Starting diary file diary-04-Apr-2018.txt

load ndmats
whos
  Name           Size             Bytes  Class     Attributes

  A            100x100             8168  double    sparse    
  ans           10x10               800  double              
  ap           100x100             8168  double    sparse    
  d              1x25                50  char                
  dfile          1x21                42  char                
  invp           1x100              800  double              
  invperm        1x100              800  double              
  n              1x1                  8  double              
  pnd            1x100              800  double              
  xy           100x2               1600  double              

nnz(A)
ans =
   460

spy(A)
xy
xy =
     1     1
     1     2
     1     3
     ...
    10    10

gploth(A,xy,1:100)
L = chol(A)';
figure, spy(L)
figure, etreeplotg(A,1)

size(pnd)
ans =
     1   100
pnd
pnd =
  Columns 1 through 10
   100    80    70    90    98    97    78    77    68    67
  Columns 11 through 20
    88    87    99    89    79    69    50    40    20    10
  ...
  Columns 91 through 100
    96    86    76    66    56    46    36    26    16     6

invperm(pnd) = 1:100;

invperm
invperm = ...

PND = reshape(pnd,10,10)
PND =
   100    88    30    27    95    72    45    42    43    96
    80    87    48    49    94    71    44    41    33    86
    70    99    47    39    75    62    35    32    23    76
    90    89    38    29    74    61    34    31    13    66
    98    79    37    19    65    82    15    12     3    56
    97    69    18     9    64    81    14    11    55    46
    78    50    17    60    85    93     5     2    54    36
    77    40     8    59    84    83     4     1    53    26
    68    20     7    58    92    73    25    22    52    16
    67    10    28    57    91    63    24    21    51     6

INV = reshape(invperm,10,10)
INV =
    78    76    80    74    72    90    54    52    56    50
    77    75    79    73    71    89    53    51    55    49
    85    84    83    82    81    88    60    59    58    57
    68    66    70    64    62    87    46    44    48    42
    67    65    69    63    61    86    45    43    47    41
   100    99    98    97    96    95    94    93    92    91
    29    27    31    25    23    40    10     8    12     6
    28    26    30    24    22    39     9     7    11     5
    36    35    34    33    32    38    16    15    14    13
    20    19    21    18    17    37     3     2     4     1

Ap = A(pnd,pnd);
spy(Ap)
etreeplotg(Ap,1)
diary off