You can add children to decision and event nodes by:
Note that you cannot add children to payoff nodes.
You can insert nodes to the left or right of existing nodes with the following exceptions:
You can insert a node by:
Nodes can be moved up and down in the tree by:
When nodes are removed from the tree their child nodes, if any, become children of their parent node. Note that the root node cannot be deleted.
To remove a node:
To remove a node and its child nodes:
To change the type(s) of the selected node(s):
Any node in the tree can be assigned a label. The label is located above the branch leading to the node. Click on this space to add a node label.
Nodes that are children of event nodes have associated probabilities. The probability field is located beneath the branch leading to the node.
You can use the special "@" character to force probabilities to sum to 1: Nodes with this probability value will evaluate to 1 minus the sum of the probabilities of sibling nodes.
All terminal nodes have associated payoff values, represented by a number to the right of the node. You can enter values directly in the tree or by double-clicking on a payoff node.
Nodes can have more than one payoff value assigned. By default, the tree is solved according to the displayed payoff. You can change the displayed payoff and payoff names through the payoff preferences form .
You can change the formula by which payoffs are evaluated through the analysis preferences form .
You can define distributions that can be used in probability and payoff expressions throughout the tree. To create a new distribution:
Distributions can be sampled by performing a Monte Carlo simulation. Distributions evaluate to their means when performing basic rollback or sensitivity analyses.
You can define variables that can be used in probability and payoff expressions throughout the tree. To create a new variable:
Variables are assigned a base numerical value that is available throughout the tree. Additionally, you can update variable definitions at specific nodes:
There are three saving options available from the save menu :
You can open an existing saved tree in a new window by clicking on the open-tree menu button . This will launch a dialog to select a saved tree to open.
Create a new tree by clicking on the create-tree menu button .
Click on the solve menu button to solve the tree. Click again to hide the solution.
An alert will display if you attempt to solve a poorly formed tree where one or more leaf nodes are not payoff nodes.
Click on the analysis preferences menu button to set preferences for the analysis:
Operator | Example | Description | Returns |
---|---|---|---|
+ | x + y | Addition | The sum of x and y. |
- | x - y | Subtraction | The difference between x and y. |
* | x * y | Multiplication | The product of x and y. |
/ | x / y | Division | The quotient of x and y. Throws an exception if y is 0. |
^ | x ^ y | Exponentiation | x raised to the y power. |
! | ! x | Logical not | 0 if x is greater than 0, else 1. |
&& | x && y | Logical and | 1 if x and y evaluate to greater than 0, else returns 0. |
|| | x || y | Logical or | 1 if x or y evaluates to greater than 0, else returns 0. |
? : | x ? y : z | Ternary | y if x evaluates to greater than 0, else z. |
() | x * (y + z) | Parentheses | Grouping for operator precedence. |
Comparator | Example | Description | Returns |
---|---|---|---|
< | x < y | Less than | 1 if x is less than y, else 0. |
<= | x <= y | Less than or equal | 1 if x is less than or equal to y, else 0. |
> | x > y | Greater than | 1 if x is greater than y, else 0. |
>= | x >= y | Greater than or equal | 1 if x is greater than or equal to y, else 0. |
<> | x <> y | Not equal | 1 if x is not equal to y, else 0. |
!= | x != y | Not equal | 1 if x is not equal to y, else 0. Synonomous with <>. |
Symbol | Description | Precedence |
---|---|---|
-, ! | Unary minus, negation | 8 |
^ | Power | 7 |
* | Multiplication | 6 |
/ | Division | 6 |
+ | Addition | 5 |
- | Subtraction | 5 |
==, >, <, etc. | Comparators | 4 |
&& | Logical and | 3 |
|| | Logical or | 3 |
? | Ternary | 2 |
() | Grouping | 1 |
, | Function argument separator | 1 |
Constant | Description | Evaluates to |
---|---|---|
E | Base of natural logarithm | ~ 2.718 |
FALSE | False | 0 |
LN2 | Natural logarithm of 2 | ~ 0.693 |
LN10 | Natural logarithm of 10 | ~ 2.302 |
PI | Pi | ~ 3.1416 |
SQRT1_2 | Square root of 1/2 | ~ 0.707 |
SQRT2 | Square root of 2 | ~ 1.414 |
TRUE | True | 1 |
Function | Description | Returns |
---|---|---|
abs(x) | Absolute value | The absolute value of x. |
acos(x) | Arccosine | The arccosine of x. Throws exception if x is less than -1 or greater than 1. |
and(x_{0}, x_{1}, ... x_{n}) | And | 1 if all arguments are greater than 0, else 0. |
asin(x) | Arcsine | The arcsine of x. Throws exception is x is less than 0 or greater than 1. |
atan(x) | Arctangent | The arctangent of x. Throws exception is x is less than -1 or greater than 1. |
ceiling(x) | Ceiling | x rounded up to the closest integer. |
choose(x, y_{0}, y_{1}, ... y_{n}) | Choose | y_{i} where i is equal to x. Throws exception if x does not correspond to an element index. |
compound(rate, periods) | Compound | The periodic rate compounded over the specified periods. |
cos(x) | Cosine | The cosine of x. |
discount(amount, rate, periods) | Discount | The present value of amount discounted at a periodic rate over periods. |
exp(x) | Exponent | e raised to x. |
floor(x) | Floor | x rounded down to the nearest integer. |
if(x, y, z) | If | y if x is greater than 0, else z. |
log(x) | Base-10 logarithm | The base-10 logarithm of x. Throws exception if x is less than or equal to 0. |
ln(x) | Natural logarithm | The natural logarithm of x. Throws exception if x is less than or equal to 0. |
max(x_{0}, x_{1}, ... x_{n}) | Maximum | The maximum value among the arguments. |
mean(x_{0}, x_{1}, ... x_{n}) | Mean | The arithmetic mean of the arguments. |
min(x_{0}, x_{1}, ... x_{n}) | Minimum | The minimum value among the arguments. |
mod(x, y) | Modulo | The remainder of dividing x by y. Throws exception if y is 0. |
not(x) | Negation | 0 if x is greater than 0, else returns 1. |
npv(rate, x_{0}, x_{1}, ... x_{n}) | Net present value | The net present value of payments x_{0}...x_{n} discounted by periodic rate. Payments occur at the end of each period. |
oddsToProb(odds) | Odds to probability | The odds as a probability. |
or(x_{0}, x_{1}, ... x_{n}) | Or | 1 if any arguments are greater than 0, else 0. |
pow(x, y) | Power | x raised to the y power. |
probToOdds(prob) | Probability to odds | The probability prob as odds. |
probToRate(prob, periods) | Probability to rate | Probability prob converted to a rate over periods. |
product(x_{0}, x_{1}, ... x_{n}) | Product | The product of x_{0}...x_{n}. |
pv(pmt, final, rate, periods) | Present value | The present value of recurring payment amount pmt over periods discounted by rate. final is a final payment at the end of the last period. |
quotient(x, y) | Quotient | The integer portion as a result of dividing x by y. Throws exception if y equals 0. |
rand() | Random | A pseudo-random number in the range [0,1]. |
randInt(x, y) | Random integer | A pseudo-random integer in the range [x, y]. |
rangeRange(x, y) | Random range | A pseudo-random number in the range [x, y]. |
rateToProb(rate, periods) | Rate to probability | The rate over periods as a probability. |
round(x) | Round | x rounded to the nearest integer. |
sin(x) | Sine | The sine of x. |
sqrt(x) | Square root | The square root of x. |
sum(x_{0}, x_{1}, ... x_{n}) | Sum | The sum of x_{0}...x_{n}. |
tan(x) | Tangent | The tangent of x. |
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