How to Map Two Tables To One Class in Fluent NHibernate?

What differentiates a heat map from other maps?

• My friends and I got into a debate at lunch the other day. I am a data person and to me a heat map is simply a way to add a third dimension of data to a 2d map (define as a diagram where location and scale is relevant) using color as a way to visualize another dimension.  This other dimension could be as simple as the intensity of the relationship between the first two dimensions or an entirely different dimension of data.  My friend, who is a scientist,  said that only one dimension of data is needed for a heat map and gave example such as a map for the grades of students in a class.   In this case the order of the student doesn't matter    Is this still a heat "map"? And isnt what he is describing still three dimensions regardless if the location on the map is I irrelevant, ie still two dimensions.  Are we talking at cross purposes?  Am I missing something?

• Answer:

  A Heat Map is a color 2D representation of data (http://en.wikipedia.org/wiki/Heat_map). Thus the color is used to display a third dimension. What the three dimensions are does not really matter. It could be a choropleth where statistical data is overlaid on an actual map; it could be a thermal image overlay of a city; It could also be utterly "abstract", where the dimensions are any X and Y with color representing the state, as in the picture below. (Image from Wikipedia) I guess you could make a one dimensional line and use color for the second dimension instead of doing a 2D plot. Some (like you friend) might call that a Heat Map, but I'd ask why he was making the data hard to read. I don't see how you could just do this with one dimension of data, as you write. I think you misstated and there were two dimensions.