R: fields - graphics hints

fields.hints {fields} | R Documentation

## fields - graphics hints

### Description

Here are some technical hints for assembling multiple plots with common legends or axes and setting the graphics parameters to make more readable figures. Also we an index to the defaultcolors in R graphics and setting their definitions in LaTeX. All these hints use the standard graphics environment.

### Usage

    fields.style()
    fields.color.picker()

### Details

`fields.style` is a simple function to enlarge the characters in a plot and set the colors. List this out to modify the choices.

    ##Two examples of concentrating a panel of plots together
    ## to conserve the white space.
    ## see also the example in image.plot using split.screen.
    ## The basic trick is to use the oma option to reserve some space around the
    ## plots.  Then unset the outer margins to use that room.

    library( fields)

    # some hokey image data
    x<- 1:20
    y<- 1:15
    z<-  outer( x,y,"+")
    zr<- range( c(z))

    # add common legend to 3X2 panel

    par( oma=c(4,0,0,0))
    set.panel( 3,2)
    par( mar=c(1,1,0,0))

    # squish plots together with just 1 space between
    for ( k in 1:6){
    image( x,y,z, axes=FALSE, xlab="", ylab="", zlim=zr)
    }

    par( oma=c(0,0,0,0))
    image.plot( zlim=zr, legend.only=TRUE, horizontal=TRUE, legend.mar=5)

    # you may have to play around with legend.mar and the oma settings to
    # get enough space.

    ##
    ### also add some axes on the sides. in a lattice style
    ## note oma adds some more room at bottom.

    par( oma=c(8,6,1,1))
    set.panel( 3,2)
    par( mar=c(1,1,0,0))
    ##
    for ( k in 1:6){
     image( x,y,z, axes=FALSE, xlab="", ylab="", zlim=zr)
     box() # box around figure

    # maybe draw an x axis
      if( k  %in% c(5,6) ){
      axis( 1, cex.axis=1.5)
      mtext( line=4, side=1, "Xstuff")}

    # maybe draw a y axis
      if( k  %in% c(1,3,5) ){
      axis( 2, cex.axis=1.5)
      mtext( line=4, side=2, "Ystuff")}
    }

    # same trick of adding a legend strip.
    par( oma=c(0,0,0,0))
    image.plot( zlim=zr, legend.only=TRUE, horizontal=TRUE, legend.mar=5)

    # reset panel
    set.panel()

    ####
    # show colors
    ## the factory colors:

    clab<- colors()
    n<- length( clab)
    N<- ceiling( sqrt(n) )
    M<- N
    temp<- rep( NA,M*N)
    temp[1:n] <- 1:n
    z<- matrix(temp, M,N)

    image(seq(.5,M+.5,,M+1), seq(.5,N+.5,,N+1)
           , z,  col=clab, axes=FALSE, xlab="", ylab="")

    # see the  function  fields.color.picker() to locate colors

    # dumping out colors by name for a latex document
    # this creates text strings that are the LaTeX color definitions
    # using the definecolor function.

    # grab all of the R default colors
    clab<- colors()

    for( nn in clab){
      temp<- signif(col2rgb(nn)/256, 3)
       cat(
        "\definecolor{",
                    nn, "}",
        "{rgb}{", temp[1],
              ",", temp[2],
              ",", temp[3],
               "}", fill=TRUE , sep="")
     }

    # this loop prints out definitions such as
    # \definecolor{yellowgreen}{rgb}{0.602,0.801,0.195}
    # having loaded the color package in LaTeX
    # defining this color
    # use the construction  {\color{yellowgreen}  THIS IS A COLOR}
    # to use this color in a talk or document.

    # this loop prints out all the colors in LaTeX language
    # as their names and can be converted to a pdf for handy reference.

    sink( "showcolors.tex")

    clab<- colors()
    for( nn in clab){
      temp<- signif(col2rgb(nn)/256, 3)
       cat(
        "\definecolor{",
                    nn, "}",
        "{rgb}{", temp[1],
              ",", temp[2],
              ",", temp[3],
               "}", fill=TRUE , sep="")
       cat( paste("{ \color{",nn,"} ", nn," $\bullet$ \\ }", sep=""),
                        fill=TRUE)
    }
    sink()

[Package fields version 9.6.1 Index]