A generalisation of the MAP lambda helper function
Discussion topic. Your thoughts are welcome.
On Saturday I finally bit the bullet and completed a MAPλ Lambda function that generalises the in-built MAP Lambda helper function. As examples, I tried problems of generating the Kronecker product of two matrices and then one of generating variants of an amortisation table.
The original amortisation schedule uses SCAN to calculate closing balances step by step from opening balances. Having returned the closing balances as an array, the principal is inserted at the first element to give opening balances. An array calculation based on the same code is used to return other values of interest using HSTACK.
Following that, I created the array of loan terms {10, 15, 20} (yrs) and used the formula
= MAPλ(variousTerms, AmortisationTableλ(principal, rate, startYear))
to generate
as a single spilt range.
I have posted a copy of MAPλ on GitHub
A version of Excel MAP helper function that will return an array of arrays (github.com)
The intention is that the function can be used without knowing how it works but you are, of course, welcome to try to pick through it.
Discussion topic. Your thoughts are welcome. On Saturday I finally bit the bullet and completed a MAPλ Lambda function that generalises the in-built MAP Lambda helper function. As examples, I tried problems of generating the Kronecker product of two matrices and then one of generating variants of an amortisation table. The original amortisation schedule uses SCAN to calculate closing balances step by step from opening balances. Having returned the closing balances as an array, the principal is inserted at the first element to give opening balances. An array calculation based on the same code is used to return other values of interest using HSTACK.Following that, I created the array of loan terms {10, 15, 20} (yrs) and used the formula = MAPλ(variousTerms, AmortisationTableλ(principal, rate, startYear)) to generateas a single spilt range. I have posted a copy of MAPλ on GitHub A version of Excel MAP helper function that will return an array of arrays (github.com)The intention is that the function can be used without knowing how it works but you are, of course, welcome to try to pick through it. Read More
