[PyX-user] symbol settings per dataset? (PyX 0.8)

[John O. <joh...@ya...>]

First, what a nice release; everything transitioned very nicely.

I would like to draw graphs with the following properties:

- My graph uses several datasets on the same graph.
- I'd like each dataset to have a separate symbol with its own color.

For instance, I'd like to write the following code:

for dataset in datasets:
  g.plot(graph.data.list(dataset),
            graph.style.symbol.next())

where the next() call would somehow increment the color and/or symbol type
of the dataset. (This would be a great example, actually; a 3-dataset graph, 
where the first dataset is, say, red crosses, the second dataset is green
plusses, and the third dataset is blue squares.)

Instead I'm doing something that I think is pretty kludgey:

[graph.style.symbol(gSymbol.getSymbol(),
                               symbolattrs=[deco.filled,
                                           
deco.stroked([gSymbol.getColor()])])])

which uses a class Symbol (below, with getSymbol() and getColor() member
functions). I would be very happy if someone could direct me toward writing
better code than what I've encapsulated in this class.

This seems like a function which ought to be built in. I think the 
"color.palette.Rainbow" is probably a good start, but it is not documented at
all in the manual. 

I would also appreciate a little better explanation of the "attrs"/changelist
objects ("barattrs", "symbolattrs", etc.) which don't appear to be documented
either (sorry if I missed them). "changecross" etc. also appear to fall in this
category. It seems like these are nice lists that could be used to step
through,
but I'd like to see a little more explanation of how it's used, since I haven't
found a good example.

Thanks! This is a wonderful package. Keep up the great work.

JDO

class Symbol:
  def __init__(self):
    self.symbols = (graph.style.symbol.cross,
                    graph.style.symbol.plus,
                    graph.style.symbol.square,
                    graph.style.symbol.triangle,
                    graph.style.symbol.circle,
                    graph.style.symbol.diamond,
                    )
    self.sidx = 0
    self.colors = (color.rgb.red,
                   color.rgb.green,
                   color.rgb.blue,
                   )
    self.cidx = 0
  def getSymbol(self):
    s = self.symbols[self.sidx]
    self.sidx += 1
    if self.sidx > len(self.symbols):
      self.sidx = 0
    return s
  def getColor(self):
    c = self.colors[self.cidx]
    self.cidx += 1
    if self.cidx > len(self.colors):
      self.cidx = 0
    return c


		
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