# Extract functional coefficients Obtain the coefficients component from a functional object (functional data, class `fd`, functional parameter, class `fdPar`, a functional smooth, class `fdSmooth`, or a Taylor spline representation, class `Taylor`. ```r ## S3 method for class 'fd' coef(object, ...) ## S3 method for class 'fdPar' coef(object, ...) ## S3 method for class 'fdSmooth' coef(object, ...) ## S3 method for class 'fd' coefficients(object, ...) ## S3 method for class 'fdPar' coefficients(object, ...) ## S3 method for class 'fdSmooth' coefficients(object, ...) ``` ## Arguments - `object`: An object whose functional coefficients are desired - ``...``: other arguments ## Details Functional representations are evaluated by multiplying a basis function matrix times a coefficient vector, matrix or 3-dimensional array. (The basis function matrix contains the basis functions as columns evaluated at the `evalarg` values as rows.) ## Returns A numeric vector or array of the coefficients. ## 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 `coef` `fd` `fdPar` `smooth.basisPar` `smooth.basis` ## Examples ```r ## ## coef.fd ## bspl1.1 <- create.bspline.basis(norder=1, breaks=0:1) fd.bspl1.1 <- fd(0, basisobj=bspl1.1) coef(fd.bspl1.1) ## ## coef.basisPar ## rangeval <- c(-3,3) # set up some standard normal data x <- rnorm(50) # make sure values within the range x[x < -3] <- -2.99 x[x > 3] <- 2.99 # set up basis for W(x) basisobj <- create.bspline.basis(rangeval, 11) # set up initial value for Wfdobj Wfd0 <- fd(matrix(0,11,1), basisobj) WfdParobj <- fdPar(Wfd0) coef(WfdParobj) ## ## coef.fdSmooth ## girlGrowthSm <- with(growth, smooth.basisPar(argvals=age, y=hgtf, lambda=0.1)$fd) coef(girlGrowthSm) ```

coef function