# marginal: Marginal Distributions In prob: Elementary Probability on Finite Sample Spaces

## Description

Computes the marginal distribution of a set of variables.

## Usage

 `1` ```marginal(space, vars = NULL) ```

## Arguments

 `space` a data frame probability space or a subset of one. `vars` an optional character vector of variable names in `space`.

## Details

If `vars` is not specified, then `marginal()` will set `vars` to be all non-`probs` columns, which can be useful in the case that it is desired to aggregate duplicated rows.

## Value

A data frame with a `probs` column.

## Author(s)

G. Jay Kerns gkerns@ysu.edu.

See `addrv` for adding random variables to a data frame probability space.

## Examples

 ```1 2``` ```S <- rolldie(3, makespace = TRUE) marginal(S, vars = c("X1", "X2")) ```

### Example output

```Loading required package: combinat

Attaching package: ‘combinat’

The following object is masked from ‘package:utils’:

combn

Attaching package: ‘prob’

The following objects are masked from ‘package:base’:

intersect, setdiff, union

X1 X2      probs
1   1  1 0.02777778
2   2  1 0.02777778
3   3  1 0.02777778
4   4  1 0.02777778
5   5  1 0.02777778
6   6  1 0.02777778
7   1  2 0.02777778
8   2  2 0.02777778
9   3  2 0.02777778
10  4  2 0.02777778
11  5  2 0.02777778
12  6  2 0.02777778
13  1  3 0.02777778
14  2  3 0.02777778
15  3  3 0.02777778
16  4  3 0.02777778
17  5  3 0.02777778
18  6  3 0.02777778
19  1  4 0.02777778
20  2  4 0.02777778
21  3  4 0.02777778
22  4  4 0.02777778
23  5  4 0.02777778
24  6  4 0.02777778
25  1  5 0.02777778
26  2  5 0.02777778
27  3  5 0.02777778
28  4  5 0.02777778
29  5  5 0.02777778
30  6  5 0.02777778
31  1  6 0.02777778
32  2  6 0.02777778
33  3  6 0.02777778
34  4  6 0.02777778
35  5  6 0.02777778
36  6  6 0.02777778
```

prob documentation built on May 2, 2019, 12:20 p.m.