1d:T7ba,# Values of Basis Functions or their Derivatives Evaluate a set of basis functions or their derivatives at a set of argument values. ```r getbasismatrix(evalarg, basisobj, nderiv=0, returnMatrix=FALSE) ``` ## Arguments - `evalarg`: a vector of arguments values. - `basisobj`: a basis object. - `nderiv`: a nonnegative integer specifying the derivative to be evaluated. - `returnMatrix`: logical: If TRUE, a two-dimensional is returned using a special class from the Matrix package. ## Returns a matrix of basis function or derivative values. Rows correspond to argument values and columns to basis functions. ## References Ramsay, James O., Hooker, Giles, and Graves, Spencer (2009), **Functional data analysis with R and Matlab**, Springer, New York. Ramsay, James O., and Silverman, Bernard W. (2005), **Functional Data Analysis, 2nd ed.**, Springer, New York. Ramsay, James O., and Silverman, Bernard W. (2002), **Applied Functional Data Analysis**, Springer, New York. ## See Also `eval.fd` ## Examples ```r ## ## Minimal example: a B-spline of order 1, i.e., a step function ## with 0 interior knots: ## bspl1.1 <- create.bspline.basis(norder=1, breaks=0:1) m <- getbasismatrix(seq(0, 1, .2), bspl1.1) # check m. <- matrix(rep(1, 6), 6, dimnames=list(NULL, 'bspl') ) all.equal(m, m.) ## ## Date and POSIXct ## # Date July4.1776 <- as.Date('1776-07-04') Apr30.1789 <- as.Date('1789-04-30') AmRev <- c(July4.1776, Apr30.1789) BspRevolution <- create.bspline.basis(AmRev) AmRevYears <- as.numeric(seq(July4.1776, Apr30.1789, length.out=14)) AmRevMatrix <- getbasismatrix(AmRevYears, BspRevolution) matplot(AmRevYears, AmRevMatrix, type='b') # POSIXct AmRev.ct <- as.POSIXct1970(c('1776-07-04', '1789-04-30')) BspRev.ct <- create.bspline.basis(AmRev.ct) AmRevYrs.ct <- as.numeric(seq(AmRev.ct[1], AmRev.ct[2], length.out=14)) AmRevMat.ct <- getbasismatrix(AmRevYrs.ct, BspRev.ct) matplot(AmRevYrs.ct, AmRevMat.ct, type='b') ```

getbasismatrix function