What Is a Slot?


A slit or narrow opening, especially one for receiving something, as coins or a letter. Also: a position in a group, series, sequence, or hierarchy; an assignment or job opening.

In gaming, a slot is a mechanism for dispensing credits or tokens according to preset rules and regulations. Slots can be found on many different casino machines, from traditional land-based ones to online versions. To play a slot machine, players insert cash or, in the case of “ticket-in, ticket-out” machines, a paper ticket with barcodes into the designated slots on the machine. Then, they activate the machine by pressing a lever or button (physical or virtual on a touchscreen). After the reels stop spinning and the symbols match up, the player receives the credits that correspond to the winning combination.

There are several different kinds of slot, and each type is configured to handle a different kind of data. Periodic slots hold data that repeats at a specific time interval, such as a set of monthly evaporation coefficients for a reservoir. They can have either text or numeric column headers and may have a fixed or variable timeseries associated with them. Periodic slots can also be configured to interpolate or look up, depending on how they are configured.

Scalar slots, on the other hand, store a single piece of numeric data that does not vary with time. They are configured to use a user-defined arithmetic expression that can include values from other slots as variables. A scalar slot can also be configured to compress repeated values, which will reduce the size of the internal data.

A scalar slot can be configured to use any unit, including a non-standard unit. However, any value that shows NaN will be displayed as a non-standard number. For this reason, it is important to always use the Configure Slot dialog to set the Units for a scalar slot.

Regardless of how they are configured, periodic slots are accessed in RPL using standard table syntax: Slot[DateTime>,E] or Slot[DateTime>]E]. A periodic slot that has been configured to interpolate will treat references to dates that fall between columns as if it were interpolating; a periodic slot that is configured to lookup will treat them as if it were looking up. For this reason, it is important to know which kind of slot a particular data set is in before accessing it with RPL. For example, if you reference a period slot that is configured to lookup, but the input data does not have any periods in it, you will get an error message. To avoid this error, you must configure the slot to interpolate before attempting to access it with RPL.