Recalculation

Recalculation ensures that the contents of number slots remain up to date at all times. Every time you make a change to a slot, PipeDream recalculates all other slots which depend upon it.

PipeDream 4 recalculates automatically unless you specify otherwise. With PipeDream 4's advanced recalculation facilities, you should never need to switch to manual recalculation. However, the option to do so exists. You can switch off automatic recalculation by clicking on the Auto recalc option on the Choices sub-menu to turn it off. If you switch to manual recalculation, when you give the Recalculate command, PipeDream will recalculate all those slots which have changed since the last recalculation. Switching recalculation to manual applies to all documents in your computer.

PipeDream uses natural recalculation. This means that when you change a value in the spreadsheet, or enter a new value, instead of recalculating the whole spreadsheet, PipeDream recalculates only those slots which need to be altered as a result of the change you have made. Therefore, only a small section usually needs to be recalculated, and recalculation is completed quickly. Natural recalculation also means that forward references are automatically resolved; if you have forward references, you do not have to give the Recalculate command several times to get the values to stabilise. With natural recalculation, you cannot have circular or self-references. If you put the formula A1+1 in slot A1, PipeDream will display the error Circular reference.

Background Recalculation

PipeDream 4 recalculates in the background, ie when nothing else is going on in the computer. This means that you can get on with something else either in PipeDream or in another program whilst recalculation is going on. PipeDream will carry on recalculating the spreadsheet whenever there is some time to do so. Whilst PipeDream is recalculating, a number is shown in the mark block box at the top left-hand side of the screen. This number represents the number of slots PipeDream knows it has to recalculate. Due to the complexities of natural recalculation, the number may go up during a recalculation if PipeDream finds more slots needing recalculation, but generally it goes down until it reaches zero.

To Recalculate

If you have chosen to use manual recalculation, you will need to gave the Recalculate command to recalculate your spreadsheet:

Menu Command Ctrl-sequence Key
Files Recalculate A

All slots in the document which need recalculating will be recalculated. The hourglass may be displayed while PipeDream completes this operation if there are many slots to recalculate.