Need a little help with DB math

[Botsareus]

Is there a command  (call it “unpow”) that does the vb equivalent of “a ^ (1/b)”?

For example:

64
3
unpow

puts 4 on top of the stack

[Botsareus]

Yep, never mind, the answer is "NO". ( I just realised I have been trough this before)

If we really want to get going with this stuff we might as well add a command (call it “depow”) that does the vb equivalent of “Log(a) / Log(b)"

For example:

64
4
depow

puts 3 on top of the stack

[Shasta]

What you could do is use an approximation of log, wouldn't exactly be nice and clean however  

Also for your first one do you really need a single operator for that?

Code: [Select]

64 1 3 div powThis works just fine.

[Numsgil]

Really?  I guess it was a change Eric made.  Back in the day 1 3 div 3 mult would have been 0 from integer rounding errors.

[Shasta]

Really?  I guess it was a change Eric made.  Back in the day 1 3 div 3 mult would have been 0 from integer rounding errors.

Oh... actually no, its returns 1 (which makes sense if there are rounding errors). I was under several assumptions, including that it would work because the math works  sorry

[Numsgil]

I remember Eric talked about it once, so it wouldn't have surprised me.  Mostly I objected to the idea, because floating point is a whole can of worms with how it works.

[Botsareus]

That is why I suggest we skip the floating point bull and do the calculations internally:

“Log(a) / Log(b)" means "depow"
“a ^ (1/b)” means "unpow"

a
b
depow


a
b
unpow

This way the result will be an approximate whole but there will be no need for floating points in the DB code.

And yes my names need improvement: I don't think "unpow" and "depow" sounds professional enough.

P.S.

O yea, and I believe this topic belongs in the suggestions forum now...
Thank You for your time...

[Numsgil]

I think a general pow term actually isn't a great idea.  There's very little need to raise things to powers other than 1/3, 1/2, 2, or 3.  So I think a better solution would be to add cbrt, cube, and square commands.  Or something along those lines.

[Botsareus]

I have already added unpow and depow to my DB source code...

So If my evolved robot uses it I will have to post the vb code I changed. It's two new subs called DNAunpow and DNAdepow. DNA tokenizing and detokenizing was changed. etc.

[bacillus]

Just out of curiosity, what were you planning to use this for?

[Botsareus]

I hope that it will add more flexibility to my evolving robots. I don't plan to write my own robot, I am working on a system to generate a robot good enough for F1 mode...

[Prsn828]

I hope that it will add more flexibility to my evolving robots. I don't plan to write my own robot, I am working on a system to generate a robot good enough for F1 mode...

You know, I think the whole concept of Darwinbots began around that idea.  The thought that you can evolve a better bot, no matter how good the current one may be.  At least in my mind, that is what is so exciting.