Talk:Nomogram

Not nomograms

Not all of the examples here seem to be nomograms. Tephigrams, for example are not nomograms, but rather non-linear graphs. The defining characteristic of a nomogram is, I believe, that calculations are performed by drawing a straight line between labelled points on two scaled curves and seeing where the line intersects a third scaled curve. Comments? --macrakis (talk) 20:36, 22 January 2009 (UTC)

I have updated the article to say that Tephigrams and other graphical calculators are not strictly nomograms, although they are often described as such. I have also replaced the top figure of a Smith Chart with a true parallel-scale nomogram. Rrrddd (talk) 01:08, 22 January 2012 (UTC)

Actually, I believe this definition of nomograms is too restrictive, and applies to a particular subset of nomograms (alignment nomograms). The term has certainly been used far more broadly. Glenbarnett (talk) 03:50, 10 December 2012 (UTC)

Insufficient explanation for chi-squared test nomogram

In Nomogram#Chi-squared_test_computation_nomogram, what does the ABCDE stand for? Mikael Häggström (talk) 10:31, 14 June 2010 (UTC)

I have added a paragraph that describes the function of the five lettered scales. Rrrddd (talk) 01:08, 22 January 2012 (UTC)

n-variate nomograms

Wow, nomograms are AWESOME. Especially the Parallel-resistance/thin-lens nomogram. Can't believe I've never come across that visualization before. It is soooo insightful.

The article says "A nomogram consists of a set of n scales. Knowing the values of n-1 variables, the value of the unknown variable can be found ... by laying a straightedge across the known values on the scales" which suggests that nomograms can model functions of any number of variables.

But how can this be done for any value of n other than 3? Assuming the nomogram is printed on a flat surface, the straightedge has only 2 degrees of freedom. Therefore 2 known variables define the line (and therefore the result) completely, and no further known variables can influence the result.

The only way I can think of getting around this is to use more straight edges with "intermediate result" scales on the monogram. This would effectively mean combining multiple sequential monograms on the same surface, using, for example, a bivariate function nested within a bivariate function to model a trivariate function. But the article mentions nothing about multiple straightedges, so I'm wondering why it says "n-1 knowns" rather than "2 knowns".

--Tennenrishin (talk) 11:12, 4 October 2013 (UTC)

Have a look at http://myreckonings.com/wordpress/2008/01/09/the-art-of-nomography-i-geometric-design/, search for "4-Variable Charts"

--alex (talk) 08:28, 28 September 2014 (UTC)

Not sure if I understand this correctly, but we use what I believe is a type of nomogram for backup/degraded mode firing solutions in U.S. Field Artillery, called a Graphic Firing Table (GFT), derived from a Tabular Firing Table (TFT: talk about a redundant term). When we derive a firing solution from corrected data, we apply that solution to the nomogram using thin lead pencil or superfine alcohol pens. That correction can be a simple "single-plot GFT setting", two-plot, or multi-plot GFT setting. With the two-plot and multi-plot GFT settings, the user defines the graphic index line as lines between corrected trajectory data points from data corrections derived from meteorological data and weapon corrections (muzzle velocity, etc.). The more and closer together the data points, the more curve-like the index line.Caisson 06 (talk) 20:11, 11 May 2015 (UTC)

ABACs

A book of radio/electronic nomograms I once used, they were called ABACs. Doug butler (talk) 08:28, 11 May 2021 (UTC)