class B_Spline extends BasisFunction with Error
The B_Spline
class provides B-Spline basis functions for various orders 'm',
where the order is one more than the degree. A spline function is a piecewise
polynomial function where the pieces are stitched together at knots with the
goal of maintaining continuity and differentiability. B-Spline basis functions
form a popular form of basis functions used in Functional Data Analysis.
- See also
http://web.mit.edu/hyperbook/Patrikalakis-Maekawa-Cho/node17.html -----------------------------------------------------------------------------
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Instance Constructors
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new
B_Spline(ττ: VectoD, mMax: Int = 4, clamp: Boolean = true)
- ττ
the time-points of the original knots in the time dimension
- mMax
the maximum order, allowing splines orders from 1 to mMax
- clamp
flag for augmenting ττ
Value Members
-
final
def
!=(arg0: Any): Boolean
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final
def
##(): Int
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final
def
==(arg0: Any): Boolean
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val
DEBUG: Boolean
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-
def
abf(m: Int)(t: VectoD): MatrixD
Obtain the value of the m-th order basis functions (all) at time 't'.
Obtain the value of the m-th order basis functions (all) at time 't'. Or alternatively, obtain the basis function by calling bf(m)(j) only. Ex: val x = bf(m)(t) retrieves the value of all the basis functions at 't'. val f = bf(m) retrieves all the basis functions.
- m
the order of all the basis function
- t
the time parameter
- Definition Classes
- BasisFunction
-
def
abf_(m: Int = mMax)(t: Double): VectorD
Evaluate each of the
τ.dim-1
-many orderm
B-spline basis functions att
non-recursively, using an efficient dynamic programming approach.Evaluate each of the
τ.dim-1
-many orderm
B-spline basis functions att
non-recursively, using an efficient dynamic programming approach.Example
val m = 4 // order m (degree m-1) val t = VectorD (1, 2, 3, 4) // original time points val N = B_Spline (t, k) // B_Spline instance val z = N.abf_ (m)(t) // vector of evaluations println ("order k basis functions at t = z")
Implementation Details
Let
N(m)(i)
denote thei
-th orderk
basis function evaluated att
. Then eachN(m)(i)
depends on the evaluation ofN(m-1)(i)
andN(m-1)(i+1)
. Here is an example, given a set of orderm=4
B-spline basis functions and knot vectorτ
of lengthn
:N(1)(0), N(1)(1), N(1)(2), N(1)(3), ..., N(1)(n-1) |/ |/ |/ |/ N(2)(0), N(2)(1), N(2)(2), ..., N(2)(n-2) |/ |/ |/ N(3)(0), N(3)(1), ..., N(3)(n-3) |/ |/ N(4)(0), ..., N(4)(n-4)
This algorithm applies the procedure described above using O(n) storage and O(k*n) floating point operations.
- m
the order of all the basis function
- t
point to evaluate
- Definition Classes
- B_Spline → BasisFunction
- See also
Carl de Boor (1978). A Practical Guide to Splines. Springer-Verlag. ISBN 3-540-90356-9.
-
def
apply(m: Int)(j: Int)(t: Double): Double
Obtain the value of the m-th order 'j'-th basis function at time 't'.
Obtain the value of the m-th order 'j'-th basis function at time 't'. Or alternatively, obtain the basis function by calling bf(m)(j) only. Ex: val x = bf(m)(j)(t) retrieves the value of the j-th basis function at 't'. val f = bf(m)(j) retrieves the j-th basis function.
- m
the order of the basis function
- j
indicates which basis function
- t
the time parameter
- Definition Classes
- BasisFunction
-
final
def
asInstanceOf[T0]: T0
- Definition Classes
- Any
-
def
bb(m: Int)(j: Int)(t: Double): Double
Order 'm' B-Spline basis functions (general recurrence).
Order 'm' B-Spline basis functions (general recurrence).
- m
the order of the spline function (degree = order - 1)
- j
indicates which spline function
- t
the time parameter
-
def
bf(m: Int)(j: Int)(t: Double): Double
Evaluate the 'j+1'-th order
m
B-spline basis function att
non-recursively, using an efficient dynamic programming approach.Evaluate the 'j+1'-th order
m
B-spline basis function att
non-recursively, using an efficient dynamic programming approach.Example
val m = 4 // order m (degree m-1) val t = VectorD (1, 2, 3, 4) // original time points val N = B_Spline (t, k) // B_Spline instance val j = 0 // spline j in N.range(m) val z = N.bf (m)(j)(t(2)) // evaluate at t(2) println ("order k basis function j at t(2) = z")
Implementation Details
Let
N(m)(i)
denote thei
-th orderk
basis function evaluated att
. Then eachN(m)(i)
depends on the evaluation ofN(m-1)(i)
andN(m-1)(i+1)
. Here is an example, given a set of orderm=4
B-spline basis functions and knot vectorτ
of lengthn
:N(1)(0), N(1)(1), N(1)(2), N(1)(3) |/ |/ |/ N(2)(0), N(2)(1), N(2)(2) |/ |/ N(3)(0), N(3)(1) |/ N(4)(0)
This algorithm applies the procedure described above using O(k) storage and O(k*k) floating point operations.
- m
the order of the basis function
- j
indicates which basis function
- t
point to evaluate
- Definition Classes
- B_Spline → BasisFunction
- See also
Carl de Boor (1978). A Practical Guide to Splines. Springer-Verlag. ISBN 3-540-90356-9.
-
def
bf1(j: Int)(t: Double): Double
Obtain the value of the 1st order 'j'-th basis function at time 't'.
Obtain the value of the 1st order 'j'-th basis function at time 't'. Or alternatively, obtain the basis function by calling bf1(j) only. Ex: val x = bf1(j)(t) retrieves the value of the j-th basis function at 't'. val f = bf1(j) retrieves the j-th basis function.
- j
indicates which basis function
- t
the time parameter
- Definition Classes
- BasisFunction
-
def
bf2(j: Int)(t: Double): Double
Obtain the value of the 2nd order 'j'-th basis function at time 't'.
Obtain the value of the 2nd order 'j'-th basis function at time 't'. Or alternatively, obtain the basis function by calling bf2(j) only. Ex: val x = bf2(j)(t) retrieves the value of the j-th basis function at 't'. val f = bf2(j) retrieves the j-th basis function.
- j
indicates which basis function
- t
the time parameter
- Definition Classes
- BasisFunction
-
def
bf3(j: Int)(t: Double): Double
Obtain the value of the 3rd order 'j'-th basis function at time 't'.
Obtain the value of the 3rd order 'j'-th basis function at time 't'. Or alternatively, obtain the basis function by calling bf3(j) only. Ex: val x = bf3(j)(t) retrieves the value of the j-th basis function at 't'. val f = bf3(j) retrieves the j-th basis function.
- j
indicates which basis function
- t
the time parameter
- Definition Classes
- BasisFunction
-
def
bf4(j: Int)(t: Double): Double
Obtain the value of the 4th order 'j'-th basis function at time 't'.
Obtain the value of the 4th order 'j'-th basis function at time 't'. Or alternatively, obtain the basis function by calling bf4(j) only. Ex: val x = bf4(j)(t) retrieves the value of the j-th basis function at 't'. val f = bf4(j) retrieves the j-th basis function.
- j
indicates which basis function
- t
the time parameter
- Definition Classes
- BasisFunction
-
def
bfr(m: Int)(j: Int)(t: Double): Double
Adjusted order 'm' B-Spline basis functions (general recurrence).
Adjusted order 'm' B-Spline basis functions (general recurrence). These are adjusted so that the first "usable" spline is at
j = 0
. The valid range of usable splines is defined inrange
.- m
the order of the spline function (degree = order - 1)
- j
indicates which spline function
- t
the time parameter
-
def
clone(): AnyRef
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def
count(m: Int): Int
The number of basis functions for a specified order.
The number of basis functions for a specified order.
- m
the order of the basis function
- Definition Classes
- BasisFunction
-
def
dot_(m: Int)(i: Int, j: Int)(g: BasisFunction, a: Double = 0.0, b: Double = 1.0): Double
Compute the dot/inner product of 'this' basis function object and basis function 'g'.
Compute the dot/inner product of 'this' basis function object and basis function 'g'.
- m
the order of the basis function
- i
indicates which basis function of 'this'
- j
indicates which basis function of 'g'
- g
the other function
- a
the start of the interval
- b
the end of the interval
- Definition Classes
- BasisFunction
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final
def
eq(arg0: AnyRef): Boolean
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def
equals(arg0: Any): Boolean
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def
finalize(): Unit
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final
def
flaw(method: String, message: String): Unit
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def
getCache(m: Int, t: VectoD): Array[MatrixD]
Retrieves the cached design matrices
Retrieves the cached design matrices
- Definition Classes
- BasisFunction
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final
def
getClass(): Class[_]
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def
getOrder: Int
Retrieve the order of the this B_Spline.
Retrieve the order of the this B_Spline.
- Definition Classes
- B_Spline → BasisFunction
-
def
hashCode(): Int
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val
head: Double
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final
def
isInstanceOf[T0]: Boolean
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val
l: Int
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final
def
ne(arg0: AnyRef): Boolean
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val
needCompute: Boolean
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final
def
notify(): Unit
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final
def
notifyAll(): Unit
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def
range(m: Int = mMax): Inclusive
Range of "usable" splines when using the
bs
function.Range of "usable" splines when using the
bs
function. This is needed, since extra splines may be generated by the general B-spline recurrence.- m
the order of the spline
- Definition Classes
- B_Spline → BasisFunction
-
def
recomputeCache: Unit
Recompute cached matrices
Recompute cached matrices
- Definition Classes
- BasisFunction
-
def
size(m: Int = mMax): Int
The number of usable spline basis functions for a specified order, given the configured knot vector.
The number of usable spline basis functions for a specified order, given the configured knot vector.
- m
the order of the spline
- Definition Classes
- B_Spline → BasisFunction
-
final
def
synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
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val
tail: Double
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def
toString(): String
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final
def
wait(): Unit
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final
def
wait(arg0: Long, arg1: Int): Unit
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final
def
wait(arg0: Long): Unit
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val
Φ: MatrixD
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val
Φt: MatrixD
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val
ΦtΦ: MatrixD
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val
τ: VectoD
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- protected