% Matlab diary from CS 240A, Thursday, January 16, 2014

what

M-files in the current directory /Users/gilbert/Documents/CS240aWinter2014/Matlab

startup    

cd temperature
what

M-files in the current directory /Users/gilbert/Documents/CS240aWinter2014/Matlab/temperature

jacobi    

MAT-files in the current directory /Users/gilbert/Documents/CS240aWinter2014/Matlab/temperature

heatproblem      

load heatproblem
whos
  Name          Size                Bytes  Class     Attributes
  A         10000x10000            873608  double    sparse    
  ans           1x48                   96  char                
  b         10000x1                 80000  double              

nnz(A)
ans =
       49600
spy(A)
A
A =
         (1,1)              4
         (2,1)             -1
       (101,1)             -1
         (1,2)             -1
         (2,2)              4
         (3,2)             -1
       (102,2)             -1
         (2,3)             -1
...
      (9899,9999)          -1
      (9998,9999)          -1
      (9999,9999)           4
     (10000,9999)          -1
      (9900,10000)         -1
      (9999,10000)         -1
     (10000,10000)          4
b
b'
ans =
  Columns 1 through 16
     0     0     0     0     0     0     0     0     0     0     0     0     0     0     0     0
  Columns 17 through 32
     0     0     0     0     0     0     0     0     0     0     0     0     0   100   100   100
  Columns 33 through 48
   100   100   100   100   100   100   100   100   100   100   100   100   100   100   100   100
  Columns 49 through 64
   100   100   100   100   100   100   100   100   100   100   100   100   100   100   100   100
  Columns 65 through 80
   100   100   100   100   100   100     0     0     0     0     0     0     0     0     0     0
  Columns 81 through 96
     0     0     0     0     0     0     0     0     0     0     0     0     0     0     0     0
  ...
  Columns 9969 through 9984
     0     0     0     0     0     0     0     0     0     0     0     0     0     0     0     0
  Columns 9985 through 10000
     0     0     0     0     0     0     0     0     0     0     0     0     0     0     0     0
plot(b)


t = A \ b;
t
t =
    0.0588
    0.1181
    0.1784
    0.2402
    0.3040
...
    0.0125
    0.0063
max(t)
ans =
   96.6666
min(t)
ans =
    0.0063
T = reshape(t,100,100);
size(T)
ans =
   100   100
surfc(T)