% Practical 1, Subject 3: sub3p1.m
 x=10;
 y= 'alex';       % y is a 1x4 matrix
 whos
a = [ 1 2 3 4 ; 5 6 7 8; 9 10 11 12]  
length(a)
size(a)
size(a,1)
size(a,2)
ndims(a)
numel(a)
transpose(a) %
a.';         % also
a' ;         % sometimes   
 a(2,3)       
 a(2,3)=70  
 a(end, end)  
prod(a)
prod(a')
sum(a)
sum(a')
prod(size(a))
numel(a)
diag(a)
diag(diag(a))

 a(10,10)=100
