Shapes and line types for R

Solution

Note that with bitmap output, the filled symbols 15-18 may render without proper anti-aliasing; they can appear jagged, pixelated, and not properly centered, though this varies among platforms. Symbols 19 and 21-25 have an outline around the filled area, and will render with smoothed edges on most platforms. For symbols 21-25 to appear solid, you will also need to specify a fill (bg) color that is the same as the outline color (col); otherwise they will be hollow.

Standard graphics

Use the
pch
option to set the shape, and use
lty
and
lwd
to set the line type and width. The line type can be specified by name or by number.

set.seed(331)# Plot some points with lines# Set up the plotting areapar(mar=c(3,3,2,2))plot(NA, xlim=c(1,4), ylim=c(0,1))# Plot solid circles with solid linespoints(1:4, runif(4), type="b", pch=19)# Add open squares with dashed line, with heavier line widthpoints(1:4, runif(4), type="b", pch=0,  lty=2, lwd=3)points(1:4, runif(4), type="b", pch=23,   # Diamond shape       lty="dotted", cex=2,               # Dotted line, double-size shapes       col="#000099", bg="#FF6666")       # blue line, red fill

ggplot2

With ggplot2, shapes and line types can be assigned overall (e.g., if you want all points to be squares, or all lines to be dashed), or they can be conditioned on a variable.

# Sample datadf <- read.table(header=T, text='  cond xval yval     A    1  2.0     A    2  2.5     B    1  3.0     B    2  2.0')library(ggplot2)# Plot with standard lines and points# group = cond tells it which points to connect with linesggplot(df, aes(x=xval, y=yval, group = cond)) +    geom_line() +    geom_point()# Set overall shapes and line typeggplot(df, aes(x=xval, y=yval, group = cond)) +    geom_line(linetype="dashed",  # Dashed line              size = 1.5) +       # Thicker line    geom_point(shape = 0,         # Hollow squares               size = 4)          # Large points# Condition shapes and line type on variable condggplot(df, aes(x=xval, y=yval, group = cond)) +    geom_line(aes(linetype=cond), # Line type depends on cond              size = 1.5) +       # Thicker line    geom_point(aes(shape=cond),   # Shape depends on cond               size = 4)          # Large points# Same as previous, but also change the specific linetypes and# shapes that are usedggplot(df, aes(x=xval, y=yval, group = cond)) +    geom_line(aes(linetype=cond), # Line type depends on cond              size = 1.5) +       # Thicker line    geom_point(aes(shape=cond),   # Shape depends on cond               size = 4) +        # Large points    scale_shape_manual(values=c(6,5)) +                  # Change shapes    scale_linetype_manual(values=c("dotdash", "dotted")) # Change linetypes

By default, ggplot2 uses solid shapes. If you want to use hollow shapes, without manually declaring each shape, you can use
scale_shape(solid=FALSE)
. Note, however, that the lines will visible inside the shape. To avoid this, you can use shapes 21-25 and specify a white fill.

# Hollow shapesggplot(df, aes(x=xval, y=yval, group = cond)) +    geom_line(aes(linetype=cond), # Line type depends on cond              size = 1.5) +       # Thicker line    geom_point(aes(shape=cond),   # Shape depends on cond               size = 4)  +       # Large points    scale_shape(solid=FALSE)# Shapes with white fillggplot(df, aes(x=xval, y=yval, group = cond)) +    geom_line(aes(linetype=cond), # Line type depends on cond              size = 1.5) +       # Thicker line    geom_point(aes(shape=cond),   # Shape depends on cond               fill = "white",    # White fill               size = 4)  +       # Large points    scale_shape_manual(values=c(21,24))  # Shapes: Filled circle, triangle

Note

This code will generate the chart of line types seen at the top.

par(mar=c(0,0,0,0))# Set up the plotting areaplot(NA, xlim=c(0,1), ylim=c(6.5, -0.5),    xaxt="n", yaxt="n",    xlab=NA, ylab=NA )# Draw the linesfor (i in 0:6) {    points(c(0.25,1), c(i,i), lty=i, lwd=2, type="l")}# Add labelstext(0, 0, "0. 'blank'"   ,  adj=c(0,.5))text(0, 1, "1. 'solid'"   ,  adj=c(0,.5))text(0, 2, "2. 'dashed'"  ,  adj=c(0,.5))text(0, 3, "3. 'dotted'"  ,  adj=c(0,.5))text(0, 4, "4. 'dotdash'" ,  adj=c(0,.5))text(0, 5, "5. 'longdash'",  adj=c(0,.5))text(0, 6, "6. 'twodash'" ,  adj=c(0,.5))