# Embed a new plot within an existing plot Subplot will embed a new plot within an existing plot at the coordinates specified (in user units of the existing plot). ```r subplot(fun, x, y, size=c(1,1), vadj=0.5, hadj=0.5, inset=c(0,0), type=c('plt','fig'), pars=NULL) ``` ## Arguments - `fun`: an expression defining the new plot to be embedded. - `x`: `x`-coordinate(s) of the new plot (in user coordinates of the existing plot), or a character string. - `y`: `y`-coordinate(s) of the new plot, `x` and `y` can be specified in any of the ways understood by `xy.coords`. - `size`: The size of the embedded plot in inches if `x` and `y` have length 1. - `vadj`: vertical adjustment of the plot when `y` is a scalar, the default is to center vertically, 0 means place the bottom of the plot at `y`, 1 places the top of the plot at `y`. - `hadj`: horizontal adjustment of the plot when `x` is a scalar, the default is to center horizontally, 0 means place the left edge of the plot at `x`, and 1 means place the right edge of the plot at `x`. - `inset`: 1 or 2 numbers representing the proportion of the plot to inset the subplot from edges when x is a character string. The first element is the horizontal inset, the second is the vertical inset. - `type`: Character string, if 'plt' then the plotting region is defined by `x`, `y`, and `size` with axes, etc. outside that box; if 'fig' then all annotations are also inside the box. - `pars`: a list of parameters to be passed to `par` before running `fun`. ## Details The coordinates `x` and `y` can be scalars or vectors of length 2. If vectors of length 2 then they determine the opposite corners of the rectangle for the embedded plot (and the parameters `size`, `vadj`, and `hadj` are all ignored). If `x` and `y` are given as scalars then the plot position relative to the point and the size of the plot will be determined by the arguments `size`, `vadj`, and `hadj`. The default is to center a 1 inch by 1 inch plot at `x,y`. Setting `vadj` and `hadj` to `(0,0)` will position the lower left corner of the plot at `(x,y)`. If `x` is a character string, then it will be parsed for the strings "left", "right", "top", and "bottom" and x and y will be set appropriately (anything not specified will be set at the center in that dimension) using also the `inset` argument. This allows the position of the subplot to be specified as 'topleft' or 'bottom', etc. The `inset` argument is in proportion of the plot units, so 0.1 means inset 10% of the width/height of the plotting distance. If `hadj`/`vadj` are not specified, they will be set appropriately. The rectangle defined by `x`, `y`, `size`, `vadj`, and `hadj` will be used as the plotting area of the new plot. Any tick marks, axis labels, main and sub titles will be outside of this rectangle if `type` is 'plt'. If type is 'fig' then the annotations will be inside the box. Any graphical parameter settings that you would like to be in place before `fun` is evaluated can be specified in the `pars` argument (warning: specifying layout parameters here (`plt`, `mfrow`, etc.) may cause unexpected results). After the function completes the graphical parameters will have been reset to what they were before calling the function (so you can continue to augment the original plot). ## Returns An invisible list with the graphical parameters that were in effect when the subplot was created. Passing this list to `par` will enable you to augment the embedded plot. ## Author(s) Greg Snow 538280@gmail.com ## See Also `grconvertX`, `par`, `symbols`, `my.symbols`, `ms.image` ## Examples ```r # make an original plot plot( 11:20, sample(51:60) ) # add some histograms subplot( hist(rnorm(100)), 15, 55) subplot( hist(runif(100),main='',xlab='',ylab=''), 11, 51, hadj=0, vadj=0) subplot( hist(rexp(100, 1/3)), 20, 60, hadj=1, vadj=1, size=c(0.5,2) ) subplot( hist(rt(100,3)), c(12,16), c(57,59), pars=list(lwd=3,ask=FALSE) ) ### some of the following examples work fine in an interactive session, ### but loading the packages required does not work well in testing. # augment a map if( interactive() && require(spData) ){ plot(state.vbm,fg=NULL) tmp <- cbind( state.vbm$center_x, state.vbm$center_y ) for( i in 1:50 ){ tmp2 <- as.matrix(USArrests[i,c(1,4)]) tmp3 <- max(USArrests[,c(1,4)]) subplot( barplot(tmp2, ylim=c(0,tmp3),names=c('',''),yaxt='n'), x=tmp[i,1], y=tmp[i,2], size=c(.1,.1)) } } tmp <- rnorm(25) qqnorm(tmp) qqline(tmp) tmp2 <- subplot( hist(tmp,xlab='',ylab='',main=''), grconvertX(0.1,from='npc'), grconvertY(0.9,from='npc'), vadj=1, hadj=0 ) abline(v=0, col='red') # wrong way to add a reference line to histogram # right way to add a reference line to histogram op <- par(no.readonly=TRUE) par(tmp2) abline(v=0, col='green') par(op) # scatter-plot using images if(interactive() && require(png)) { image.png <- function(x,...) { cols <- rgb( x[,,1], x[,,2], x[,,3], x[,,4] ) z <- 1:length(cols) dim(z) <- dim(x[,,1]) z <- t(z) z <- z[ ,rev(seq_len(ncol(z))) ] image(z, col=cols, axes=FALSE, ...) } logo <- readPNG(system.file("img", "Rlogo.png", package="png")) x <- runif(10) y <- runif(10) plot(x,y, type='n') for(i in 1:10) { subplot(image.png(logo), x[i], y[i], size=c(0.3,0.3)) } } ```

subplot function