R: Read data interactively and check that it satisfies...

read.and.check {coda} | R Documentation

## Read data interactively and check that it satisfies conditions

### Description

Input is read interactively and checked against conditions specified by the arguments `what`, `lower`, `upper` and `answer.in`. If the input does not satisfy all the conditions, an appropriate error message is produced and the user is prompted to provide input. This process is repeated until a valid input value is entered.

### Usage

    read.and.check(message = "", what = numeric(), lower, upper, answer.in,
    default)

### Arguments

`message` | message displayed before prompting for user input.
`what` | the type of `what` gives the type of data to be read.
`lower` | lower limit of input, for numeric input only.
`upper` | upper limit of input, for numeric input only.
`answer.in` | the input must correspond to one of the elements of the vector `answer.in`, if supplied.
`default` | value assumed if user enters a blank line.

### Value

The value of the valid input. When the `default` argument is specified, a blank line is accepted as valid input and in this case `read.and.check` returns the value of `default`.

### Note

Since the function does not return a value until it receives valid input, it extensively checks the conditions for consistency before prompting the user for input. Inconsistent conditions will cause an error.

### Author(s)

Martyn Plummer

[Package coda version 0.19-1 Index]