Loop over Variables in a Data Frame or Environment

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Description

Foreach evaluates an expression given as second argument by substituting in variables. The expression may also contain assignments, which take effect in the callers environment.

Usage

1

Arguments

...

tagged and untagged arguments. The tagged arguments define the 'variables' that are looped over, the first untagged argument defines the expression wich is evaluated.

Examples

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x <- 1:3
y <- -(1:3)
z <- c("Uri","Schwyz","Unterwalden")
print(x)
print(y)
print(z)
Foreach(var=c(x,y,z),          # assigns names
  names(var) <- letters[1:3]   # to the elements of x, y, and z
  )
print(x)
print(y)
print(z)