Is there a command for vector sum in User RPL?

[HP67]

(05-27-2014 06:08 PM)Thomas Klemm Wrote:  

(05-22-2014 01:32 PM)HP67 Wrote:  A vector sum is a fairly basic operation that is useful without having to think too hard.

What would that be? I can come up with normalization of weights to make sure that their sum is 1. But looking at vectors as mathematical objects I don't see a lot of applications.

That's because you're a mathematician and I'm a programmer I was looking at it as a programming object. And I did have a real problem I was working on.

The first thing that comes to mind is to be able to calculate various forms of averages and standard deviations on discrete data without being forced into the built-in stats mode. I had just such a problem I was trying to solve when this issue came up.

But really I look at this as a basic operation that should be part of a language. APL, LISP etc. have this capability. Mathematical functions can operate on vectors.

There are thousands of functions built in to the 50g like f0gamma. So why not vector sum without having to go through an expensive conversion to list or creating a like-sized vector to do a dot product with?

As I found, lists are more storage efficient and have more command support. So I don't see the need for vectors any more until I need to do something that's not supported for lists but is supported for vectors.