supporting old versions of Numeric

Hi,

Old versions of Numeric (specifically, version 21) don't have symbols such at UInt8 defined. I modified nc_imports to deal with this case, but I wanted to fly it past the experts in case it misses some subtle intricacy.

Furthermore, I get the following bug when trying to run examples/simple_plot.py on Windows XP, matplotlib 0.54, Numeric 21. Is this fixable?

Traceback (most recent call last):
  File "simple_plot.py", line 16, in ?
    show()
  File "C:\Python22\Lib\site-packages\matplotlib\backends\backend_wx.py", line 1124, in show
    figwin.canvas.draw()
  File "C:\Python22\Lib\site-packages\matplotlib\backends\backend_wxagg.py", line 50, in draw
    agg.draw()
  File "C:\Python22\Lib\site-packages\matplotlib\backends\backend_agg.py", line 299, in draw
    self.figure.draw(self.renderer)
  File "C:\Python22\Lib\site-packages\matplotlib\figure.py", line 128, in draw
    for a in self.axes: a.draw(renderer)
  File "C:\Python22\Lib\site-packages\matplotlib\axes.py", line 603, in draw
    self.xaxis.draw(renderer)
  File "C:\Python22\Lib\site-packages\matplotlib\axis.py", line 463, in draw
    tick.draw(renderer)
  File "C:\Python22\Lib\site-packages\matplotlib\axis.py", line 130, in draw
    if self.label1On: self.label1.draw(renderer)
  File "C:\Python22\Lib\site-packages\matplotlib\text.py", line 193, in draw
    bbox, info = self._get_layout(renderer)
  File "C:\Python22\Lib\site-packages\matplotlib\text.py", line 129, in _get_layout
    txs = [float(v[0][0]) for v in cornersRotated]
  File "C:\Python22\Lib\site-packages\Numeric\UserArray.py", line 154, in __float__
    def __float__(self): return self._scalarfunc(float)
  File "C:\Python22\Lib\site-packages\Numeric\UserArray.py", line 151, in _scalarfunc
    raise TypeError, "only rank-0 arrays can be converted to Python scalars."
TypeError: only rank-0 arrays can be converted to Python scalars.

nc_imports.py (1.14 KB)