clear: clear all variables and functions from memory
clear a b c: clear variables a,b and c
format long/short: gives 15/5 digit output e.g.
>> format short
>> pi
ans =
3.1416
>> format long
>> pi
ans =
3.14159265358979
>>
who or whos: checks on currently defined variables e.g.
>> a=[1 2 3; 4 5 6]
a =
1 2 3
4 5 6
>> whos a
Name Size Bytes Class
a 2x3 48 double array
Grand total is 6 elements using 48 bytes
which means that the variable a is a double-precision array
(each element has roughly
sixteen significant figures) with two rows and three columns.