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Bertini.BCMSolve

Solves a zero dimensional non-homogeneous polynomial system of equations using multi-homogenization and user configurations.
Syntax
          
Bertini.BCMSolve(P:LIST, ConfigSet:LIST)

          

Description
Please note: The function(s) explained on this page is/are using the ApCoCoAServer. You will have to start the ApCoCoAServer in order to use it/them.

This function solves a polynomial system of equations using multihomogeneous homotopy. The polynomial system of equations must be quadratic. If the system has N variables then multihomogeneous homotopy will introduce N homogeneous variables to solve the system. It uses total degree homotopy to find all isolated solutions and enables you to use all kinds of user configurations provided by Bertini. Please read about configuration settings provided in Bertini manual. The system of polynomials should be non-homogeneous. The output will be the list of all finite solutions.

Example
-- We want to solve the system x^2+y^2-5=0,xy-2=0, using multi-homogenization, for adaptive precision. 

Use S ::= QQ[x,y];            
P := [x^2+y^2-5,xy-2];
ConfigSet := ["MPTYPE: 2"];

-- Then we compute the solution with
Bertini.BCMSolve(P,ConfigSet);

-- And we achieve a list of lists containing finite solutions.
----------------------------------------
[
[
 Vector(1000000000000017/1000000000000000, 145132717332349/15625000000000000000000000000),
 Vector(49999999999999/25000000000000, -3537662353156057/100000000000000000000000000000)
],
[
 Vector(-62500000000003/62500000000000, 4415730565392687/100000000000000000000000000000),
 Vector(-499999999999983/250000000000000, -66866973306543/400000000000000000000000000)
],
[
 Vector(999999999999983/500000000000000, -1787591178181031/50000000000000000000000000000),
 Vector(1000000000000013/1000000000000000, 281412486737749/25000000000000000000000000000)
],
[ 
 Vector(-499999999999999/250000000000000, -3956938527452181/1000000000000000000000000000000),
 Vector(-9999999999999989/10000000000000000, -596634837824491/1250000000000000000000000000000)
]
]

--For Bertini output files please refer to ApCoCoA directory/Bertini.


Example
--The same example as above but this time using regeneration.
--Regeneration is an equation-by-equation method for finding the non-singular isolated solutions.
-- We want to solve the system x^2+y^2-5=0,xy-2=0, using multi-homogenization, for adaptive precision. 

Use S ::= QQ[x,y];            
P := [x^2+y^2-5,xy-2];
ConfigSet := ["USEREGENERATION: 1"];

-- Then we compute the solution with
Bertini.BCMSolve(P,ConfigSet);

-- And we achieve a list of lists containing finite solutions.
----------------------------------------
[
[
Vector(9999999999999999/10000000000000000, -643977180168769/1250000000000000000000000000000), 
Vector(2, 1660674691787513/5000000000000000000000000000000)
], 
[
Vector(-2000000000000001/1000000000000000, 584020313856301/500000000000000000000000000000),
Vector(-9999999999999999/10000000000000000, 45486167963413/125000000000000000000000000000)
],
[
Vector(2, 2989952880295369/1000000000000000000000000000000), 
Vector(9999999999999993/10000000000000000, 732258034227497/5000000000000000000000000000000)
], 
[
Vector(-1, -879366755419571/5000000000000000000000000000000), 
Vector(-2, 4460430333228999/10000000000000000000000000000000)
]
]

--For Bertini output files please refer to ApCoCoA directory/Bertini.


Example
-- We want to solve the non-homogenous polynomial system (29/16)z[1]^3 - 2z[1]z[2]=0, z[2] - z[1]^2=0, using multi-homogenization. 
-- In addition suppose we want Bertini to follow the paths very closely (correct to 8 digits before the endgame and correct to 11 
-- digits when running the endgame) and that you want the endgame to compute approximations of each solution until successive 
-- approximations agree to at least 14 digits. 

Use S ::= QQ[z[1..2]];             
P := [(29/16)z[1]^3 - 2z[1]z[2], z[2] - z[1]^2];
ConfigSet := ["TRACKTOLBEFOREEG: 1e-8", "TRACKTOLDURINGEG: 1e-11", "FINALTOL: 1e-14"];

-- Then we compute the solution with
Bertini.BCMSolve(P,ConfigSet);

-- And we achieve a list of lists containing finite solutions.
----------------------------------------
[
[
Vector(-6272142330887219272991421734532181259967888828557/2500000000000000000000000000000000000000000000000000000000000000, 
-16866585769960937068249054027382922938807741513177/100000000000000000000000000000000000000000000000000000000000000000), 
Vector(8805522460698904717783577526969974058842568093851/20000000000000000000000000000000000000000000000000000000000000000000000000,
371666764789855282623508352529304991388858172316/6250000000000000000000000000000000000000000000000000000000000000000000000000000)
],
[
Vector(2800994767392818954296004874687536350261142130669/2000000000000000000000000000000000000000000000000000000000000000, 
-10442004545151043511524382737808469250701933034019/5000000000000000000000000000000000000000000000000000000000000000), 
Vector(-16863840390941893071858292951853672304120979133893/100000000000000000000000000000000000000000000000000000000000000000000000,
-5137795605139651161672232162161044043786444504329/1250000000000000000000000000000000000000000000000000000000000000000000000000000)
], 
[
Vector(1745556907758497619927983789627389730399846491963/1250000000000000000000000000000000000000000000000000000000000000, 
28437259304210599902269601024330245142947311467321/10000000000000000000000000000000000000000000000000000000000000000), 
Vector(-43119800109410418470261587328237339500316468515037/100000000000000000000000000000000000000000000000000000000000000000000000,
11161237954525426581510768500892187905929449123739/2000000000000000000000000000000000000000000000000000000000000000000000000000000)
]
]



--For Bertini output files refer to ApCoCoA directory/Bertini.
------------------------------------------


See Also