### Maths boffins wanted!

#### by subacati

I've forgotten most of the maths that I learnt in highschool! Now I need help! :faint:. …

Ok, so if you can remember your highschool maths, or even better, if you've done advanced, tertiary level maths, I need your help!

I'm working on a project involving artificial neural networks. Now I'm trying to modify a BASIC program to implimemt a back propagation algorithm.

The problem is, I've forgotten how to interpret maths formulae! :cry:.

To complicate matters, these formulae combine boolean with what appears to be calculus. :left:.

The authors of the source material I'm working with probably assumed that only someone studying at Varsity level (or who already has a degree) world bother to try to follow what they'd written. :p.

Anyway, here are the two formulae!

and

Now to expain! What I need to do, is convert these two formulae into BASIC programming statements.

in the first formula, O_{k} is represented in my BASIC program by S3%(K) and t_{k} is represented by S1%(K)

I'll probably use S0%(K) for _{}

Now S1%(K) and S3%(K) each hold a value of either 'true' or 'false'. Although these value are normally represented in binary as either 1 or 0 respectively, in the program I have, 'false' is represented by a negative number.

In the second equation, _{} represents "the sum of the weights". My main problem here is, I don't know where h comes from? :confused:.

Any help would be appreciated! :up:.

Thanks!

Give that a read on Opera Mini.

Shit! I forgot that Operamini doesn't support unicode! :bomb:.I'll have to take a screenshot! :up:.

Originally posted by qlue:

You lack a parenthesis there somewhere. 🙂

Originally posted by Amnith:

δk ← Ok(1 – Ok)(tk – Ok)I'll have to fix the image now! :p.@Mik is it more readable now?

Yeah. I believe h is expressed elsewhere or can be worked out in relation to k.

This isn't looking good. I was Calcuclueless as to what a Boffin was, be it the Math variety or otherwise. Strike One. Then as chronicled in one of my Posts, our Algebra teacher quit early on in my High School Freshman year. Thus, I know 1 step above SQUAT as far as Algebra goes. Strike Two. :doh: Then I haven't programmed in BASIC since 1987. Strike Three.But, don't despair, Aadil. That looks Greek.Ask Angeliki. So, would someone who is perpetually Bullshitting … be a BS Boffin?

Originally posted by Furie:

Thanks.I found another representation of the second eqation that helps to clarify it a little.$h = oh(1 – oh)#k in outputs wh,k $dSo I'm sure I'll be able to figure it out.But the first equation still has me stumped because The allowable values for Ok and Tk are 1 and 0 (or in my program 1 and -1) yet to multiply by zero leads to a result of zero thus the result will

alwaysbe zero.However, it appears to be a boolean function, so then we try ANDing instead. except that to AND anything with zeroalsogives us zero. :confused::faint:.So I'm clearly missing something important here! :left:.Originally posted by Suntana:Not really a requirement! :p.Actually, the original program I'm modifying is circa 1987. :left:.I'm pretty certain that standard Algebra is not enough to solve for s in this equation! :lol:.I've actually found a forty part series if lectures on YouTube dealing with artificial neural networks. each lecture is 1 hour long and back propagation is dealt with in lecture number nineteen! :faint:.Well, I guess I need to start at the beginning if I'm to understand the maths involved! :lol:.

Originally posted by Suntana:

😆 silly :phttp://www.computer.org/portal/web/csdl/doi/10.1109/IJCNN.2000.860795

Aadil, I have no idea what you are talking about anyway. Math was never my strong point and I quit taking math in school as soon as they allowed me to. That looks like an alien language to me. Sheesh!

Erm… Uh… Ahrm…. Sorry, I got nothing.

Well Linda, it is a kind of alien language. :p.@Rose. Well it's got nothing to do with shoes so… :whistle::p.

:p

I am very impressed just knowing you even know what that stuff is!

<looks at all the bright shiny words and numbers that flies over her head> :whoa:

:lol:.

Aadil, you're gonna have to change your Username to …

Mad Boffin.That is EXACTLY what I was thinking.

It will have to be, "befuddled boffin" 'cos I still don't have a qlue. :lol:.These formulae don't seem to work with my program. So either I'm, "doing it wrong," or these formulae are assuming some factor that's not covered in my algorithm. :rolleyes:.My mathematical understanding of the formulae appears to be correct though. But they just don't work with the data I get from my program. :left:.The first formula gives either an output of zero, or -2 with the input data I have. (if I first convert the 'low' bit from -1 to a zero, then the -2 becomes -1)And that doesn't make much sense. :irked:.I'm currently trying to develop a different approach of my own so that I can get my program to do what I want it to do. :up:.So it looks like I'm gonna be 'reinventing the wheel' on this one. :p.