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I am working on Python 2.7. I want to create nomograms based on the data of various variables in order to predict one variable. I am looking into and have installed PyNomo package.

However, the from the documentation here and here and the examples, it seems that nomograms can only be made when you have equation(s) relating these variables, and not from the data. For example, examples here show how to use equations to create nomograms. What I want, is to create a nomogram from the data and use that to predict things. How do I do that? In other words, how do I make the nomograph take data as input and not the function as input? Is it even possible?

Any input would be helpful. If PyNomo cannot do it, please suggest some other package (in any language). For example, I am trying function nomogram from package rms in R, but not having luck with figuring out how to properly use it. I have asked a separate question for that here.

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dc95
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  • Perhaps you could consider this a two step problem. Step one would be estimating the equations from your data and step two would be creating the nomogram from the equations. I or someone else might be able to help give a more thorough solution along these lines if you post more specifics about your data and objectives. – jcrudy Jul 15 '16 at 23:16
  • By more specifics, I mostly mean what is the source of the data and do you know something about the forms of the equations these data are thought to be generated from? For example, if you know the equations should be linear then you could use linear regression to get the coefficients and then plug those into pynomo. Your equations are probably more complicated than that, but may be amenable to some similar approach. – jcrudy Jul 15 '16 at 23:21

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The term "nomogram" has become somewhat confused of late as it now refers to two entirely different things.

A classic nomogram performs a full calculation - you mark two scales, draw a straight line across the marks and read your answer from a third scale. This is the type of nomogram that pynomo produces, and as you correctly say, you need a formula. As mentioned above, producing nomograms like this is definitely a two-step process.

The other use of the term (very popular, recently) is to refer to regression nomograms. These are graphical depictions of regression models (usually logistic regression models). For these, a group of parallel predictor variables are depicted with a common scale on the bottom; for each predictor you read the 'score' from the scale and add these up. These types of nomograms have become very popular in the last few years, and thats what the RMS package will draft. I haven't used this but my understanding is that it works directly from the data.

Hope this is of some use! :-)

Jason Walker
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