Source code for scitools.easyviz.pyx_
"""
This backend is based on the Python graphics package PyX which creates
PostScript and PDF files. The PyX backend does not produce any output until
the hardcopy method is called. One can specify this backend by
python somefile.py --SCITOOLS_easyviz_backend pyx
or one can specify the backend in the SciTools configuration file
scitools.cfg under the [easyviz] section
[easyviz]
backend = pyx
and then
from scitools.std import *
or if just easyviz is needed
from scitools.easyviz import *
REQUIREMENTS:
pyx
TODO:
- add support for mesh and surf (requires PyX from svn)
"""
from __future__ import division
from common import *
from scitools.globaldata import DEBUG, VERBOSE
from scitools.misc import test_if_module_exists
test_if_module_exists('pyx', msg='You need to install the PyX package.', abort=False)
import pyx
import math
[docs]class PyXBackend(BaseClass):
def _init(self, *args, **kwargs):
"""Perform initialization that is special for this backend."""
# Set docstrings of all functions to the docstrings of BaseClass
# The exception is if something is very different
self.figure(self.getp('curfig'))
# conversion tables for format strings:
self._markers = {
'': None, # no marker
'.': None, # dot
'o': pyx.graph.style.symbol.circle, # circle
'x': pyx.graph.style.symbol.cross, # cross
'+': pyx.graph.style.symbol.plus, # plus sign
'*': None, # asterisk
's': pyx.graph.style.symbol.square, # square
'd': pyx.graph.style.symbol.diamond, # diamond
'^': pyx.graph.style.symbol.triangle, # triangle (up)
'v': pyx.graph.style.symbol.triangle, # triangle (down)
'<': pyx.graph.style.symbol.triangle, # triangle (left)
'>': pyx.graph.style.symbol.triangle, # triangle (right)
'p': None, # pentagram
'h': None, # hexagram
}
self._colors = {
'': None, # no color --> blue
'r': pyx.graph.style.color.cmyk.Red, # red
'g': pyx.graph.style.color.cmyk.Green, # green
'b': pyx.graph.style.color.cmyk.Blue, # blue
'c': pyx.graph.style.color.cmyk.Cyan, # cyan
'm': pyx.graph.style.color.cmyk.Magenta, # magenta
'y': pyx.graph.style.color.cmyk.Yellow, # yellow
'k': pyx.graph.style.color.cmyk.Black, # black
'w': pyx.graph.style.color.cmyk.White, # white
}
self._line_styles = {
'': None, # no line
'-': pyx.style.linestyle.solid, # solid line
':': pyx.style.linestyle.dotted, # dotted line
'-.': pyx.style.linestyle.dashdotted, # dash-dot line
'--': pyx.style.linestyle.dashed # dashed line
}
# convert table for colorbar location:
self._colorbar_locations = {
'North': None,
'South': None,
'East': None,
'West': None,
'NorthOutside': None,
'SouthOutside': None,
'EastOutside': None,
'WestOutside': None,
}
if DEBUG:
print "Setting backend standard variables"
for disp in 'self._markers self._colors self._line_styles'.split():
print disp, eval(disp)
def _get_scale(self, ax):
# return a linear or logarithmic (base 10) axis
if DEBUG:
print "Get axis scales"
scale = ax.getp('scale')
if scale == 'loglog':
# use logarithmic scale on both x- and y-axis
xaxis = pyx.graph.axis.log
yaxis = pyx.graph.axis.log
elif scale == 'logx':
# use logarithmic scale on x-axis and linear scale on y-axis
xaxis = pyx.graph.axis.log
yaxis = pyx.graph.axis.lin
elif scale == 'logy':
# use linear scale on x-axis and logarithmic scale on y-axis
xaxis = pyx.graph.axis.lin
yaxis = pyx.graph.axis.log
elif scale == 'linear':
# use linear scale on both x- and y-axis
xaxis = pyx.graph.axis.lin
yaxis = pyx.graph.axis.lin
return xaxis, yaxis
def _set_labels(self, ax):
"""Add text labels for x-, y-, and z-axis."""
if DEBUG:
print "Setting labels"
xlabel = ax.getp('xlabel')
ylabel = ax.getp('ylabel')
zlabel = ax.getp('zlabel')
g = self._g.items[-1]
if xlabel:
# add a text label on x-axis
g.axes['x'].axis.title = xlabel
if ylabel:
# add a text label on y-axis
g.axes['y'].axis.title = ylabel
if zlabel:
# add a text label on z-axis
pass
def _set_title(self, ax):
"""Add a title at the top of the axis."""
if DEBUG:
print "Setting title"
title = ax.getp('title')
if title:
# set title
g = self._g.items[-1]
g.text(g.width/2+g.xpos, g.height+0.2+g.ypos, title,
[pyx.text.halign.center,
pyx.text.valign.bottom,
pyx.text.size.Large])
def _get_limits(self, ax):
# return axis limits in x, y, and z direction
if DEBUG:
print "Setting axis limits"
mode = ax.getp('mode')
limits = [None]*6
if mode == 'auto':
# let plotting package set 'nice' axis limits in the x, y,
# and z direction. If this is not automated in the plotting
# package, one can use the following limits:
#xmin, xmax, ymin, ymax, zmin, zmax = ax.get_limits()
pass
elif mode == 'manual':
# (some) axis limits are frozen
xmin = ax.getp('xmin')
xmax = ax.getp('xmax')
if xmin is not None and xmax is not None:
# set x-axis limits
limits[0] = xmin
limits[1] = xmax
else:
# let plotting package set x-axis limits or use
#xmin, xmax = ax.getp('xlim')
pass
ymin = ax.getp('ymin')
ymax = ax.getp('ymax')
if ymin is not None and ymax is not None:
# set y-axis limits
limits[2] = ymin
limits[3] = ymax
else:
# let plotting package set y-axis limits or use
#ymin, ymax = ax.getp('ylim')
pass
zmin = ax.getp('zmin')
zmax = ax.getp('zmax')
if zmin and zmax:
# set z-axis limits
limits[4] = zmin
limits[5] = zmax
else:
# let plotting package set z-axis limits or use
#zmin, zmax = ax.getp('zlim')
pass
elif mode == 'tight':
# set the limits on the axis to the range of the data. If
# this is not automated in the plotting package, one can
# use the following limits:
#xmin, xmax, ymin, ymax, zmin, zmax = ax.get_limits()
limits = ax.get_limits()
elif mode == 'fill':
# not sure about this
pass
return limits
def _set_position(self, ax):
"""Set axes position."""
rect = ax.getp('viewport')
if rect:
# axes position is defined. In Matlab rect is defined as
# [left,bottom,width,height], where the four parameters are
# location values between 0 and 1 ((0,0) is the lower-left
# corner and (1,1) is the upper-right corner).
# NOTE: This can be different in the plotting package.
pass
def _set_daspect(self, ax):
"""Set data aspect ratio."""
if ax.getp('daspectmode') == 'manual':
dar = ax.getp('daspect') # dar is a list (len(dar) is 3).
pass
else:
# daspectmode is 'auto'. Plotting package handles data
# aspect ratio automatically.
pass
def _set_axis_method(self, ax):
method = ax.getp('method')
if method == 'equal':
# tick mark increments on the x-, y-, and z-axis should
# be equal in size.
pass
elif method == 'image':
# same effect as axis('equal') and axis('tight')
pass
elif method == 'square':
# make the axis box square in size
pass
elif method == 'normal':
# full size axis box
pass
elif method == 'vis3d':
# freeze data aspect ratio when rotating 3D objects
pass
def _set_coordinate_system(self, ax):
"""
Use either the default Cartesian coordinate system or a
matrix coordinate system.
"""
direction = ax.getp('direction')
if direction == 'ij':
# Use matrix coordinates. The origin of the coordinate
# system is the upper-left corner. The i-axis should be
# vertical and numbered from top to bottom, while the j-axis
# should be horizontal and numbered from left to right.
pass
elif direction == 'xy':
# use the default Cartesian axes form. The origin is at the
# lower-left corner. The x-axis is vertical and numbered
# from left to right, while the y-axis is vertical and
# numbered from bottom to top.
pass
def _set_box(self, ax):
"""Turn box around axes boundary on or off."""
if DEBUG:
print "Setting box"
if ax.getp('box'):
# display box
pass
else:
# do not display box
pass
def _set_grid(self, ax):
"""Turn grid lines on or off."""
if DEBUG:
print "Setting grid"
if ax.getp('grid'):
# turn grid lines on
pass
else:
# turn grid lines off
pass
def _set_hidden_line_removal(self, ax):
"""Turn on/off hidden line removal for meshes."""
if DEBUG:
print "Setting hidden line removal"
if ax.getp('hidden'):
# turn hidden line removal on
pass
else:
# turn hidden line removal off
pass
def _set_colorbar(self, ax):
"""Add a colorbar to the axis."""
if DEBUG:
print "Setting colorbar"
cbar = ax.getp('colorbar')
if cbar.getp('visible'):
# turn on colorbar
cbar_title = cbar.getp('cbtitle')
cbar_location = self._colorbar_locations[cbar.getp('cblocation')]
# ...
else:
# turn off colorbar
pass
def _set_caxis(self, ax):
"""Set the color axis scale."""
if DEBUG:
print "Setting caxis"
if ax.getp('caxismode') == 'manual':
cmin, cmax = ax.getp('caxis')
# NOTE: cmin and cmax might be None:
if cmin is None or cmax is None:
cmin, cmax = [0,1]
# set color axis scaling according to cmin and cmax
pass
else:
# use autoranging for color axis scale
pass
def _set_colormap(self, ax):
"""Set the colormap."""
if DEBUG:
print "Setting colormap"
cmap = ax.getp('colormap')
# cmap is plotting package dependent
def _set_view(self, ax):
"""Set viewpoint specification."""
if DEBUG:
print "Setting view"
cam = ax.getp('camera')
view = cam.getp('view')
if view == 2:
# setup a default 2D view
pass
elif view == 3:
az = cam.getp('azimuth')
el = cam.getp('elevation')
if az is None or el is None:
# azimuth or elevation is not given. Set up a default
# 3D view (az=-37.5 and el=30 is the default 3D view in
# Matlab).
pass
else:
# set a 3D view according to az and el
pass
if cam.getp('cammode') == 'manual':
# for advanced camera handling:
roll = cam.getp('camroll')
zoom = cam.getp('camzoom')
dolly = cam.getp('camdolly')
target = cam.getp('camtarget')
position = cam.getp('campos')
up_vector = cam.getp('camup')
view_angle = cam.getp('camva')
projection = cam.getp('camproj')
def _set_axis_props(self, ax):
if DEBUG:
print "Setting axis properties"
self._set_title(ax)
self._set_position(ax)
self._set_axis_method(ax)
self._set_daspect(ax)
self._set_coordinate_system(ax)
self._set_hidden_line_removal(ax)
self._set_colorbar(ax)
self._set_caxis(ax)
self._set_colormap(ax)
self._set_view(ax)
if ax.getp('visible'):
self._set_labels(ax)
self._set_box(ax)
self._set_grid(ax)
else:
# turn off all axis labeling, tickmarks, and background
pass
def _get_linespecs(self, item):
"""
Return the line marker, line color, line style, and
line width of the item.
"""
marker = self._markers[item.getp('linemarker')]
color = self._colors[item.getp('linecolor')]
style = self._line_styles[item.getp('linetype')]
width = item.getp('linewidth')
if width:
width = pyx.style.linewidth(float(width)*pyx.unit.w_pt)
return marker, color, style, width
def _add_line(self, item):
"""Add a 2D or 3D curve to the scene."""
if DEBUG:
print "Adding a line"
# get data:
x = item.getp('xdata')
y = item.getp('ydata')
z = item.getp('zdata')
# get line specifiactions:
marker, color, style, width = self._get_linespecs(item)
styles = []
lineattrs = []
if style:
lineattrs.append(style)
if color:
lineattrs.append(color)
if width:
lineattrs.append(width)
styles.append(pyx.graph.style.line(lineattrs=lineattrs))
if marker:
if color:
styles.append(pyx.graph.style.symbol(marker,
symbolattrs=[color]))
else:
styles.append(pyx.graph.style.symbol(marker))
else:
if not styles:
styles = [pyx.graph.style.line([pyx.color.gradient.Rainbow])]
data = []
if z is not None:
# zdata is given, add a 3D curve:
pass
else:
# no zdata, add a 2D curve:
for i in range(len(x)):
data.append([x[i], y[i]])
legend = item.getp('legend')
if not legend:
legend = None
self._g.items[-1].plot(pyx.graph.data.points(data,x=1,y=2,title=legend),
styles=styles)
def _add_surface(self, item, shading='faceted'):
if DEBUG:
print "Adding a surface"
x = squeeze(item.getp('xdata')) # grid component in x-direction
y = squeeze(item.getp('ydata')) # grid component in y-direction
z = item.getp('zdata') # scalar field
c = item.getp('cdata') # pseudocolor data (can be None)
data = []
m, n = shape(z)
if shape(x) != (m,n) and shape(y) != (m,n):
x, y = ndgrid(x,y,sparse=False)
for i in range(m):
for j in range(n):
data.append([x[i,j], y[i,j], z[i,j]])
contours = item.getp('contours')
if contours:
# the current item is produced by meshc or surfc and we
# should therefore add contours at the bottom:
self._add_contours(contours, placement='bottom')
styles = []
if item.getp('wireframe'):
# wireframe mesh (as produced by mesh or meshc)
styles.append(pyx.graph.style.line())
else:
# colored surface (as produced by surf, surfc, or pcolor)
# use keyword argument shading to set the color shading mode
styles.append(pyx.graph.style.surface())
legend = item.getp('legend')
if not legend:
legend = None
g = self._g.items[-1]
g.plot(pyx.graph.data.list(data, x=1, y=2, color=3, title=legend),
styles=styles)
g.dodata()
def _add_contours(self, item, placement=None):
# The placement keyword can be either None or 'bottom'. The
# latter specifies that the contours should be placed at the
# bottom (as in meshc or surfc).
if DEBUG:
print "Adding contours"
x = item.getp('xdata') # grid component in x-direction
y = item.getp('ydata') # grid component in y-direction
z = item.getp('zdata') # scalar field
filled = item.getp('filled') # draw filled contour plot if True
cvector = item.getp('cvector')
clevels = item.getp('clevels') # number of contour levels
if cvector is None:
# the contour levels are chosen automatically
#cvector =
pass
location = item.getp('clocation')
if location == 'surface':
# place the contours at the corresponding z level (contour3)
pass
elif location == 'base':
if placement == 'bottom':
# place the contours at the bottom (as in meshc or surfc)
pass
else:
# standard contour plot
pass
if item.getp('clabels'):
# add labels on the contour curves
pass
def _add_vectors(self, item):
if DEBUG:
print "Adding vectors"
# uncomment the following command if there is no support for
# automatic scaling of vectors in the current plotting package:
#item.scale_vectors()
# grid components:
x, y, z = item.getp('xdata'), item.getp('ydata'), item.getp('zdata')
# vector components:
u, v, w = item.getp('udata'), item.getp('vdata'), item.getp('wdata')
# get line specifiactions (marker='.' means no marker):
marker, color, style, width = self._get_linespecs(item)
# scale the vectors according to this variable (scale=0 should
# turn off automatic scaling):
scale = item.getp('arrowscale')
filled = item.getp('filledarrows') # draw filled arrows if True
if z is not None and w is not None:
# draw velocity vectors as arrows with components (u,v,w) at
# points (x,y,z):
pass
else:
# draw velocity vectors as arrows with components (u,v) at
# points (x,y):
pass
def _add_streams(self, item):
if DEBUG:
print "Adding streams"
# grid components:
x, y, z = item.getp('xdata'), item.getp('ydata'), item.getp('zdata')
# vector components:
u, v, w = item.getp('udata'), item.getp('vdata'), item.getp('wdata')
# starting positions for streams:
sx, sy, sz = item.getp('startx'), item.getp('starty'), item.getp('startz')
if item.getp('tubes'):
# draw stream tubes from vector data (u,v,w) at points (x,y,z)
n = item.getp('n') # no points along the circumference of the tube
scale = item.getp('tubescale')
pass
elif item.getp('ribbons'):
# draw stream ribbons from vector data (u,v,w) at points (x,y,z)
width = item.getp('ribbonwidth')
pass
else:
if z is not None and w is not None:
# draw stream lines from vector data (u,v,w) at points (x,y,z)
pass
else:
# draw stream lines from vector data (u,v) at points (x,y)
pass
pass
def _add_isosurface(self, item):
if DEBUG:
print "Adding a isosurface"
# grid components:
x, y, z = item.getp('xdata'), item.getp('ydata'), item.getp('zdata')
v = item.getp('vdata') # volume
c = item.getp('cdata') # pseudocolor data
isovalue = item.getp('isovalue')
def _add_slices(self, item):
if DEBUG:
print "Adding slices in a volume"
# grid components:
x, y, z = item.getp('xdata'), item.getp('ydata'), item.getp('zdata')
v = item.getp('vdata') # volume
sx, sy, sz = item.getp('slices')
if rank(sz) == 2:
# sx, sy, and sz defines a surface
pass
else:
# sx, sy, and sz is either numbers or vectors with numbers
pass
pass
def _add_contourslices(self, item):
if DEBUG:
print "Adding contours in slice planes"
# grid components:
x, y, z = item.getp('xdata'), item.getp('ydata'), item.getp('zdata')
v = item.getp('vdata') # volume
sx, sy, sz = item.getp('slices')
if rank(sz) == 2:
# sx, sy, and sz defines a surface
pass
else:
# sx, sy, and sz is either numbers or vectors with numbers
pass
cvector = item.getp('cvector')
clevels = item.getp('clevels') # number of contour levels per plane
if cvector is None:
# the contour levels are chosen automatically
#cvector =
pass
pass
def _get_figure_size(self, fig):
if DEBUG:
print "Get figure size"
width, height = fig.getp('size')
if width is None or height is None:
# use the default width and height in plotting package
width = 15
ratio = 0.5*(math.sqrt(5)+1) # golden mean
height = (1.0/ratio)*width
return width, height
[docs] def figure(self, *args, **kwargs):
# Extension of BaseClass.figure:
# add a plotting package figure instance as fig._g and create a
# link to it as self._g
fig = BaseClass.figure(self, *args, **kwargs)
try:
fig._g
except:
# create plotting package figure and save figure instance
# as fig._g
if DEBUG:
name = 'Fig ' + str(fig.getp('number'))
print "creating figure %s in backend" % name
fig._g = pyx.canvas.canvas()
self._g = fig._g # link for faster access
return fig
def _replot(self):
"""Replot all axes and all plotitems in the backend."""
# NOTE: only the current figure (gcf) is redrawn.
if DEBUG:
print "Doing replot in backend"
fig = self.gcf()
# reset the plotting package instance in fig._g now if needed
self._g.items = []
width, height = self._get_figure_size(fig)
xpos = 0; ypos = 0
tmp_xpos = 0; tmp_ypos = 0
row = 1; column = 1
nrows, ncolumns = fig.getp('axshape')
sbsp = 1.8 # space between subplots
w = width/ncolumns-sbsp # subplot width
h = height/nrows-sbsp # subplot height
for axnr, ax in fig.getp('axes').items():
legends = False
xaxis, yaxis = self._get_scale(ax)
xmin, xmax, ymin, ymax, zmin, zmax = self._get_limits(ax)
kwargs = {'x': xaxis(min=xmin, max=xmax),
'y': yaxis(min=ymin, max=ymax)}
pth = ax.getp('pth')
if pth:
# create axes in tiled position
# this is subplot(nrows,ncolumns,pth)
xpos = tmp_xpos; ypos = tmp_ypos
if column < ncolumns:
column += 1
tmp_xpos += w + sbsp
else:
column = 1
tmp_xpos = 0
if row <= nrows:
row += 1
tmp_ypos -= h + sbsp
kwargs.update({'width': w, 'height': h})
else:
rect = ax.getp('viewport')
if rect is not None:
xpos, ypos, width, height = rect
kwargs.update({'width': width, 'height': height})
graph = pyx.graph.graphxy(xpos, ypos, **kwargs)
#graph = pyx.graph.graphxyz(xpos, ypos, width=5, height=5, depth=5)
plotitems = ax.getp('plotitems')
plotitems.sort(self._cmpPlotProperties)
if plotitems:
self._g.insert(graph) # insert graph into figure canvas
self._set_axis_props(ax)
for item in plotitems:
func = item.getp('function') # function that produced this item
if isinstance(item, Line):
self._add_line(item)
elif isinstance(item, Surface):
self._add_surface(item, shading=ax.getp('shading'))
elif isinstance(item, Contours):
self._add_contours(item)
elif isinstance(item, VelocityVectors):
self._add_vectors(item)
elif isinstance(item, Streams):
self._add_streams(item)
elif isinstance(item, Volume):
if func == 'isosurface':
self._add_isosurface(item)
elif func == 'slice_':
self._add_slices(item)
elif func == 'contourslice':
self._add_contourslices(item)
legend = item.getp('legend')
if legend:
# add legend to plot
legends = True
if legends:
graph.key = pyx.graph.key.key(pos="tr", dist=0.1)
if self.getp('show'):
# display plot on the screen
if DEBUG:
print "\nDumping plot data to screen\n"
debug(self)
pass
[docs] def hardcopy(self, filename, **kwargs):
"""
Supported extensions: .pdf, .ps, .eps
"""
self.setp(**kwargs)
color = self.getp('color')
replot = kwargs.get('replot', True)
if replot:
self._replot()
if DEBUG:
print "Hardcopy to %s" % filename
basename, ext = os.path.splitext(filename)
if not ext:
# no extension given, assume PostScript
filename += '.ps'
self._g.writetofile(filename)
# reimplement methods like clf, closefig, closefigs
[docs] def clf(self):
fig = self.gcf()
del fig._g
BaseClass.clf(self)
# implement colormap functions here
#def jet(self, m=None):
# """Variant of hsv."""
# pass
# Now we add the doc string from the methods in BaseClass to the
# methods that are reimplemented in this backend:
for cmd in BaseClass._matlab_like_cmds:
if not '__' in cmd and hasattr(BaseClass, cmd):
m1 = eval('BaseClass.%s' % cmd)
try:
m2 = eval('%s' % cmd)
except NameError:
pass
else:
if m1.__doc__ != m2.__doc__:
if m2.__doc__ is None:
m2.__doc__ = ""
m2.__doc__ = m1.__doc__ + m2.__doc__
plt = PyXBackend() # create backend instance
use(plt, globals()) # export public namespace of plt to globals()
backend = os.path.splitext(os.path.basename(__file__))[0][:-1]
