Parallel coordinate graphs

Hiiiiii there

As I promised bofore, (I mean in my upcoming section) I would like to talk a little bit about parallel coordinate graphs which it counts as a one way to visualiz multivariate data.

So first lets see, what is this graph ?

Basically, this graph consist of n equaly spaced parallel vertical axes which each of these axes stands as a representative of one variable. A parallel coordinate plot maps each row in the data table as a line, or profile.

In order to get a better understanding of it, let me bring an example (This example has been brought from spotfire website). A laboratory has measured the amount of various carbohydrates contained in various fruit and vegetables. They have measured Glucose, Fructose, Maltose and Saccharose. As you can see in the figure above for each food type, it is now possible to plot a profile of how the carbohydrates are distributed. The technicians in the laboratory can now see which food types are similar to each other in carbohydrate distribution, by comparing the profiles to each other. This is where the parallel coordinate plot is really useful, to compare profiles in order to find similarities.

When doing multivariate analysis, the big picture is usually where you want to start, for meaningful observations, believe it or not, can be gleaned from the clutter. It's also necessary to mention that a display with this much data cannot be used to explore the details, but it can

be used to search for predominant patterns and exceptions.

I actually, found this graph very useful in terms of finding the big picture in some multivariate data in one of my own project. For further information you can take a look at here (http://en.wikipedia.org/wiki/Parallel_coordinates)

Good luck

hamze