In [3]:

    

v = zeros(10, 1);  % Column vector


    

In [5]:

    

for i=1:10,    % For i in 1 to 10
   v(i) = 2^i;
end
v


    

    




v =

      2
      4
      8
     16
     32
     64
    128
    256
    512
   1024

In [7]:

    

indexes = 1:10


    

    




indexes =

    1    2    3    4    5    6    7    8    9   10

In [9]:

    

for i=indexes, disp(i), end;


    

    




 1
 2
 3
 4
 5
 6
 7
 8
 9
 10

In [11]:

    

i = 1; 
while i < 5; v(i) = 100; i = i + 1; end;
v


    

    




v =

    100
    100
    100
    100
     32
     64
    128
    256
    512
   1024

In [12]:

    

i = 1;
while true,
    v(i) = 999;
    i = i + 1;
    if i == 6,
        break;
    end;
end;


    

In [13]:

    

v(1) = 2;
if v(1) == 1,
    disp('the value is one');
elseif v(1) == 2,
    disp('the value is two');
else
    disp('the value is not one or two');
end;


    

    




the value is two

In [14]:

    

% quit % exit octave


    

In [19]:

    

squareThisNumber(5)  % From squareThisNumber.m


    

    




ans =  25

In [20]:

    

pwd


    

    




ans = /home/gary/Devel/python/coursera_ml

In [21]:

    

% addpath('~/mylibs)  % add search path for modules


    

In [23]:

    

[a, b] = squareAndCubeThisNumber(5);
a
b


    

    




a =  25
b =  125

In [30]:

    

X = [1 1; 1 2; 1 3]
y = [1; 2; 3]
theta = [0; 1]


    

    




X =

   1   1
   1   2
   1   3

y =

   1
   2
   3

theta =

   0
   1

In [31]:

    

j = costfunctionJ(X, y, theta)


    

    




sqrErrors =

   0
   0
   0

j = 0

In [33]:

    

theta = [0;0]
j = costfunctionJ(X, y, theta)


    

    




theta =

   0
   0

sqrErrors =

   1
   4
   9

j =  2.3333

In [35]:

    

(1^2 + 2^2 + 3^2) / (2 * 3)  % Validate


    

    




ans =  2.3333