in formula command the factorial ! calculation not done .
is there is function to get factorial values and combination values
We do not have built-in functions for calculating factorial nor for combination values. But you can write your own functions for that. I prepared a small example:
Example:
F(4) = {=factorial(4)}
C(4, 2) = {=combination(4, 2)}
{factorial=(n)->reduce(seq(1,n), 1, (a, v)->a*v)}
{combination=(n, r)->factorial(n)/factorial(r)/factorial(n-r)}
Here how it works:
- Lambda functions are used to create custom functions. You can read more about them here.
-
seq(1,n)
- this is built-in function that creates an ordered list from 1 ton
. -
reduce
- this is also built-in function that aggregates the elements of the list. It starts with1
which is the second parameter, uses list that was generated byseq
function and applies aggregation function which is a third parameter. In general it just multiplies all the elements ofseq
.
You can find all the available built-in functions here.
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Small update, the factorial function was not working for 0
. Here an updated formula to fix that bug:
{factorial=(n)->reduce(seq(1,n), 1, (a, v)->a*v) if n > 0 else 1}