The numericSequence class extends the positionsNumeric class.

Valid numericSequence objects must contain a single non-NA number in at least three of the four slots. If all four are present, the length slot is ignored, and a warning message is generated when the sequence is used.

If length is present and not ignored, it must be non-negative. (A zero-length sequence is equivalent to numeric(0).) Otherwise, the sign of the by slot must agree with the sign of (to - from) to have a valid sequence. In particular, if by is zero, then to and from must be equal. The default sequence (generated by calling numericSequence() or new("numericSequence")) has length 0.

A numericSequence can be coerced to numeric or integer using as, and regularly-spaced numbers can be coerced to numericSequence using as. This fails if the input is not a regular arithmetic sequence within a tolerance given by timeDateOptions("ts.eps").

Most operations on numericSequence objects (for example, mathematical functions, arithmetic, comparison operators, or subscripting) work by first coercing to a numeric vector, and therefore do not return numericSequence objects.