Posts in 'R'

Mathematical expressions in plots

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Mathematical expressions can be included in the plot title or axis labels. For more information, see ?plotmath or run the demo with demo(plotmath).

Here are some quick examples.

Example 1

plot(0, 0, main = expression(theta == 0), ylab = expression(hat(gamma) == 0), 
    xlab = expression(sum ...

Plotting with Lattice

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The lattice library is useful for quickly making plots of multivariate data. It's easy to make plots which condition on one or more variables.

Load the lattice library


# Ask for general information about the lattice package
`?`(package, lattice)

# See what is inside of ...


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mapply gives us a way to call a non-vectorized function in a vectorized way.

From the R Documentation:

mapply is a multivariate version of sapply. mapply applies FUN to
the first elements of each ... argument, the second elements,
the third elements, and so on. Arguments are ...

R Base Graphics Plotting

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Important parameters

  • pch: plotting symbol
  • lty: line type
  • lwd: line width
  • col: plotting color
  • las: orientation of axis labels
  • bg: background color
  • mar: margin size
  • oma: outer margin size
  • mfrow: number of plots per row, column. Plots filled in row-wise.
  • mfcol: number of plots per row ...

tapply and split

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Apply a function over subsets of a vector.

Example: Take group means with tapply.

x <- c(rnorm(10), runif(10), rnorm(10, 1))
##  [1] -2.04333  0.72651  1.55476 -0.12411  1.08133 -0.30514  1.38638
##  [8]  0.35047  0.88147  1 ...