Question

What is the Rcode and result in Rstudio

3. What is the difference between a vector and a list in R? What about the difference between a matrix and a dataframe in R? Without using R, provide the output from the following command in R: 16; d = array(c, dim = c(2,4, 2))an,2, 5. Explain the connection between z and y, where = qnorm(5); y = pnorm (0

Answer 1

Vectors (one-dimensional array): can hold numeric, character or logical values. The elements in a vector all have the same data type.

A list in R allows you to gather a variety of objects under one name in an ordered way. These objects can be matrices, vectors, data frames, even other lists, etc.

It is not even required that these objects are related to each other in any way.

You could say that a list is some kind of super data type: you can store practically any piece of information in it.

4:

c=1:16;d=array(c,dim = c(2,4,2));d[1,2,2]

These are actually three steps

c=1:16

Here you are generating numbers from 1 to 16.

d=array(c,dim = c(2,4,2))

Now you are creating an array of these 16 numbers with 2 matrices of dimensions (4,2) that is 4 columns and two rows.

> d
, , 1

[,1] [,2] [,3] [,4]
[1,] 1 3 5 7
[2,] 2 4 6 8

, , 2

[,1] [,2] [,3] [,4]
[1,] 9 11 13 15
[2,] 10 12 14 16

In the third step d[1,2,2], you are calling the element from the second matrix in the second column and first row.

5)

They are both inverses of each other.

The function pnorm returns the integral from −∞ to q of the pdf of the normal distribution where q is a Z-score.

The qnorm function is simply the inverse of the CDF, which you can also think of as the inverse of pnorm!