R Language 6th day 128 page __r language

1 adding a single data to a vector

> v <-C (v,newitems)

It can also be set to the next element of the vector v[length (v) +1] <-NewItem

2 is very slow with append.

3 When you add a lot of data to a vector

With append function > Append (VEC, NewValues, After=n)

4 1:6 1:3 (1:6) + (1:3)

1 1 2

2 2 4

3 3 6

4 1 5

5 2 7

6 3 9

5 Creating a column vector with the Cbind function

6 Creating a factor

Using the Factor function

> F <-Factor (V,levels) # V is a vector of strings or integers

> F <-Factor (Wday, C ("Mon", "Tue", "Wed", "Thu", "Fri"))

7 combining multiple vectors with a stack function to synthesize a dataframe

> Comb <-Stack (list (V1=V1, V2=v2, V3=v3)) # Combine 3 vectors

8 Build a list

The list can contain different data types