Next: Possible parameters values for
Up: Parametric polynomial
Previous: The WeylFilter procedure
Contents
The basic procedures for computing the minimal and maximal roots of a
parametric polynomial are:
MinMax_Polynom(Func,Vars,Init,Type,Solve,Rand,Points,Min,Pm,Max,PM)
MinMax_Polynom_Gradient(Func,Vars,Init,Type,Solve,Rand,Points,Min,Pm,Max,PM)
where
- Func: the list of constraints between the parameters and
polynomial unknown. The polynomial must be the last element of this
list. If this last element is a matrix then the considered polynomial
is the characteristic polynomial of the matrix (but this is not the
more efficient procedure for this case, see next section). If this
last argument is Fast_CharPoly(S),Medium_CharPoly(S)
or Slow_CharPoly(S)
where S is a matrix the polynomial is the
characteristic polynomial of the matrix but this polynomial will not
be computed by Maple. Instead the
procedure Coeff_CharPoly
will
be used to compute the coefficients of the polynomial: this may be
interesting for relatively large matrix.
- Vars:a list giving the name of the unknown starting with
the name of the polynomial unknown
- Init: a list of ranges for the unknown starting with the
range for the polynomial unknown (this element should be set to a
large interval and is updated automatically) followed by the ranges
for the parameters
- Type: 0 to find only the minimal root, 1 to find only
the maximal root and 2 to find both.
- Solve: a flag that should usually be set to 3, see the
on-line help
- Rand, Points: the equivalent of the rand and
Nb_Points arguments of the C++ procedure
ALIAS_Min_Max_EigenValues, see the ALIAS-C++ manual
- Min, Max: minimum and maximum root
- Pm,PM: values of the parameters at which the
minimum and maximum have been obtained
The difference between these two procedures is that the second one
uses the derivatives of the polynomial with respect to the variables
together with the derivative of the coefficients of the polynomial.
For these procedures the flag `ALIAS/stop_opt_sol`,
`ALIAS/opt_sol_max` will play the same role than Stop, Seuil[0] and Seuil[1] of the C++ procedure ALIAS_Min_Max_EigenValues, see the ALIAS-C++ reference manual.
In the special case where the polynomial is the characteristic
polynomial it may be interesting to use the specific procedures:
MinMax_Char_Poly(Func,Vars,Init,Type,Solve,Rand,Points,Min,Pm,Max,PM)
MinMax_Char_Poly_Gradient(Func,Vars,Init,Type,Solve,Rand,Points,Min,Pm,Max,PM)
which has the same argument that the previous procedures except that
the last argument of Func must be a matrix.
Next: Possible parameters values for
Up: Parametric polynomial
Previous: The WeylFilter procedure
Contents
Jean-Pierre Merlet
2012-12-20