dot

VarDict1D.dot(paramdict)

Sum the products of variables with corresponding coef from ParamDict1D, in an expression.

Assumes the coef to be zero if not found in the ParamDict1D.

Equivalent to:

xp.Sum(paramdict.get(k, 0) * v for k, v in vardict.items())

Parameters:

paramdictParamDict1D

ParamDict1D to be used for dot product.

Returns:

xp.expression

Raises:

TypeError

If the paramdict is not as instance of ParamDict1D.

Notes

This method is equivalent to using the matrix multiplication operator @.

Both ParamDict1D @ VarDict1D and VarDict1D @ ParamDict1D will also produce the same result.

Examples

Create xpress problem:

>>> import xpress as xp
>>> import warnings
>>> warnings.filterwarnings('ignore', category=xp.LicenseWarning)

>>> prob = xp.problem()

Create index-set:

>>> nodes = IndexSet1D(['A', 'B', 'C'], name='node')

Add variables:

>>> from opti_extensions.xpress import addVariables
>>> node_select = addVariables(prob, nodes, name='node-select', vartype=xp.binary)

Define parameter:

>>> from opti_extensions import ParamDict1D
>>> fixed_cost = ParamDict1D({'A': 100, 'B': 200})

Compute dot product (three alternative ways):

>>> node_select.dot(fixed_cost)
100 * node-select(A) + 200 * node-select(B)

>>> fixed_cost @ node_select
100 * node-select(A) + 200 * node-select(B)

>>> node_select @ fixed_cost
100 * node-select(A) + 200 * node-select(B)