9.1.1 Environments
# Package Environments and Namespaces
ls("package:graphics")## [1] "abline" "arrows" "assocplot"
## [4] "axis" "Axis" "axis.Date"
## [7] "axis.POSIXct" "axTicks" "barplot"
## [10] "barplot.default" "box" "boxplot"
## [13] "boxplot.default" "boxplot.matrix" "bxp"
## [16] "cdplot" "clip" "close.screen"
## [19] "co.intervals" "contour" "contour.default"
## [22] "coplot" "curve" "dotchart"
## [25] "erase.screen" "filled.contour" "fourfoldplot"
## [28] "frame" "grconvertX" "grconvertY"
## [31] "grid" "hist" "hist.default"
## [34] "identify" "image" "image.default"
## [37] "layout" "layout.show" "lcm"
## [40] "legend" "lines" "lines.default"
## [43] "locator" "matlines" "matplot"
## [46] "matpoints" "mosaicplot" "mtext"
## [49] "pairs" "pairs.default" "panel.smooth"
## [52] "par" "persp" "pie"
## [55] "plot" "plot.default" "plot.design"
## [58] "plot.function" "plot.new" "plot.window"
## [61] "plot.xy" "points" "points.default"
## [64] "polygon" "polypath" "rasterImage"
## [67] "rect" "rug" "screen"
## [70] "segments" "smoothScatter" "spineplot"
## [73] "split.screen" "stars" "stem"
## [76] "strheight" "stripchart" "strwidth"
## [79] "sunflowerplot" "symbols" "text"
## [82] "text.default" "title" "xinch"
## [85] "xspline" "xyinch" "yinch"9.1.2 Search Path
# Viewing R's search path
search()## [1] ".GlobalEnv" "package:stats" "package:graphics"
## [4] "package:grDevices" "package:utils" "package:datasets"
## [7] "package:methods" "Autoloads" "package:base"# Enclosing environment
environment(seq)## <environment: namespace:base># Updated package found via search()
library(car)## Loading required package: carDatasearch()## [1] ".GlobalEnv" "package:car" "package:carData"
## [4] "package:stats" "package:graphics" "package:grDevices"
## [7] "package:utils" "package:datasets" "package:methods"
## [10] "Autoloads" "package:base"# List all objects in global environment
ls()## character(0)# Remove all objects in global environment
rm()Exercise 9.1
# a.
ls("package:methods")[1:20]## [1] "addNextMethod" "allGenerics"
## [3] "allNames" "Arith"
## [5] "as" "as<-"
## [7] "asMethodDefinition" "assignClassDef"
## [9] "assignMethodsMetaData" "balanceMethodsList"
## [11] "body<-" "cacheGenericsMetaData"
## [13] "cacheMetaData" "cacheMethod"
## [15] "callGeneric" "callNextMethod"
## [17] "canCoerce" "cbind2"
## [19] "checkAtAssignment" "checkSlotAssignment"# a.
length(ls("package:methods"))## [1] 218# b i.
environment(read.table)## <environment: namespace:utils># b ii.
environment(data)## <environment: namespace:utils># b iii.
environment(matrix)## <environment: namespace:base># b iv.
environment(jpeg)## <environment: namespace:grDevices>any(ls("package:graphics")=="smoothScatter")## [1] TRUE9.2.5 Dot-Dot-Dot: Use of Ellipses
# Functions with unknown number of args.
args(data.frame)## function (..., row.names = NULL, check.rows = FALSE, check.names = TRUE,
## fix.empty.names = TRUE, stringsAsFactors = default.stringsAsFactors())
## NULLExercise 9.2
# a.
seq(-4,4, 0.2)## [1] -4.0 -3.8 -3.6 -3.4 -3.2 -3.0 -2.8 -2.6 -2.4 -2.2 -2.0 -1.8 -1.6 -1.4
## [15] -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
## [29] 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0# b i.
array(8:1, dim=c(2,2,2))## , , 1
##
## [,1] [,2]
## [1,] 8 6
## [2,] 7 5
##
## , , 2
##
## [,1] [,2]
## [1,] 4 2
## [2,] 3 1# Mixed data positional and dim exact.# b ii.
rep(1:2,3)## [1] 1 2 1 2 1 2# positional# b iii.
seq(from = 10, to = 8, length = 5)## [1] 10.0 9.5 9.0 8.5 8.0# mixed from and to exact and length.out partialsort(decreasing = T, x = c(2,1,1,2,0.3,3,1.3))## [1] 3.0 2.0 2.0 1.3 1.0 1.0 0.3# Exact# b iv.
which(matrix(c(T,F,T,T),2,2)) ## [1] 1 3 4# Positional# b vi.
which(matrix(c(T,F,T,T),2,2),a=T) ## row col
## [1,] 1 1
## [2,] 1 2
## [3,] 2 2# Mixed: 'x', 'data', 'nrow', 'ncol' positional, 'arr.ind' partial#(c)
# 'pch', 'lwd', 'lty' and 'col' are part of the ellipsis.