QuantifierElimination[CADData]
GetCells
CADData method to get all the leaf cells for a CAD
Calling Sequence
Parameters
Returns
Description
Examples
Compatibility
GetCells( cad, truthvalue = t, output = o )
cad
-
CADData object from a QE or CAD computation.
t
(optional) truefalse; defines a filter such that only cells with the truth value t are returned. (default FAIL which defines no filtering)
o
(optional) a list of symbols including cells, samplepoints and descriptions. This customizes the output of this method as described in the description. (default FAIL, with return value as described below)
By default, i.e. without specification of the keyword option o, a list of cells for the CAD is returned.
Otherwise, returns a list of outputs (list of lists) corresponding to the elements specified in the list passed as value for output:
cells : list(CADCell); list of CAD cells for the CAD.
samplepoints : list of lists; each inner list is a sample point for the corresponding cell, of the form name = realalgnum.
descriptions : list of quantifier free formulae; a relation or conjunction of relations describing the boundaries of the cell in n-space (where the CAD is in n variables).
The GetCells⁡cad calling sequence produces a list of all leaf CADCells for the CAD cad. By leaf CAD cell we mean one which either could not or did not need to be subdivided into further cells.
Usage of the o keyword option customizes the output such that the most interesting properties of CADCells may be accessed more directly without intermediate calls to e.g. map that would be needed in usage of the default calling sequence when intending to access said properties such as sample points as the end goal.
ex≔:-exists⁡y,x,:-And⁡3⁢x2−2⁢y<0,0<x−y,0<y+2
ex≔∃⁡y,x,3⁢x2−2⁢y<0∧0<x−y∧0<y+2
cad≔QuantifierElimination:-PartialCylindricalAlgebraicDecompose⁡ex,output=data
cad≔Variables=⁢x,yInput Formula=⁢∃⁡x,y,3⁢x2−2⁢y<0∧−x+y<0∧−y<2# Cells=⁢29Projection polynomials for level 1=⁢x2+x3⁢x−23⁢x2+4Projection polynomials for level 2=⁢x−yy+23⁢x2−2⁢y
cells≔GetCells⁡cad:
cells1..5
Description=⁢x<−2∧y<xSample Point=⁢x=−3,y=−4Index=⁢1,1,Description=⁢x<−2∧y=xSample Point=⁢x=−3,y=−3Index=⁢1,2,Description=⁢x<−2∧x<y∧y<−2Sample Point=⁢x=−3,y=−52Index=⁢1,3,Description=⁢x<−2∧y=−2Sample Point=⁢x=−3,y=−2Index=⁢1,4,Description=⁢x<−2∧−2<y∧y<3⁢x22Sample Point=⁢x=−3,y=0Index=⁢1,5
trueSamplePoints≔GetCells⁡cad,truthvalue=true,output=samplepoints
trueSamplePoints≔x=12,y=25
GetCells⁡cad,truthvalue=true,output=descriptions
0<x∧x<23∧3⁢x22<y∧y<x
The QuantifierElimination:-CADData:-GetCells command was introduced in Maple 2023.
For more information on Maple 2023 changes, see Updates in Maple 2023.
The output option was introduced in Maple 2024.
For more information on Maple 2024 changes, see Updates in Maple 2024.
See Also
CADCell
CADData
CylindricalAlgebraicDecompose
PartialCylindricalAlgebraicDecompose
QEData
QuantifierElimination
QuantifierElimination options
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