Question

Please solve in R

1. For each part below, give a single R command to accomplish the goal. Do not use the c() function.

a. Create a character vector called halpvec whose elements are the two words “halp me” repeated 36 times (that’s correct - I said “halp” not “help”).

b. Create a 6-row, 6-column matrix called halpmat from the vector halpvec .

c. Write one statement to accomplish parts (a) and (b) of this problem, without saving halpvec. (I have already solved part a & b, but I have no idea about part c )

2. Give a single command that will fix the spelling in the existing vector halpvec, storing the result in a vector called helpvec. Do not use the c()function or the rep()function.  (hint: look first at the help file for the function called grep).

("halpvec" is from the previous question )

Answer 1

c)

You need to use the 'matrix' function to do so. Use the following code -

> halpmat <- matrix("halp me", nrow = 6, ncol = 6)

> halpmat

This would give you following output -

[,1] [,2] [,3] [,4] [,5] [,6]   
[1,] "halp me" "halp me" "halp me" "halp me" "halp me" "halp me"
[2,] "halp me" "halp me" "halp me" "halp me" "halp me" "halp me"
[3,] "halp me" "halp me" "halp me" "halp me" "halp me" "halp me"
[4,] "halp me" "halp me" "halp me" "halp me" "halp me" "halp me"
[5,] "halp me" "halp me" "halp me" "halp me" "halp me" "halp me"
[6,] "halp me" "halp me" "halp me" "halp me" "halp me" "halp me"
-------------------------------------------------------------------------

2)

You create a vector of 36 "halp me" without using c() and rep() using following code -

> halpvec <- character(length = 36)
> halpvec[1:36] <- "halp me"

Then use the 'gsub' function as -

> helpvec <- gsub("halp", "help", halpvec)
> helpvec

This would give following output -

[1] "help me" "help me" "help me" "help me" "help me" "help me" "help me" "help me" "help me" "help me" "help me"
[12] "help me" "help me" "help me" "help me" "help me" "help me" "help me" "help me" "help me" "help me" "help me"
[23] "help me" "help me" "help me" "help me" "help me" "help me" "help me" "help me" "help me" "help me" "help me"
[34] "help me" "help me" "help me"