DStart
| Type: | double |
|---|---|
| Modifiable: | Yes |
The current simplex start vector. If you set DStart values
for every linear constraint in the model and
PStart values for every
variable, then simplex will use those values to compute a warm start
basis. If you'd like to retract a previously specified start, set any
DStart value to GRB_UNDEFINED.
Note that any model modifications made after setting DStart
(adding variables or constraints, changing coefficients, etc.) will
discard the start. You should only set this attribute after you are
done modifying your model.
Note also that you'll get much better performance if you warm start
your linear program from a simplex basis (using
VBasis and
CBasis). The DStart
attribute should only be used in situations where you don't have a
basis.
If you'd like to provide a feasible starting solution for a MIP model, you should input it using the Start attribute.
Only affects LP models; it will be ignored for QP, QCP, or MIP models.
Note that if you provide a valid starting extreme point, either through PStart, DStart, or through VBasis, CBasis, then LP presolve will be disabled. For models where presolve greatly reduces the problem size, this might hurt performance.
For examples of how to query or modify attributes, refer to our Attribute Examples.
