% Matlab diary from cs111, Oct 17 2007.
%
% This is what I typed in class.  
%
% Type it into Matlab yourself to
% reproduce the output I showed.

diary on
load temperature
size(A100)
prod(ans)
8*ans
spy(A100)
nnz(A100)
whos
[L,U,P] = lu(A100);
whos
nnz(P)
nnz(L)
nnz(U)
whos
[L,U,P] = lu(A4);
whos
B = sparse(A4);
C = full(B);
whos
A4
P

clc
clear
whos

[U,G] = surfer('http://cs.ucsb.edu',50);
%% Note: you can also get U and G by 
%% putting "ucsbmat2007.mat" from the course web page in your directory
%% and saying "load ucsbmat2007" to Matlab

whos
U
U(25)
G(25,25)
G(25,26)
U(3)
x = zeros(50,1)
x(3)=1
nnz(x)
x(3)
size(G)
G*x
sparse(G*x)
G(:,3)
y = sparse(G*x)
y = y / sum(y)
z = G * y
z = z / sum(z)
sum(z)
clc
size(G)
c = sum(G);
size(c)
c
nnz(c)
find(c == 0)
G(:,13)
x = zeros(50,1);
x(13)=1;
sparse(x)
sparse(G*x)
G = G | speye(50);
help speye
help eye
spy(G)
E = ones(5)
x = rand(5,1)
y = E*x
y = y / sum(y)
clc

e = ones(50,1)
size( e * e')
clc
c = sum(G);
c
size(c)
c = sparse( 1 ./ c);
size(c)
D = diag(c);
size(D)
nnz(D)
figure, spy(D)
GD = G*D;
s = sum(GD);
s
diary off