"""
This module is to support *bbox_inches* option in savefig command.
"""
import warnings
from matplotlib.transforms import Bbox, TransformedBbox, Affine2D
def adjust_bbox(fig, format, bbox_inches):
"""
Temporarily adjust the figure so that only the specified area
(bbox_inches) is saved.
It modifies fig.bbox, fig.bbox_inches,
fig.transFigure._boxout, and fig.patch. While the figure size
changes, the scale of the original figure is conserved. A
function whitch restores the original values are returned.
"""
origBbox = fig.bbox
origBboxInches = fig.bbox_inches
_boxout = fig.transFigure._boxout
asp_list = []
locator_list = []
for ax in fig.axes:
pos = ax.get_position(original=False).frozen()
locator_list.append(ax.get_axes_locator())
asp_list.append(ax.get_aspect())
def _l(a, r, pos=pos): return pos
ax.set_axes_locator(_l)
ax.set_aspect("auto")
def restore_bbox():
for ax, asp, loc in zip(fig.axes, asp_list, locator_list):
ax.set_aspect(asp)
ax.set_axes_locator(loc)
fig.bbox = origBbox
fig.bbox_inches = origBboxInches
fig.transFigure._boxout = _boxout
fig.transFigure.invalidate()
fig.patch.set_bounds(0, 0, 1, 1)
if format in ["png", "raw", "rgba"]:
adjust_bbox_png(fig, bbox_inches)
return restore_bbox
elif format in ["pdf", "eps", "svg", "svgz"]:
adjust_bbox_pdf(fig, bbox_inches)
return restore_bbox
else:
warnings.warn("bbox_inches option for %s backend is not implemented yet." % (format))
return None
def adjust_bbox_png(fig, bbox_inches):
"""
adjust_bbox for png (Agg) format
"""
tr = fig.dpi_scale_trans
_bbox = TransformedBbox(bbox_inches,
tr)
x0, y0 = _bbox.x0, _bbox.y0
fig.bbox_inches = Bbox.from_bounds(0, 0,
bbox_inches.width,
bbox_inches.height)
x0, y0 = _bbox.x0, _bbox.y0
w1, h1 = fig.bbox.width, fig.bbox.height
fig.transFigure._boxout = Bbox.from_bounds(-x0, -y0,
w1, h1)
fig.transFigure.invalidate()
fig.bbox = TransformedBbox(fig.bbox_inches, tr)
fig.patch.set_bounds(x0/w1, y0/h1,
fig.bbox.width/w1, fig.bbox.height/h1)
def adjust_bbox_pdf(fig, bbox_inches):
"""
adjust_bbox for pdf & eps format
"""
tr = Affine2D().scale(72)
_bbox = TransformedBbox(bbox_inches, tr)
fig.bbox_inches = Bbox.from_bounds(0, 0,
bbox_inches.width,
bbox_inches.height)
x0, y0 = _bbox.x0, _bbox.y0
f = 72. / fig.dpi
w1, h1 = fig.bbox.width*f, fig.bbox.height*f
fig.transFigure._boxout = Bbox.from_bounds(-x0, -y0,
w1, h1)
fig.transFigure.invalidate()
fig.bbox = TransformedBbox(fig.bbox_inches, tr)
fig.patch.set_bounds(x0/w1, y0/h1,
fig.bbox.width/w1, fig.bbox.height/h1)
def process_figure_for_rasterizing(figure,
bbox_inches_restore, mode):
"""
This need to be called when figure dpi changes during the drawing
(e.g., rasterizing). It recovers the bbox and re-adjust it with
the new dpi.
"""
bbox_inches, restore_bbox = bbox_inches_restore
restore_bbox()
r = adjust_bbox(figure, mode,
bbox_inches)
return bbox_inches, r
