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leftKernelWeightEDDegree -- numerically compute Euclidean distance degrees of complete intersections

Description

This method computes Euclidean distance (ED) degrees for affine varieties defined by the system $F$ numerically using Lagrange multipliers. If the resulting variety is a complete intersection, the left kernel of the augmented Jacobian is used to derive a set of critical erquations which are passed into Bertini. The resulting number of critical points is returned as the ED degree. The unit variant of this method computes an ED degree using random (complex) data and unit weights, whereas `leftKernelGenericEDDegree` will use random data and random weights.

i1 : R = QQ[x,y];
i2 : F = {x^2 + y^2 - 1};
i3 : (U,W) = ({.12, .23}, {.15, .331});
i4 : UED = leftKernelUnitEDDegree F
Warning: The HomVariableGroup is written first and then the AffVariableGroup is written second.

o4 = 2
i5 : GED = leftKernelGenericEDDegree F
Warning: The HomVariableGroup is written first and then the AffVariableGroup is written second.

o5 = 4
i6 : GED = leftKernelWeightEDDegree(F, U, W)
Warning: The HomVariableGroup is written first and then the AffVariableGroup is written second.

o6 = 4

Caveat

The computed ED degree may be lower than expected due to path tracking.

Menu

Ways to use leftKernelWeightEDDegree:

  • leftKernelWeightEDDegree(List,List,List)

For the programmer

The object leftKernelWeightEDDegree is a method function with options.


The source of this document is in /build/reproducible-path/macaulay2-1.26.06+ds/M2/Macaulay2/packages/EuclideanDistanceDegree.m2:339:0.