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Plotting contour & filled.contour in one graph

GG

Yes, gladly.  It is an idealized example of the following data 
situation:  There are two control or "independent variables."  They are 
represented here as x and y, on the horizontal and vertical axes 
respectively.  There are two different responses or "dependent" 
variables plotted as different types of contours.  The filled contours 
show response z.  The heavy lines show response zz.

Thus such a plot displays two different responses from a two-dimensional 
range of conditions.  As an example, in fishery biology, x might be the 
age at which fish are first subject to capture, y might be the fishing 
mortality rate (intensity) applied, z might be the resulting yield per 
fish, and zz might be the resulting spawning per fish.  There is usually 
a trade-off between yield and spawning potential, and such a graph (if 
done with real data) allows one to look at that trade-off. 

The OP seemed to be seeking a way of contouring two responses against 
two independent variables, and that's what this graph does.

Is that clearer?  Would the graph would be better if I used real data?

MHP



Gabor Grothendieck wrote on 2/12/2006 11:31 AM: