subtable -- extract a subtable from a table

Synopsis

• Usage:

  subtable(a, b, T)

• Inputs:
  • a, a list, of rows to extract
  • b, a list, of columns to extract
• Outputs:
  • S, the subtable of $T$ defined by restricting to rows in the list $a$ and columns in the list $b$

Description

i1 : t = table({1,3,5,7}, {0,1,2,4}, (i,j) -> i^j);

i2 : netList t

     +-+-+--+----+
o2 = |1|1|1 |1   |
     +-+-+--+----+
     |1|3|9 |81  |
     +-+-+--+----+
     |1|5|25|625 |
     +-+-+--+----+
     |1|7|49|2401|
     +-+-+--+----+

i3 : s1 = subtable({0,2}, {1,3}, t);

i4 : netList s1

     +-+---+
o4 = |1|1  |
     +-+---+
     |5|625|
     +-+---+

i5 : s2 = subtable(toList(0..3), {1}, t);

i6 : netList s2

     +-+
o6 = |1|
     +-+
     |3|
     +-+
     |5|
     +-+
     |7|
     +-+

See also

• applyTable -- apply a function to each element of a table
• isTable -- whether something is a list of lists of equal length
• positions -- which elements of a list satisfy a condition
• table -- make a table from a binary function
• select -- select from a list, hash table, or string
• lists and sequences -- a detailed overview of lists and sequences in Macaulay2