0th

Percentile

##### Read data interactively and check that it satisfies conditions

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.

Keywords
utilities
##### 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.
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.