All Functions of Week 10

nobs

{gdata}

Compute the number of non-missing observations

sample_frac

{dplyr}

Sample a fraction of observations from a data frame

pchisq

{stats}

Gives the distribution function of the chi-squared distribution

select

{dplyr}

Select columns from a tibble/data frame

vif

{car}

Calculate Variance Inflation Factor

names

{base}

Retrieve names of a list/vector

vcovHC

{sandwich}

Heteroscedasticity-consistent estimation of the covariance matrix of the coefficient estimates

ls

{base}

Return a vector of character strings giving the names of the objects in the specified environment

summary

{base}

Obtain summary statistics or detailed regression output

filter

{dplyr}

Filter out rows of a data frame according to logical vector

leveneTest

{car}

Computes Levene’s test for homogeneity of variance across groups.

library

{base}

Load an R package

c

{base}

Combine values/vectors into a vector

read.csv

{utils}

Read a csv file to data frame. Specify stringsAsFactors = FALSE to keep all string columns as characters

mutate

{dplyr}

Modify/create a column in a data frame

set.seed

{base}

Initialise a pseudorandom number generator.

lm

{base}

Fit a linear model

bptest

{lmtest}

Breusch-Pagan Test for Homoscedasticity

rm

{base}

Remove objects

coeftest

{lmtest}

Inference for Estimated Coefficients

cut

{base}

Convert Numeric to Factor

attach

{base}

Attach Set of R Objects to Search Path

t.test

{stats}

Performs one and two sample t-tests on vectors of data.

setwd

{base}

Set Working Directory

resid

{stats}

Extracts model residuals from objects returned by modeling functions

The end!