Search found 56 matches

by Leif
Sun Mar 16, 2008 9:06 pm
Forum: Mathematics
Topic: 4 variable nomogram article
Replies: 5
Views: 34550

Re: 4 variable nomogram article

I looked Allcock's book about grid-nomographs and there seems to be nothing special about grid nomograms compared with line nomograms made by constructional determinant. One has to make projective transformation from four original points to for destination points. Case f+g+h=0 may be an exception. O...
by Leif
Tue Mar 11, 2008 6:18 pm
Forum: Mathematics
Topic: Half of a mortgage nomogram
Replies: 9
Views: 43090

Re: Half of a mortgage nomogram

I downloaded your PyNomo program and all the associated software (I already had MiKTeX) and I'm starting to explore it. Very impressive. Ron Note that I made loan nomogram with the PyNomo version under development. The Sourceforge latest version 0.1.0b1 is from October and it will take some time be...
by Leif
Mon Mar 10, 2008 9:06 pm
Forum: Mathematics
Topic: Multiple scales on one curve
Replies: 3
Views: 25104

Re: Multiple scales on one curve

Hi All, I've looked more into using Weierstrass' Elliptic Functions to create a nomogram, and I've posted an essay with the details: http://myreckonings.com/wordpress/2008/02/24/a-zoomorphic-nomogram/ Ron Nice nomogram with a combination of art and math ! I've never seen Epstein's book. Has anyone ...
by Leif
Mon Mar 10, 2008 8:49 pm
Forum: Mathematics
Topic: Half of a mortgage nomogram
Replies: 9
Views: 43090

Re: Half of a mortgage nomogram

I have been working on the PyNomo project and as an demonstration managed to make amortization nomogram with exact equation. Half of nomogram is in spirit of nomogram from d'Ocagne 1899 book page 306. The nomogram may be downloaded from: http://pynomo.org/examples/amortization_100308.pdf I have work...
by Leif
Fri Feb 08, 2008 8:13 pm
Forum: Mathematics
Topic: Half of a mortgage nomogram
Replies: 9
Views: 43090

Great nomogram! How about if you would just fit coeffs for polynomials F1,F2,G2,F3 in function F1(a)=F2(n)+G2(n)*F3(i) such that error would be minimized for every combination of a,n,i in specified range ? This is of course the approach I already proposed. I looked my code and found that I actually ...
by Leif
Sun Feb 03, 2008 10:18 am
Forum: Mathematics
Topic: Two straight scales with a weird curvy scale in the middle
Replies: 9
Views: 47785

For interest, I think it was 1% to 10% and 5 to 50 years. By polynomials I got somewhere of 4% maximum error if I recall right. It was anyway little too much. For transformations: transformations do not change the basic equation. But maybe transformation could be such that in inaccurate region readi...
by Leif
Sat Feb 02, 2008 1:25 pm
Forum: Mathematics
Topic: Two straight scales with a weird curvy scale in the middle
Replies: 9
Views: 47785

My feeling is, that by taking the most general three variable nomogram of form g(u){ f(v) - f(w) } + g(v){ f(w) - f(u) } + g(w){ f(u) - f(v) } = 0 [see. e.g. http://www.projectrho.com/nomogram/standardForms.html] and fit polynomials to all six functions to match the real equation, one can get closes...
by Leif
Thu Jan 31, 2008 8:12 pm
Forum: Mathematics
Topic: Two straight scales with a weird curvy scale in the middle
Replies: 9
Views: 47785

If I understand correctly, this is close to a term "rectification of curves" that is discussed e.g. in Ref. [p. 180, Levens, 2nd Ed, 1965]. The question is how one can make log(f(x))-log(g(y)) plots where all curves g(z)=const are straight lines. Sometimes this does not work out and result...
by Leif
Sun Jan 27, 2008 11:41 am
Forum: Mathematics
Topic: Multiple scales on one curve
Replies: 3
Views: 25104

I don't know or own the book (yet). Ordered it in order to find out...
http://www.abebooks.com/servlet/SearchR ... y&x=55&y=9


\leif
by Leif
Fri Jan 25, 2008 7:52 pm
Forum: Literature
Topic: Best books on nomography ?
Replies: 12
Views: 84970

Have you seen Winchell Chung's pages? e.g. http://www.projectrho.com/nomogram/standardForms.html He has an extensive bibliography, with short reviews of many of the books: http://www.projectrho.com/nomogram/reading.html It is my understanding that Winchell has written a fair bit of nomography code ...
by Leif
Sat Jan 05, 2008 11:59 am
Forum: Literature
Topic: Best books on nomography ?
Replies: 12
Views: 84970

Best books on nomography ?

I'm interested about nomography books. I have bought quite many of them, but many of them are not very mathematical and most of them discusses same topics. The book "Otto: Nomography" is an exception and it discusses also some mathematical tricks to make determinants and criteria for nomog...

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