Evaluate Spline Basis Functions at Specified Points

This function evaluates the given spline basis functions at the specified x.

Usage

# S3 method for bSpline2
predict(object, newx, ...)

# S3 method for dbs
predict(object, newx, ...)

# S3 method for ibs
predict(object, newx, ...)

# S3 method for mSpline
predict(object, newx, ...)

# S3 method for iSpline
predict(object, newx, ...)

# S3 method for cSpline
predict(object, newx, ...)

# S3 method for bernsteinPoly
predict(object, newx, ...)

# S3 method for naturalSpline
predict(object, newx, ...)

Arguments

object: Objects of class bSpline2, ibs, mSpline, iSpline, cSpline, bernsteinPoly or naturalSpline with attributes describing knots, degree, etc.
newx: The x values at which evaluations are required.
...: Optional arguments that are not used.

Value

An object just like the object input, except evaluated at the new values of x.

Details

These are methods for the generic function predict for objects inheriting from class bSpline2, ibs, mSpline, iSpline, cSpline, naturalSpline, or bernsteinPoly. If newx is not given, the function returns the input object.

Examples

library(splines2)
x <- seq.int(0, 1, 0.2)
knots <- c(0.3, 0.5, 0.6)
newX <- seq.int(0.1, 0.9, 0.2)

## for B-splines
bsMat <- bSpline(x, knots = knots, degree = 2)
predict(bsMat, newX)
#>              1          2            3      4      5
#> [1,] 0.4888889 0.06666667 0.000000e+00 0.0000 0.0000
#> [2,] 0.4000000 0.60000000 5.135813e-32 0.0000 0.0000
#> [3,] 0.0000000 0.33333333 6.666667e-01 0.0000 0.0000
#> [4,] 0.0000000 0.00000000 4.500000e-01 0.4875 0.0625
#> [5,] 0.0000000 0.00000000 5.000000e-02 0.3875 0.5625

## for integral of B-splines
ibsMat <- ibs(x, knots = knots, degree = 2)
predict(ibsMat, newX)
#>               1           2            3          4           5
#> [1,] 0.02740741 0.002222222 0.000000e+00 0.00000000 0.000000000
#> [2,] 0.14000000 0.060000000 9.503163e-49 0.00000000 0.000000000
#> [3,] 0.16666667 0.188888889 4.444444e-02 0.00000000 0.000000000
#> [4,] 0.16666667 0.200000000 1.883333e-01 0.04291667 0.002083333
#> [5,] 0.16666667 0.200000000 2.316667e-01 0.14541667 0.056250000

## for derivative of B-splines
dbsMat <- dbs(x, knots = knots, degree = 2)
predict(dbsMat, newX)
#>              1         2             3     4    5
#> [1,]  3.111111  1.333333  0.000000e+00  0.00 0.00
#> [2,] -4.000000  4.000000  1.850372e-15  0.00 0.00
#> [3,]  0.000000 -6.666667  6.666667e+00  0.00 0.00
#> [4,]  0.000000  0.000000 -3.000000e+00  1.75 1.25
#> [5,]  0.000000  0.000000 -1.000000e+00 -2.75 3.75

## for M-spline
msMat <- mSpline(x, knots = knots, degree = 2)
predict(msMat, newX)
#>             1         2            3     4       5
#> [1,] 2.933333 0.3333333 0.000000e+00 0.000 0.00000
#> [2,] 2.400000 3.0000000 2.201063e-31 0.000 0.00000
#> [3,] 0.000000 1.6666667 2.857143e+00 0.000 0.00000
#> [4,] 0.000000 0.0000000 1.928571e+00 2.925 0.46875
#> [5,] 0.000000 0.0000000 2.142857e-01 2.325 4.21875

## for I-spline
isMat <- iSpline(x, knots = knots, degree = 2)
predict(isMat, newX)
#>              1         2          3            4      5        6
#> [1,] 0.7037037 0.1644444 0.01111111 0.000000e+00 0.0000 0.000000
#> [2,] 1.0000000 0.8400000 0.30000000 4.072784e-48 0.0000 0.000000
#> [3,] 1.0000000 1.0000000 0.94444444 1.904762e-01 0.0000 0.000000
#> [4,] 1.0000000 1.0000000 1.00000000 8.071429e-01 0.2575 0.015625
#> [5,] 1.0000000 1.0000000 1.00000000 9.928571e-01 0.8725 0.421875

## for C-spline
csMat <- cSpline(x, knots = knots, degree = 2)
predict(csMat, newX)
#>               1           2            3            4          5          6
#> [1,] 0.04304304 0.007222222 0.0004273504 0.000000e+00 0.00000000 0.00000000
#> [2,] 0.24324324 0.135000000 0.0346153846 1.413031e-64 0.00000000 0.00000000
#> [3,] 0.45945946 0.375000000 0.2329059829 2.380952e-02 0.00000000 0.00000000
#> [4,] 0.67567568 0.625000000 0.5384615385 2.861607e-01 0.06416667 0.00390625
#> [5,] 0.89189189 0.875000000 0.8461538462 7.504464e-01 0.57527778 0.31640625