`distance.Rd`

Computes a multivariate distance (one of: "manhattan", "euclidean", "chi", and "hellinger") between two vectors of the same length. It is used internally by `distanceMatrix`

and `autoSum`

. This function has no buit-in error trapping procedures in order to speed up execution.

distance(x, y, method = "manhattan")

x | numeric vector. |
---|---|

y | numeric vector of the same length as |

method | character string naming a distance metric. Valid entries are: "manhattan", "euclidean", "chi", and "hellinger". Invalid entries will throw an error. |

A number representing the distance between both vectors.

Vectors `x`

and `y`

are not checked to speed-up execution time. Distances are computed as:

`manhattan`

:`d <- sum(abs(x - y))`

`euclidean`

:`d <- sqrt(sum((x - y)^2))`

`chi`

:`xy <- x + y y. <- y / sum(y) x. <- x / sum(x) d <- sqrt(sum(((x. - y.)^2) / (xy / sum(xy))))`

`hellinger`

:`d <- sqrt(1/2 * sum(sqrt(x) - sqrt(y))^2)`

Note that zeroes are replaced by 0.00001 whem `method`

equals "chi" or "hellinger".

#> [1] 32.83516