public abstract class AbstractWeightedPatternextends Object
implements WeightedPattern
A skeletal implementation of the WeightedPattern interface to minimize
the effort required to implement this interface.
This implementation is based on using some "parent" pattern, implementing Pattern interface
and passed to the constructor.
All methods of this class, excepting declared in the WeightedPattern interface,
just call the same methods of the parent pattern.
To complete implementation, you just need to implement several methods from
the WeightedPattern interface.
Returns a non-empty list of all best or almost best
union decompositions
with equal or similar "quality",
i.e. with the same or almost same summary number of points in all Minkowski decompositions
of all returned patterns.
Returns the maximal boundary of this pattern along the given axis:
a pattern consisting of all points of this pattern, for which there are
no other points with greater coordinate #coordIndex
and same other coordinates.
Returns the minimal boundary of this pattern along the given axis:
a pattern consisting of all points of this pattern, for which there are
no other points with less coordinate #coordIndex
and same other coordinates.
Returns the Minkowski decomposition:
a non-empty list of patterns P0, P1, ..., Pn−1,
such that this pattern P (the point set represented by it)
is a Minkowski sum of them (of the point sets represented by them):
P = P0 ⊕ P1 ⊕...⊕ Pn−1.
Returns the pattern consisting of points, generated from points of this instance
by multiplying on the mult argument via IPoint.multiply(double) method.
Returns the same result as Pattern.coordArea() method,
but all minimal and maximal coordinates are rounded to integer values
by StrictMath.round operation.
Returns the same result as Pattern.coordRange(int coordIndex) method,
but both minimal and maximal coordinates are rounded to integer values
by StrictMath.round operation.
Returns the pattern shifted by the argument, that is consisting of points
with the same weights,
generated from points of this instance by adding the argument via IPoint.add(IPoint) method.
Returns a union decomposition:
a non-empty list of patterns P0, P1, ..., Pn−1,
such that this pattern P (the point set represented by it)
is the set-theoretical union of them (of the point sets represented by them):
P = P0 ∪ P1 ∪...∪ Pn−1.
Returns the number of points in this pattern.
This value is always positive (>=1).
If the number of points is greater than Long.MAX_VALUE, returns Long.MAX_VALUE.
Warning! This method can work slowly for some forms of large patterns:
the required time can be O(N), where N is the number of points (result of this method).
In these cases, this method can also throw TooManyPointsInPatternError
or OutOfMemoryError.
There is a guarantee, that if this object implements QuickPointCountPattern interface,
then this method works very quickly (O(1) operations) and without exceptions.
There is a guarantee, that if this object implements DirectPointSetPattern interface,
then the result of this method is not greater than Integer.MAX_VALUE.
Note: if this method returns some value greater than Integer.MAX_VALUE,
it means that you cannot use Pattern.points() and Pattern.roundedPoints() methods,
because Java Set object cannot contain more than Integer.MAX_VALUE elements.
Returns the number of points in this pattern as double value.
In particular, if the result of Pattern.pointCount() method is not greater than Long.MAX_VALUE,
there is a guarantee that this method returns the same result, cast to double type.
Warning! This method can work slowly for some forms of large patterns:
the required time can be O(N), where N is the number of points (result of this method).
In these cases, this method can also throw TooManyPointsInPatternError
or OutOfMemoryError.
There is a guarantee, that if this object implements QuickPointCountPattern interface,
then this method works very quickly (O(1) operations) and without exceptions.
The result of this method is immutable (Collections.unmodifiableSet).
Moreover, the result is always the same for different calls of this method for the same instance —
there are no ways to change it, in particular, via any custom methods of the implementation class
(it is a conclusion from the common requirement, that all implementations of this interface must be
immutable).
The returned set is always non-empty,
and the number of its elements is always equal to Pattern.pointCount().
Warning! This method can work slowly for some forms of large patterns.
In these cases, this method can also throw TooManyPointsInPatternError
or OutOfMemoryError.
This method surely fails (throws one of these exception), if the total number of points
Pattern.pointCount()>Integer.MAX_VALUE, because Java Set object
cannot contain more than Integer.MAX_VALUE elements.
For example, implementations of the rectangular patterns
allow to successfully define a very large 3D parallelepiped
n x n x n.
Fur such pattern, this method will require a lot of memory
for n=1000 and will fail (probably with TooManyPointsInPatternError)
for n=2000 (20003>Integer.MAX_VALUE).
Returns the set of all integer points, obtained from the points of this pattern
(results of points() method by rounding with help of
Point.toRoundedPoint() method.
In other words, the results of this method is the same as the result of the following code:
Set<IPoint> result = new HashSet<IPoint>(); // or another Set implementation
for (Point p : points()) {
result.add(p.toRoundedPoint());
}
result = Collections.unmodifiableSet(result);
The result of this method is immutable (Collections.unmodifiableSet).
Moreover, the result is always the same for different calls of this method for the same instance —
there are no ways to change it, in particular, via any custom methods of the implementation class
(it is a conclusion from the common requirement, that all implementations of this interface must be
immutable).
The returned set is always non-empty.
Note: the number of resulting points can be less than Pattern.pointCount(), because some
real points can be rounded to the same integer points.
Returns the minimal and maximal coordinate with the given index
(Point.coord(coordIndex))
among all points of this pattern.
The minimal coordinate will be r.min(),
the maximal coordinate will be r.max(),
where r is the result of this method.
There is a guarantee, that if this object implements RectangularPattern interface,
then this method works very quickly (O(1) operations) and without exceptions.
Moreover, all patterns, implemented in this package, have very quick implementations of this method
(O(1) operations). Also, the implementations of this method in this package never throw exceptions.
It is theoretically possible, that in custom implementations of this interface
(outside this package) this method will work slowly, up to O(N) operations,
N is the number of points in this pattern.
However, even in such implementations this method must not lead to
TooManyPointsInPatternError / OutOfMemoryError, like Pattern.points() method.
Returns the minimal and maximal coordinates
among all points of this pattern for all dimensions.
If a is the result of this method,
then a.coordCount()==dimCount()
and a.range(k)
is equal to coordRange(k) for all k.
For example, in 2-dimensional case the result is
the circumscribed rectangle (with sides, parallel to the axes).
Returns the point, each coordinate of which
is equal to the minimal corresponding coordinate
among all points of this pattern.
Equivalent to Pattern.coordArea().min().
Returns the point, each coordinate of which
is equal to the maximal corresponding coordinate
among all points of this pattern.
Equivalent to Pattern.coordArea().max().
Returns true if this pattern consists of the single point, i.e.
if pointCount()==1.
There are no strict guarantees that this method always returns true if the pattern
consist of the single point. (In some complex situations, such analysis can
be too difficult. In particular, if the pattern is a Minkowski sum, then limited floating-point precision can lead to equality of all points of the result.
Simple example: a Minkowski sum of two-point one-dimensional pattern, consisting of points
0.0 and 0.000001, and one-point 251=2251799813685248.0, contains only 1 point 251,
because the computer cannot represent precise value 2251799813685248.000001 in double type
and rounds it to 2251799813685248.0.
In such situations, this method sometimes may incorrectly return false.)
But there is the reverse guarantee: if this method returns true,
the number of points in this pattern is always 1.
Unlike Pattern.pointCount() method, there is a guarantee that this method
never works very slowly and cannot lead to TooManyPointsInPatternError / OutOfMemoryError.
In situations, when the number of points is very large
(and, so, Pattern.pointCount() method is not safe in use),
this method must detect this fact in reasonable time and return false.
There is a guarantee, that if this object implements QuickPointCountPattern interface,
then this method works very quickly (O(1) operations) and absolutely correctly
(always returns true if and only if pointCount()==1).
Returns true if this pattern consists of the single point and
this point is the origin of coordinates.
There are no strict guarantees that this method always returns true if the pattern
consist of the single point, equal to the origin of coordinates. (In some complex situations, such analysis can
be too difficult. In such situations, this method may incorrectly return false.)
But there is the reverse guarantee: if this method returns true,
the number of points in this pattern is always 1 and its only point is the origin of coordinates,
in terms of Point.isOrigin() method.
Unlike Pattern.pointCount() method, there is a guarantee that this method
never works very slowly and cannot lead to TooManyPointsInPatternError / OutOfMemoryError.
In situations, when the number of points is very large
(and, so, Pattern.pointCount() method is not safe in use),
this method must detect this fact in reasonable time and return false.
There is a guarantee, that if this object implements QuickPointCountPattern interface,
then this method works very quickly (O(1) operations) and absolutely correctly.
Returns the projection of this pattern along the given axis.
The number of dimensions in the resulting pattern (Pattern.dimCount()) is less by 1, than in this one.
More precisely, the resulting pattern consists of the points,
obtained from all points of this pattern by the call
point.projectionAlongAxis(coordIndex).
There is a guarantee, that this method does not try to allocate much more memory,
that it is required for storing this pattern itself, and that it
never throws TooManyPointsInPatternError.
For comparison, an attempt to do the same operation via getting all points (Pattern.points() method),
correcting them and forming a new pattern via Patterns.newPattern(java.util.Collection)
will lead to TooManyPointsInPatternError / OutOfMemoryError for some forms of large patterns.
Returns true if this pattern is integer:
all coordinates of all points of this pattern are integer numbers.
In other words, it means that for each real (double) coordinate x of each point
of this pattern the Java expression x==(long)x is true.
More precisely, if this method returns true, then there are the following guarantees:
However, there are no strict guarantees that this method always returns true if the pattern
is really integer. In other words, if this method returns false, there is no guarantee, that
this pattern really contains some non-integer points — but it is probable.
Unlike Pattern.points() method, there is a guarantee that this method
never works very slowly and cannot lead to TooManyPointsInPatternError / OutOfMemoryError.
In situations, when the number of points is very large
and there is a risk to fail with TooManyPointsInPatternError / OutOfMemoryError,
this method must detect this fact in reasonable time and return false.
Returns this pattern, every point of which is rounded to the nearest integer point.
The result is always ordinary integer pattern
(see the comments to this interface, section "Uniform-grid patterns").
More precisely, the resulting pattern:
consists of all points,
obtained from all points of this pattern by rounding by the call
point.toRoundedPoint().toPoint();
There is a guarantee, that if this object implements RectangularPattern interface,
then this method works quickly (O(1) operations) and without exceptions.
It is an important difference from Pattern.points() and Pattern.roundedPoints() method.
Returns the minimal boundary of this pattern along the given axis:
a pattern consisting of all points of this pattern, for which there are
no other points with less coordinate #coordIndex
and same other coordinates.
The number of dimensions in the resulting pattern (Pattern.dimCount()) is the same as in this one.
In other words, this method removes some points from this pattern according the following rule:
if this pattern contains several points p0, p1, ...,
pm−1 with identical projection to the given axis
(pi.projectionAlongAxis(coordIndex).equals(pj.projectionAlongAxis(coordIndex)) for all i, j),
then the resulting pattern contains only one from these points, for which
the given coordinate coord(coordIndex) has the minimal value.
There is a guarantee, that if this object implements RectangularPattern interface,
then this method works quickly (O(1) operations) and without exceptions.
Returns the maximal boundary of this pattern along the given axis:
a pattern consisting of all points of this pattern, for which there are
no other points with greater coordinate #coordIndex
and same other coordinates.
The number of dimensions in the resulting pattern (Pattern.dimCount()) is the same as in this one.
In other words, this method removes some points from this pattern according the following rule:
if this pattern contains several points p0, p1, ...,
pm−1 with identical projection to the given axis
(pi.projectionAlongAxis(coordIndex).equals(pj.projectionAlongAxis(coordIndex)) for all i, j),
then the resulting pattern contains only one from these points, for which
the given coordinate coord(coordIndex) has the maximal value.
There is a guarantee, that if this object implements RectangularPattern interface,
then this method works quickly (O(1) operations) and without exceptions.
for any m=1,2,...,n and for any positive integer
k≤2m−1, we have
(2m−1+k)⊗P =
(2m−1⊗P) ⊕ kC.
Here A⊕B means the Minkowski sum of patterns A and B,
k⊗P means P⊕P⊕...⊕P (k summands),
and kP means the pointwise geometrical multiplication of the pattern P by the multiplier k,
i.e. P.multiply(k).
This method tries to find the minimal carcass, consisting of as little as possible number of points,
and the maximal value n, for which the formulas above are correct for the found carcass.
(The value 2n is called the maximal carcass multiplier
and is returned by Pattern.maxCarcassMultiplier() method.)
For example, for rectangular patterns this method returns
the set of vertices of the hyperparallelepiped (in one-dimensional case, the pair of segment ends),
and the corresponding n=+∞.
But this method does not guarantee that the returned result is always the minimal possible carcass
and that the found n is really maximal for this carcass.
This method allows to optimize calculation of the point set of a Minkowski multiple k⊗P.
It is really used in the pattern implementations, returned
by Patterns.newMinkowskiMultiplePattern(Pattern, int) method:
the result of that method is not always an actual Minkowski sum of N equal patterns,
but can be (in the best case) an equal Minkowski sum of ~log2N patterns
P ⊕ C ⊕ 2C ⊕ ... ⊕ 2mC
⊕ (N−2mC),
2m<N≤2m+1,
or (in not the best case, when N is greater than the maximal carcass multiplier 2n)
can be another, not so little Minkowski sum.
In the worst case (no optimization is possible), this method just returns this object (C=P),
and Pattern.maxCarcassMultiplier() returns 2 (i.e. n=1).
The returned pattern has the same number of dimensions (Pattern.dimCount()) as this one.
Returns the maximal multiplier k, for which the calculation of
the Minkowski multiple k⊗P can be optimized by using the carcass of this pattern P.
Please see Pattern.carcass() method for more information.
Note: the returned value is always ≥2. If the correct value is greater than Integer.MAX_VALUE
(for example, for rectangular patterns),
this method returns Integer.MAX_VALUE; in all other cases the returning value is a power of two.
This method can require some time and memory for execution,
but never throws TooManyPointsInPatternError.
Usually an implementation caches the results of Pattern.carcass() and this methods,
so this method works very quickly after the first call of Pattern.carcass().
Calculates and returns the Minkowski sum of this and specified patterns.
Briefly, the returned pattern consists of all points a+b, where
a is any point of this pattern, b is any point of the argument "added"
and "+" means a vector sum of two points
(the result of "a.add(b)" call).
Please see details in
Wikipedia.
Warning! This method can work slowly for some forms of large patterns.
In these cases, this method can also throw TooManyPointsInPatternError
or OutOfMemoryError.
The returned pattern always implements RectangularPattern
if this pattern and subtracted argument implement RectangularPattern
and both patterns have identical steps
(i.e. thisPattern.stepsOfGridEqual(subtracted) returns true).
In this case, this method works very quickly and without
TooManyPointsInPatternError / OutOfMemoryError exceptions.
Please draw attention: there is another way to build a Minkowski sum,
namely the method Patterns.newMinkowskiSum(java.util.Collection).
That method does not perform actual calculations and returns a special implementation
of this interface (see comments to this interface, section "Complex patterns").
Unlike that method, this one tries to actually calculate the Minkowski sum, saving (when possible)
the type of the original pattern: see above two guarantees about DirectPointSetPattern
and RectangularPattern types. If it is impossible to represent the Minkowski sum
by Java class of this pattern, it is probable that the result will be constructed
as DirectPointSetUniformGridPattern or as SimplePattern.
Calculates and returns the erosion of this pattern by specified pattern
or null if this erosion is the empty set.
Briefly, the returned pattern consists of all such points p,
that for any points b of the "subtracted" pattern the vector sum of two points
p+b
(the result of "p.add(b)" call)
belongs to this pattern.
Please see more details in
Wikipedia and
Google about the "Erosion" and "Minkowski subtraction" terms.
Warning! This method can work slowly for some forms of large patterns.
In these cases, this method can also throw TooManyPointsInPatternError
or OutOfMemoryError.
Warning: this method can fail with TooLargePatternCoordinatesException, if some of new points
violate restrictions, described in the comments to this interface,
section "Coordinate restrictions". But it is obvious, that this exception
is impossible if the passed pattern "subtracted" contains the origin of coordinates
(in this case, the result is a subset of this pattern).
The returned pattern always implements RectangularPattern
if this pattern and subtracted argument implement RectangularPattern
and both patterns have identical steps
(i.e. thisPattern.stepsOfGridEqual(subtracted) returns true).
In this case, this method works very quickly and without
TooManyPointsInPatternError / OutOfMemoryError exceptions.
Returns the Minkowski decomposition:
a non-empty list of patterns P0, P1, ..., Pn−1,
such that this pattern P (the point set represented by it)
is a Minkowski sum of them (of the point sets represented by them):
P = P0 ⊕ P1 ⊕...⊕ Pn−1.
In other words, each point p∈P of this pattern is equal to a vector sum
of some n points
p0, p1, ..., pn−1,
where pi∈Pi.
Please see Wikipedia
about the "Minkowski sum" term.
This method tries to find the best decomposition, that means the list of patterns
with minimal summary number of points. For good pattern, the returned patterns list
can consist of O(log2N) points (sum of Pattern.pointCount()
values for all returned patterns),
where N is the number of points (Pattern.pointCount()) in this pattern.
For example, a linear one-dimensional segment {x: 0<=x<2m}
is a Minkowski sum of m point pairs {0, 2i}, i=0,1,...,m-1.
There is no guarantee that this method returns a good decomposition.
If this method cannot find required decomposition, it returns the 1-element list containing
this instance as the only element.
If the number of points in this pattern is less than the argument, i.e.
Pattern.pointCount()<minimalPointCount, then this method probably does not
decompose this pattern and returns the 1-element list containing this instance as its element.
But it is not guaranteed: if the method "knows" some decomposition, but estimation of the number of points
can require a lot of resources, this method may ignore minimalPointCount argument.
However, there is a guarantee that if the number of points is 1 or 2,
i.e. Pattern.pointCount()≤2, then this method always returns
the 1-element list containing this instance as its element.
There is a guarantee that the elements of the resulting list cannot be further decomposed:
this method, called for them with the same or larger minimalPointCount argument,
always returns a list consisting of one element.
The number of space dimensions in all returned patterns (Pattern.dimCount() is the same as in this one.
The result of this method is immutable (Collections.unmodifiableList).
Returns a union decomposition:
a non-empty list of patterns P0, P1, ..., Pn−1,
such that this pattern P (the point set represented by it)
is the set-theoretical union of them (of the point sets represented by them):
P = P0 ∪ P1 ∪...∪ Pn−1.
This method tries to find such decomposition, that all patterns Pi have good
Minkowski decompositions
and the summary number of points in all Minkowski decompositions
Pi.minkowskiDecomposition(minimalPointCount)
of all patterns, returned by this method, is as small as possible —
usually much less than the number of points in this instance.
If this pattern already has a good Minkowski decompositions,
this method should return the 1-element list containing
this instance as the only element.
If the number of points in this pattern is less than the argument, i.e.
Pattern.pointCount()<minimalPointCount, then this method probably does not
decompose this pattern and returns the 1-element list containing this instance as its element.
Moreover, this method tries to build such decomposition, that every element Pi
in the resulting list contains ≥minimalPointCount elements.
There is a guarantee that the elements of the resulting list cannot be further decomposed:
this method, called for them with the same or larger minimalPointCount argument,
always returns a list consisting of one element.
The number of space dimensions in all returned patterns (Pattern.dimCount() is the same as in this one.
The result of this method is immutable (Collections.unmodifiableList).
Returns a non-empty list of all best or almost best
union decompositions
with equal or similar "quality",
i.e. with the same or almost same summary number of points in all Minkowski decompositions
of all returned patterns.
This method is a useful addition to Pattern.unionDecomposition(int) method for a case,
when there are several union decompositions with similar "quality".
In this case an algorithm, using union decompositions, is able to choose
the best from several variants according additional algorithm-specific criteria.
The number of space dimensions in all returned patterns (Pattern.dimCount() is the same as in this one.
The result of this method and the elements of the result are immutable
(Collections.unmodifiableList).
minimalPointCount - this method usually does not decompose patterns that contain
less than minimalPointCount points.
Returns:
several good variants of decomposition of this pattern to the union of patterns;
the result always contains ≥1 elements,
and all its elements also contain ≥1 elements.
There is a guarantee, that this method does not try to allocate much more memory,
that it is required for storing this pattern itself, and that it
never throws TooManyPointsInPatternError.
For comparison, an attempt to do the same operation via getting all points (Pattern.points() method),
correcting them and forming a new pattern via Patterns.newPattern(java.util.Collection)
will lead to TooManyPointsInPatternError / OutOfMemoryError for some forms of large patterns.
However, TooLargePatternCoordinatesException is impossible in many important cases, when
this pattern is an integer pattern and each coordinate
Xj=shift.coord(j)
of the argument is equal to −xj for some some point
(x0, x1, ..., xn−1)
of this pattern.
In particular, you can use this method for integer patterns without a risk of
TooLargePatternCoordinatesException in the following situations:
Returns the pattern shifted by the argument, that is consisting of points
with the same weights,
generated from points of this instance by adding the argument via IPoint.add(IPoint) method.
Returns the pattern consisting of points, generated from points of this instance
by multiplying on the mult argument via IPoint.multiply(double) method.
If mult is not an integer, the generated real coordinates are rounded to integer values.
If several source points are rounded to the same integer point, the weights
of the resulting points may differ from the weights of the source ones,
but the sum of all weights will be approximately same.
If the all source points are transformed to different points,
their weights are preserved.
Please note: if mult is not an integer,
the algorithm of rounding is not strictly specified!
However, you can be sure that the new pattern will be near from the precise result.
There is a guarantee, that this method does not try to allocate much more memory,
that it is required for storing this pattern itself, and that it
never throws TooManyPointsInPatternError.
For comparison, an attempt to do the same operation via getting all points (Pattern.points() method),
correcting them and forming a new pattern via Patterns.newPattern(java.util.Collection)
will lead to TooManyPointsInPatternError / OutOfMemoryError for some forms of large patterns.
Warning: this method can fail with TooLargePatternCoordinatesException, if some of new points
violate restrictions, described in the comments to this interface,
section "Coordinate restrictions" (for example, due to very large multipliers).
However, such failure is obviously impossible, if all multipliers are
in range -1.0<=multipliers[k]<=1.0.