The following table lists valid parameter values for each Crystal Ball distribution. Distributions are listed alphabetically by type (continuous or discrete). The Oracle Crystal Ball Reference and Examples Guide lists defaults for each parameter value.
Table 11. Distributions and Their Parameters
Distribution |
| Type | Parameter 1 | Parameter 2 | Parameter 3 | Parameter 4 |
---|---|---|---|---|---|---|
Beta | continuous | alpha (greater than 0.3, alpha + beta must be less than 1e5) | beta (greater than 0.3, alpha + beta must be less than 1e5) | maximum value | minimum value | |
BetaPERT | continuous | minimum value | likeliest value | maximum value | N/A | |
Exponential | continuous | rate (greater than 0) | N/A | N/A | N/A | |
Gamma | continuous | location | scale (greater than 0) | shape (greater than 0.05 and less than 1e6) | N/A | |
Logistic | continuous | mean value | scale (greater than 0) | N/A | N/A | |
Lognormal | continuous | location | mean value | standard deviation value | N/A | |
Maximum extreme | continuous | likeliest | scale (greater than 0) | N/A | N/A | |
Minimum extreme | continuous | likeliest | scale (greater than 0) | N/A | N/A | |
Normal | continuous | mean value | standard deviation value | N/A | N/A | |
Pareto | continuous | location (greater than 0) | shape (greater than 0.05, less than 1e6) | N/A | N/A | |
Student’s t | continuous | midpoint | scale (greater than 0) | degrees of freedom (integer between 1 and 30, inclusive) | N/A | |
Triangular | continuous | minimum value | likeliest value | maximum value | N/A | |
Uniform | continuous | minimum value | maximum value | N/A | N/A | |
Weibull | continuous | location | scale (greater than 0) | shape (greater than 0.05, less than 1e6) | N/A | |
Binomial | discrete | probability (between 0 and 1) | trials (a whole number greater than 0 and less than 1e9) | N/A | N/A | |
Discrete Uniform | discrete | minimum (integer) | maximum (integer) | N/A | N/A | |
Geometric | discrete | probability (between 0 and 1) | N/A | N/A | N/A | |
Hyper- geometric | discrete | success | trials (whole number less than population) | population (whole number greater than 0 and less than 1e5) | N/A | |
Negative binomial | discrete | probability (between 0 and 1) | shape (whole number greater than 0 and less than 1e6) | N/A | N/A | |
Poisson | discrete | rate value (between 0 and 1e9) | N/A | N/A | N/A | |
Yes-No | discrete | probability (between 0 and 1) | N/A | N/A | N/A | |
Custom | custom | See Appendix A of the current Oracle Crystal Ball User's Guide. | N/A | N/A | N/A |