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SubalgebraBases :: extractEntries

extractEntries -- Inverse of moduleToSubringIdeal

Synopsis

Description

Converts elements of a subring ideal (represented by a one-column matrix and usually generated by moduleToSubringIdeal) to elements of a module (represented by a matrix).

Internally, the argument gVars is sorted so that the order of the columns of the resulting matrix are consistent.

i1 : R = QQ[a, b, c, x_1, x_2, x_3];
i2 : extractEntries(matrix {{a*x_1 + b*x_2 + c*x_3}}, matrix {{x_1, x_2, x_3}})

o2 = | c b a |

             1       3
o2 : Matrix R  <--- R
i3 : extractEntries(matrix {{a*x_1 + b*x_2 + c*x_3},{a*x_1 + a*x_2 + a*x_3}}, matrix {{x_1, x_2, x_3}} )

o3 = | c b a |
     | a a a |

             2       3
o3 : Matrix R  <--- R

See also

Ways to use extractEntries :

For the programmer

The object extractEntries is a method function.