drawExpression: Draw a graphical representation of the evaluation of an R...
In drawExpression: Visualising R syntax through graphics

Description Usage Arguments Value Author(s) Examples

Draw a graphical representation of the steps of the evaluation of an R expression. Each line in the graphic represent a step in the resolution of the expression. Following the syntax tree, each function is resolved starting with the inner most. Common R object (vector, matrix, list) and mode (numeric, character, logical) are distinguished thanks graphical conventions. This representation is intented to represent the abstract syntax for pedagogical purposes.

1	drawExpression(expr, draw.index = FALSE, draw.names = FALSE, filename = NULL)

`expr`	An R expression to be drawn; must not contain affectation.
`draw.index`	Should index (for R objects such as vector, matrix or list) be drawn on the margin of graphics?
`draw.names`	Should names (if any) be drawn on the margin of graphics?
`filename`	The name of a PDF file where the plot will be saved

None.

Sylvain Loiseau <sloiseau@u-paris10.fr>

  drawExpression("1:4");
  drawExpression("matrix(1:4, 2)");
  drawExpression("list(1:4, matrix(1:4, 2), 2, 3, 4)");
  drawExpression("c(1, 2, 3:5) > 2");

  x <- 1:4
  drawExpression("x");
  drawExpression("sum(x)");