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Message-ID: <0cc0e20b-3fe5-5b56-0002-b4159ce9a4d1@gmail.com>
Date: 2018-05-26T00:31:22Z
From: Duncan Murdoch
Subject: [R-pkg-devel] Errors in R package - Updated
In-Reply-To: <CAGVr+e8ScECVqUY1wa67rYV5B-CjQ_LWocO1toCzU738ycpHmg@mail.gmail.com>

On 25/05/2018 3:25 PM, Steven Spiriti wrote:
>   To Whom It May Concern:
> 
>      I have created a package called "freeknotsplines" in R, and I need to
> make a few updates to it.  I resubmitted the package, and received the
> following error message:

The problem is that you are mixing up S3 and S4 stuff.  You have an S4 
class "freekt", but you are defining functions like coef.freekt and 
expecting them to act as methods for that class.  That's not how to 
define methods in S4.  You use the methods::setMethod() function to do 
that.  Using the naming convention generic.class() is the way to do it 
in S3.

Since your S4 class has no "coef" methods, you'll get the old S3 generic 
handling your coef(xy.freekt) call, and it doesn't know what to do with 
it.  It will pass the object to stats:::coef.default, which tries to 
extract the coefficients using object$coefficients, and that fails when 
object is xy.freekt.

Duncan Murdoch

> 
> checking examples ... ERROR
> Running examples in ?freeknotsplines-Ex.R? failed
> The error most likely occurred in:
> 
>> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
>> ### Name: coef.freekt
>> ### Title: Compute Coefficients of B-Splines For Free-Knot Splines
>> ### Aliases: coef.freekt
>> ### Keywords: nonparametric regression smooth
>>
>> ### ** Examples
>>
>> x <- 0:30/30
>> truey <- x*sin(10*x)
>> set.seed(10556)
>> y <- truey + rnorm(31, 0, 0.2)
>> xy.freekt <- freelsgen(x, y, degree = 2, numknot = 2, 555)
>> coef(xy.freekt)
> Error: $ operator not defined for this S4 class
> Execution halted
> 
>       This error occurs in one of the examples in the documentation.   It is
> platform dependent, and does not occur on the machine I am using to create
> the package.  freekt is a new class, which is apparently an S4 class.
> 
> Here is the R code for my package:
> 
> #' @export coef freekt
> #' @export fitted freekt
> #' @export residuals freekt
> #' @export plot freekt
> #' @export summary freekt
> #' @export AIC freekt
> #' @export AICc freekt
> #' @export BIC freekt
> #' @export adjGCV freekt
> #' @export adjAIC freekt
> 
> library(splines)
> 
> setClass("freekt", slots = c(x = "numeric", y = "numeric", degree =
> "integer",
>      seed = "integer", stream = "integer", lambda = "numeric",
>      optknot = "numeric", tracehat = "numeric", GCV = "numeric",
>      GSJS = "numeric", call = "call"))
> 
> freelsgen <- function(x, y, degree, numknot, seed = 5, stream = 0)
> {
>    n <- length(x)
>    ord <- degree + 1
>    optknot <- rep(0, times = numknot)
>    tracehat <- 0
>    GCV <- 0
>    GSJS <- 0
>    result <- .C("freelsgen", as.integer(n), as.double(x), as.double(y),
>                 as.integer(ord), as.integer(numknot), as.integer(seed),
>                 as.integer(stream), as.double(optknot),
>                 as.double(tracehat), as.double(GCV), as.double(GSJS))
>    answer <- new("freekt", x = x, y = y, degree = as.integer(degree),
>                  seed = as.integer(seed), stream = as.integer(stream),
>                  lambda = 0, optknot = result[[8]],
>                  tracehat = result[[9]], GCV = result[[10]],
>                  GSJS = result[[11]], call = match.call())
>    return(answer)
> }
> 
> freelsgold <- function(x, y, degree, numknot, seed = 5, stream = 0)
> {
>    n <- length(x)
>    ord <- degree + 1
>    optknot <- rep(0, times = numknot)
>    tracehat <- 0
>    GCV <- 0
>    GSJS <- 0
>    result <- .C("freelsgold", as.integer(n), as.double(x), as.double(y),
>                 as.integer(ord), as.integer(numknot), as.integer(seed),
>                 as.integer(stream), as.double(optknot),
>                 as.double(tracehat), as.double(GCV), as.double(GSJS))
>    answer <- new("freekt", x = x, y = y, degree = as.integer(degree),
>                  seed = as.integer(seed), stream = as.integer(stream),
>                  lambda = 0, optknot = result[[8]],
>                  tracehat = result[[9]], GCV = result[[10]],
>                  GSJS = result[[11]], call = match.call())
>    return(answer)
> }
> 
> freepsgen <- function(x, y, degree, numknot, seed = 5, stream = 0)
> {
>    n <- length(x)
>    ord <- degree + 1
>    optknot <- rep(0, times = numknot)
>    lambda <- 0
>    tracehat <- 0
>    GCV <- 0
>    GSJS <- 0
>    result <- .C("freepsgen", as.integer(n), as.double(x), as.double(y),
>                 as.integer(ord), as.integer(numknot), as.integer(seed),
>                 as.integer(stream), as.double(lambda),
>                 as.double(optknot), as.double(tracehat),
>                 as.double(GCV), as.double(GSJS))
>    answer <- new("freekt", x = x, y = y, degree = as.integer(degree),
>                 seed = as.integer(seed), stream = as.integer(stream),
>                 lambda = result[[8]], optknot = result[[9]],
>                 tracehat = result[[10]], GCV = result[[11]],
>                 GSJS = result[[12]], call = match.call())
>    return(answer)
> }
> 
> freepsgold <- function(x, y, degree, numknot, seed = 5, stream = 0)
> {
>    n <- length(x)
>    ord <- degree + 1
>    optknot <- rep(0, times = numknot)
>    lambda <- 0
>    tracehat <- 0
>    GCV <- 0
>    GSJS <- 0
>    result <- .C("freepsgold", as.integer(n), as.double(x), as.double(y),
>                 as.integer(ord), as.integer(numknot), as.integer(seed),
>                 as.integer(stream), as.double(lambda),
>                 as.double(optknot), as.double(tracehat),
>                 as.double(GCV), as.double(GSJS))
>    answer <- new("freekt", x = x, y = y,  degree = as.integer(degree),
>                 seed = as.integer(seed), stream = as.integer(stream),
>                 lambda = result[[8]], optknot = result[[9]],
>                 tracehat = result[[10]], GCV = result[[11]],
>                 GSJS = result[[12]], call = match.call())
>    return(answer)
> }
> 
> chgbasismat <- function(knot, ord)
> {
>    dimmat <- length(knot) - ord
>    answer <- matrix(0, nrow = dimmat, ncol = dimmat)
>    for (j in 0:(ord-1))
>    {
>        brow <- splineDesign(knot, knot[1], ord, j)
>        brow <- as.vector(brow/factorial(j))
>        answer[j + 1, ] <- brow
>    }
>    nknot <- sort(-1*knot)
>    for (j in 1:(dimmat - ord))
>    {
>        brow <- splineDesign(knot, knot[ord + j], ord, ord - 1)
>        brow2 <- splineDesign(nknot, nknot[length(knot) - ord - (j - 1)],
>                 ord, ord - 1)
>        brow2 <- brow2[dimmat:1]
>        brow <- brow + (-1)^ord * brow2
>        brow <- as.vector(brow/factorial(ord - 1))
>        answer[ord + j, ] <- brow
>    }
>    return(answer)
> }
> 
> coef.freekt <- function(object, ...)
> {
>    xdat <- object at x
>    ydat <- object at y
>    optknot <- object at optknot
>    ord <- object at degree + 1
>    lambda <- object at lambda
>    fulloptknot <- c(rep(min(xdat), ord), optknot, rep(max(xdat), ord))  #
> includes endpoints
>    Xmat <- splineDesign(fulloptknot, xdat, ord)
>    if ((lambda == 0) | (length(optknot) == 0))
>      coef <- solve(t(Xmat)%*%Xmat, t(Xmat)%*%ydat)
>    else
>      {
>        numknots <- length(optknot)
>        Amat <- chgbasismat(fulloptknot, ord)
>        Istar <- diag(c(rep(0, times = ord), rep(1, times = numknots)))
>        coef <- solve(t(Xmat)%*%Xmat + lambda*t(Amat)%*%Istar%*%Amat,
>                      t(Xmat)%*%ydat)
>      }
>    return(coef)
> }
> 
> fitted.freekt <- function(object, xfit = object at x, ...)
> {
>    xdat <- object at x
>    ydat <- object at y
>    optknot <- object at optknot
>    ord <- object at degree + 1
>    fulloptknot <- c(rep(min(xdat), ord), optknot, rep(max(xdat), ord))  #
> includes endpoints
>    coef <- coef.freekt(object)
>    yfit <- splineDesign(fulloptknot, xfit, ord) %*%coef
>    return(yfit)
> }
> 
> residuals.freekt <- function(object, ...)
> {
>    fit <- fitted.freekt(object)
>    return(object at y - fit)
> }
> 
> plot.freekt <- function(x, xfit = x at x, linecolor="blue", lwd = 1, lty = 1,
> ...)
> {
>    xfit <- as.vector(xfit)
>    yfit <- fitted.freekt(x, xfit)
>    plot(x at x, x at y, ...)
>    lines(xfit[order(xfit)], yfit[order(xfit)], col=linecolor,
>          lwd = lwd, lty = lty)
> }
> 
> summary.freekt <- function(object, ...)
> {
>    answer <- NULL
>    if (object at lambda != 0)
>    {
>       currline <- c(object at lambda,
>          rep(NA, times = length(object at optknot)-1))
>       answer <- rbind(answer, currline)
>    }
>    currline <- object at optknot
>    answer <- rbind(answer, currline)
>    currline <- c(object at GCV,
>          rep(NA, times = length(object at optknot)-1))
>    answer <- rbind(answer, currline)
>    RSS <- sum((residuals(object))^2)
>    currline <- c(RSS, rep(NA, times = length(object at optknot)-1))
>    answer <- rbind(answer, currline)
>    if (object at lambda != 0)
>         rownames(answer) <-
>             c("Optimal lambda", "Optimal knots", "GCV", "RSS")
>    else
>         rownames(answer) <- c("Optimal knots", "GCV", "RSS")
>    colnames(answer) <- rep("", times = length(object at optknot))
>    class(answer) <- "table"
>    print(answer)
> }
> 
> AIC.freekt <- function(object, ..., k = 2)
> {
>    answer <- 0
>    RSS <- sum((residuals(object))^2)
>    n <- length(object at x)
>    npar <- object at tracehat
>    answer <- n * log(RSS/n) + k * npar
>    return(answer)
> }
> 
> AICc.freekt <- function(object)
> {
>    answer <- 0
>    RSS <- sum((residuals(object))^2)
>    n <- length(object at x)
>    npar <- object at tracehat
>    answer <- n * log(RSS/n) + 2 * npar +
>              2 * npar * (npar + 1) /(n - npar - 1)
>    return(answer)
> }
> 
> BIC.freekt <- function(object, ...)
> {
>    answer <- 0
>    RSS <- sum((residuals(object))^2)
>    n <- length(object at x)
>    npar <- object at tracehat
>    answer <- n * log(RSS/n) + log(n) * npar
>    return(answer)
> }
> 
> adjGCV.freekt <- function(object, d = 3)
> {
>    RSS <- sum((residuals(object))^2)
>    n <- length(object at x)
>    adjtrace <- object at tracehat + d * length(object at optknot)
>    answer <- (RSS/n) / (1 - adjtrace / n)^2
>    return(answer)
> }
> 
> adjAIC.freekt <- function(object)
> {
>    answer <- 0
>    RSS <- sum((residuals(object))^2)
>    n <- length(object at x)
>    npar <- object at tracehat
>    effdim <- 2 * npar - object at degree - 1
>    answer <- n * log(RSS/n) +  2 * effdim
>    return(answer)
> }
> 
> fit.search.numknots <- function(x, y, degree, minknot = 1, maxknot = 5,
>                                  alg = "LS", search = "genetic",
>                                  knotnumcrit = "adjGCV", k = 2,
>                                  d = 3, seed = 5, stream = 0)
> {
>    bestcrit <- Inf
>    funcname <- ""
>    answer <- NULL
>    if ((alg == "LS") && (search == "genetic"))
>      funcname <- "freelsgen"
>    if ((alg == "LS") && (search == "golden"))
>      funcname <- "freelsgold"
>    if ((alg == "PS") && (search == "genetic"))
>      funcname <- "freepsgen"
>    if ((alg == "PS") && (search == "golden"))
>      funcname <- "freepsgold"
>    for (numknot in seq(from = minknot, to = maxknot))
>    {
>        currcall <- call(funcname, x, y, degree, numknot, seed, stream)
>        currfit <- eval(currcall)
>        currcrit <- switch(knotnumcrit, GCV = currfit at GCV,
>            AIC = AIC(currfit, k = k), adjAIC = adjAIC.freekt(currfit),
>            AICc = AICc.freekt(currfit), BIC = BIC(currfit),
>            adjGCV = adjGCV.freekt(currfit, d))
>        print(paste("Number of knots = ", numknot, ", ", knotnumcrit,
>            " = ", currcrit, sep = ""), quote = FALSE)
>        if (currcrit < bestcrit)
>        {
>            bestcrit <- currcrit
>            answer <- currfit
>        }
>    }
>    return(answer)
> }
> 
>       I am still not clear on what is causing this error.
> 
> Sincerely,
> 
> Steven Spiriti
> 
> 	[[alternative HTML version deleted]]
> 
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