Phil Goetz - 4 months ago 30

R Question

On the output of read.table, as.vector produces an m x 1 matrix rather a length m vector:

`# data.txt contains one integer per line and nothing else`

dataframe = read.table("data.txt", encoding='UTF-8', header=F)

v = as.vector(dataframe)

is.vector(v)

[1] FALSE

length(v)

[1] 1

dim(v)

[1] 19783 1

Answer

To summerise the above data types:

- Data frame: A tabular object where each column can be a different type. A data frame is really a list.
- Matrix: A tabular object where all values must have the same type.
- Vector: A one dimensional object; all values must have the same type.

Hence it doesn't (in general) make sense to convert from a data frame to a vector.

In your example, you can either

```
unlist(dataframe)
```

or convert to a matrix, then use `as.vector`

```
as.vector(data.matrix(dataframe))
```