input is changed
Example
Manipulate[Plot[Sin[a x], {x, 0, 6}], {a, Pi, 3 Pi}]
Comments