CodeMirror

# Code from http://www.mayin.org/ajayshah/KB/R/

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# FIRST LEARN ABOUT LISTS --

X = list(height=5.4, weight=54)

print("Use default printing --")

print(X)

print("Accessing individual elements --")

cat("Your height is ", X$height, " and your weight is ", X$weight, "\n")

​

# FUNCTIONS --

square <- function(x) {

  return(x*x)

}

cat("The square of 3 is ", square(3), "\n")

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                 # default value of the arg is set to 5.

cube <- function(x=5) {

  return(x*x*x);

}

cat("Calling cube with 2 : ", cube(2), "\n")    # will give 2^3

cat("Calling cube        : ", cube(), "\n")     # will default to 5^3.

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# LEARN ABOUT FUNCTIONS THAT RETURN MULTIPLE OBJECTS --

powers <- function(x) {

  parcel = list(x2=x*x, x3=x*x*x, x4=x*x*x*x);

  return(parcel);

}

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X = powers(3);

print("Showing powers of 3 --"); print(X);

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# WRITING THIS COMPACTLY (4 lines instead of 7)

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powerful <- function(x) {

  return(list(x2=x*x, x3=x*x*x, x4=x*x*x*x));

}

print("Showing powers of 3 --"); print(powerful(3));

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# In R, the last expression in a function is, by default, what is

# returned. So you could equally just say:

powerful <- function(x) {list(x2=x*x, x3=x*x*x, x4=x*x*x*x)}

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