`R/lookup.R`

`vlookup.Rd`

This is a simple wrapper to the `match`

function.

vlookup(x, data, key, value, nomatch = NA)

x | Vector of items to lookup in key-value pairs. |
---|---|

data | Dataframe containing key-value columns. |

key | Vector of keys that are searched. |

value | Vector of values to be returned. |

nomatch | The value to be returned in the case when no match is found. Note that it is coerced to integer. |

A vector the same length as `x`

, but containing the values
of `value`

. If `x[i]`

is equal to `key[j]`

, then the
value returned in the ith position of the vector is `value[j]`

.
If no match is found, `NA`

is returned.

Search for elements of `x`

in dataframe `data`

,
column `key`

, and return the corresponding element of column
`value`

.
If no match is found, return `nomatch`

.

Kevin Wright

# Example 1. A and B have different factor levels A <- factor(c("A","E","F")) dat <- data.frame(trt = factor(c("E","F","G")), val = c(4,2,0)) vlookup(A,dat, "trt", "val")#> [1] NA 4 2