Vectors
If you are selecting a vector element and you type in x[4], which element(s) are you selecting?
The 4th element
View the entire data frame
what does a == b mean?
a and b are equal
when is the select() function used?
when choosing a column (to include or exclude)
If you are selecting a vector element and you type in x[-4], which element(s) are you selecting?
All but the 4th element
What does head(df) mean?
View the first 6 rows of the data frame
what does a != b mean?
a and b are not equal
when is the filter() function used?
when choosing a row to include or exclude
If you are selecting a vector element and you type in x[2:6], which element(s) are you selecting?
Elements 2 to 6
What do cbind & rbind mean?
These are used to combine the columns/rows of two data sets into one data frame
what is round(x, n)?
round to n decimal places
If you are selecting a vector element and you type in x[x > 5], which element(s) are you selecting?
All elements greater than 5
What do the following functions tell you?
nrow(df), ncol(df), dim(df)
nrow(df) tells you the amount of rows in the df
ncol(df) tells you the amount of columns in the df
dim(df) tells you the amount of rows and columns
what does is.null(a) tell us?
Indicates when a data object or data type is null (no value associated with it)
what is signif(x, n)?
round to n significant figures
If you are selecting a vector element and you type in x['blue'], which element(s) are you selecting?
Element with the name blue
What is the dplyr package used for
data manipulation
what is the readr package used for?
to read files
what does the following function mean?
if (i < 6){
print ('Yes')
} else {
print ('No')
}
If I is less than 6, output will show as yes. Otherwise, output will show as no