RegularChains[ParametricSystemTools][ComplexRootClassification] - compute a classification of the complex roots of a polynomial system depending on parameters
|
Calling Sequence
|
|
ComplexRootClassification(F, d, R)
ComplexRootClassification(F, H, d, R)
ComplexRootClassification(CS, d, R)
|
|
Parameters
|
|
F
|
-
|
list of polynomials
|
H
|
-
|
list of polynomials
|
d
|
-
|
number of parameters
|
R
|
-
|
polynomial ring
|
CS
|
-
|
constructible set
|
|
|
|
|
Description
|
|
•
|
The integer d must be positive and smaller than the number of variables.
|
•
|
The characteristic of R must be zero and the last d variables of R are regarded as parameters.
|
•
|
For a parametric algebraic system, this command computes all the possible numbers of solutions of this system together with the corresponding necessary and sufficient conditions on its parameters.
|
•
|
More precisely, let V be the variety defined by F. The command ComplexRootClassification(F, d, R) returns a classification of the complex roots of F depending on parameters, that is, a finite partition P of the parameter space into constructible sets such that above each part, the number of solutions of V is either infinite or constant.
|
•
|
If a constructible set CS is specified, the representing regular systems of CS must be square-free. The function call ComplexRootClassification(CS, d, R) returns a classification of the points of the constructible set CS, that is, a finite partition P of the parameter space into constructible sets such that above each part, the number of solutions of CS is either infinite or constant.
|
•
|
If H is specified, let be the variety defined by the product of polynomials in H. The command ComplexRootClassification(F, H, d, R) returns a classification of the points of the constructible set V-W depending on parameters.
|
|
|
Examples
|
|
>
|
|
>
|
|
>
|
|
>
|
|
| (1) |
>
|
|
| (2) |
The computation below shows that the input parametric system can have 1 solution or 2 distinct solutions. The corresponding conditions on the parameters are given by constructible sets.
>
|
|
| (3) |
These constructible sets are printed below.
>
|
|
| (4) |
|
|
Download Help Document
Was this information helpful?