Halcyon Calc
Halcyon Calc Lite
Poll
What feature do you want in Halcyon Calc v4.1
Stats plotting
15%
Implement the FORM operation
31%
Built-in catalog of operations
8%
Built-in catalog of units
8%
Printing support
0%
iCloud support for user variables
23%
Other (add a comment)
15%
Total votes: 13
FACT
Argument Types:
Real
Symbol
Expression
Result Type(s):
Real
Expression
Invertible:
No
Valid In Expression:
Yes
Stack Diagram:
| Real1 | → | Real2 |
| Symbol1 | → | Expression2 |
| Expression1 | → | Expression2 |
This function returns the factorial of its input parameter. For integer input values greater than or equal to 0, that means that x! is returned where x is the input value. However, FACT returns a value for all real values between -1 and 170, including non-integer values. It does so using the Gamma function. Assuming that the input value is x, the result then is Γ(x+1). For all other values, an infinite result error is returned.