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confound2(basis), REAL matrix basis containing confounding generators

Keywords: confounding, design, factorial
confound2(basis) confounds a two series factorial into blocks based on
the generators given in the matrix basis.  Results are returned in a
structure with component names 'block1', 'block2', etc.  Each component
has a CHARACTER vector of factor/level combinations for that block.

The p x k matrix basis contains the generators for the confounding, one
row for each generator and one column for each factor in the design.
The elements in basis are 0 or 1.  A nonzero entry indicates that a
factor is present in the generator for that row.

  Cmd> # Matrix d is 2x4 (2 generators so 4 blocks of size 4)

  Cmd> print(d,format:"2.0f")
  (1,1)  1  1  0  0     [AB is a generator]
  (2,1)  0  1  1  1     [BCD is a generator]

  Cmd> confound2(d)
  component: block1
  (1) "(1)"
  (2) "abc"
  (3) "abd"
  (4) "cd"
  component: block2
  (1) "a"
  (2) "bc"
  (3) "bd"
  (4) "acd"
  component: block3
  (1) "ab"
  (2) "c"
  (3) "d"
  (4) "abcd"
  component: block4
  (1) "b"
  (2) "ac"
  (3) "ad"
  (4) "bcd"

See also aliases2(), choosegen2(), choosedef2().

Gary Oehlert 2003-01-15