MATRIX RENUMBER

MATRIX RENUMBER (LET)

Let Subcommand

Reorder the rows and columns of a matrix.

It is on occassion useful to reorder the rows and/or the columns of a matrix.

LET <mout> = MATRIX RENUMBER <m> <rows> <cols>
            <SUBSET/EXCEPT/FOR qualification>
where <m> is the original matrix;
<rows> is a variable containing the desired row order;
<cols> is a variable containing the desired column order;
<mout> is the matrix after the rows and columns have been reordered;
and where the <SUBSET/EXCEPT/FOR qualification> is optional (and rarely used in this context).

LET MOUT = MATRIX RENUMBER M VROWS VCOLS

None

None

READ MATRIX	=	Read a matrix.
MATRIX ADD ROW	=	Add a row to a matrix.
MATRIX COMBINE ROW	=	Combine two matrices by rows.
MATRIX COMBINE COLUMN	=	Combine two matrices by columns.

Nijenhuis and Wilf (1978), "Combinatorial Algorithms", Second Edition, Academic Press, Chapter 17.

Combinatorial Analysis

2008/05

 
.  Following example from page 157 of Nijenhuis and Wilf
DIMENSION 100 COLUMNS
READ MATRIX M
23 24 25 26 27 28 29 21 22
33 34 35 36 37 38 39 31 32
93 94 95 96 97 98 99 91 92
63 64 65 66 67 68 69 61 62
73 74 75 76 77 78 79 71 72
83 84 85 86 87 88 89 81 82
53 54 55 56 57 58 59 51 52
43 44 45 46 47 48 49 41 42
13 14 15 16 17 18 19 11 12
END OF DATA
.
LET ROWIND = DATA 2 3 9 6 7 8 5 4 1
LET COLIND = DATA 3 4 5 6 7 8 9 1 2
.
LET MOUT = MATRIX RENUMBER M ROWIND COLIND
SET WRITE DECIMALS 0
PRINT MOUT
    

The following output is generated

 
         MATRIX MOUT    --            9 ROWS
                        --            9 COLUMNS

 VARIABLES--MOUT1       MOUT2       MOUT3       MOUT4       MOUT5       MOUT6       MOUT7       MOUT8       MOUT9   

         11          12          13          14          15          16          17          18          19
         21          22          23          24          25          26          27          28          29
         31          32          33          34          35          36          37          38          39
         41          42          43          44          45          46          47          48          49
         51          52          53          54          55          56          57          58          59
         61          62          63          64          65          66          67          68          69
         71          72          73          74          75          76          77          78          79
         81          82          83          84          85          86          87          88          89
         91          92          93          94          95          96          97          98          99