Accumulate

Format: x -> y

Arguments: (real) x Any real value to add to the global accumulator

[any] y Any valid expression

Returns: [any] y or value of the global accumulator

Description: This operator is used exclusively for building expected value decision trees. It allows you to enter incremental value or cost numbers in tree nodes and then calculate the total accumulated cost in end nodes.

The operator works by first evaluating x and adding its value to a global accumulator variable. It then evaluates y, resets the accumulator to its original value, and then returns the value of y. Other nodes referenced in y will most likely use the Accumulate operator as well and add more to the accumulator variable. In end nodes, the expression for y is omitted to cause the Accumulate operator to return the value in the accumulator variable.

Examples: Try:=-100->emv(50%,Succeed,50%,Fail) = Create a branch node

Succeed:=150-> = Create an end node

Fail:=0-> = Create an end node

Try = -25

Succeed = 50 (-100+150)

Fail = -100 (-100+0)

See Also: emv, max