scigraph datasets mixin behavior

[John Phillips]

Hello, I have recently started trying to use the scigraph package in
McClim for a simulation course I'm taking.

I spent more time than I care to admit this morning trying to get a
scatter plot dataset to show up -- I kept getting the graph with tick
marks but no data. Finally after reading the code I found out that the
hidden-datasets member of the graph-datasets-mixin object will by
default initialize to be a copy of the datasets member.

For example if I do something like this:

(setf *my-graph* (make-instance 'graph:graph :datasets (list
*my-graph-data*) :hidden-datasets nil))

And then this:

(graph::hidden-datasets *my-graph*)

I get:

(#<GRAPH-DATA GRAPH-DATA-15>)

In other words, all the datasets are hidden by default. Is this the way
the class is meant to behave? If so, I feel like I must be doing
something wrong in the way I'm constructing my graph -- although it does
work (I manually set the hidden-datasets member to nil after
construction). Is there anywhere where I can find example usages of this
package?  There don't seem to be scigraph examples in the Examples/
folder, the things that say 'graph' usually seem to be manual graph
creations.

Thanks,
  John