problem.adddfs
problem.adddfs |
Purpose
Add a set of distribution factors
Synopsis
problem.adddfs(colindex, rowindex, value)
Arguments
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colindex
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Array of columns (i.e.
xpress.var objects, indices, or names) whose distribution factor is to be changed.
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rowindex
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Array of rows (i.e.
xpress.constraint objects, indices, or names) where each distribution factor applies.
|
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value
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Array holding the new values of the distribution factors.
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Example
The following example adds distribution factors as follows:
column 282 in row 134 = 0.1
column 282 in row 136 = 0.15
column 285 in row 133 = 1.0.
column 282 in row 134 = 0.1
column 282 in row 136 = 0.15
column 285 in row 133 = 1.0.
colindex = [282, 282, 285] rowindex = [134, 136, 133] value = [0.1, 0.15, 1] p.adddfs(colindex,rowindex,value)
Further information
The distribution factor of a column in a row is the matrix coefficient of the corresponding delta vector in the row. Distribution factors are used in conventional recursion models, and are essentially normalized first-order derivatives. Xpress SLP can accept distribution factors instead of initial values, provided that the values of the variables involved can all be calculated after optimization using determining rows, or by a callback.
The problem.adddfs functions load additional items into the SLP problem. The corresponding problem.loaddfs functions delete any existing items first.
Related topics