Hello,

I have a set of data I wish to graph in a scatterplot. Each data point
has two identification codes, coming from two separate groups, e.g., L
= {a,b,c,d,e} and C = {1,2,3,4}. So you might have points

a 1 1.3 5.4
a 2 2.4 2.3
b 1 4.5 3.2
b 3 8.9 6.7

and so on. Each combination of items from L and C is present.
Moreover, for each (l,c) tuple, I have multiple data points.

I wish to use both colour and shape to identify the data points, e.g.
all a's should be yellow, all b's red, etc. and all 1's should be a
triangle, all 2's a square etc.

I can use series and the vary color by point, but then points with the
same L-value will still get distinct colors.

Any pointers on how to do this?