Returns the integer ASCII value of a character argument.

Returns the ASCII value of a character converted to uppercase.

Computes the day of the week for a given date.

Retrieves the code for an informational error.

Checks if a floating‑point number is NaN (not a number).

Compares two character strings using the ASCII collating sequence without regard to case.

Determines the position in a string at which a given character sequence begins without regard to case.

Retrieves integer machine constants.

Performs an includance test.

Computes estimates of the impulse response weights and noise series of a univariate transfer function model.

Searches a sorted integer vector for a given integer and returns its index.