SF.net SVN: matplotlib: [3837] branches/transforms/lib/matplotlib/pbox.py

[<md...@us...>]

Revision: 3837
          http://matplotlib.svn.sourceforge.net/matplotlib/?rev=3837&view=rev
Author:   mdboom
Date:     2007-09-12 07:46:03 -0700 (Wed, 12 Sep 2007)

Log Message:
-----------
Adding pbox.py

Added Paths:
-----------
    branches/transforms/lib/matplotlib/pbox.py

Added: branches/transforms/lib/matplotlib/pbox.py
===================================================================
--- branches/transforms/lib/matplotlib/pbox.py	                        (rev 0)
+++ branches/transforms/lib/matplotlib/pbox.py	2007-09-12 14:46:03 UTC (rev 3837)
@@ -0,0 +1,126 @@
+# MGDTODO: Just included verbatim for now
+
+class PBox(list):
+    '''
+    A left-bottom-width-height (lbwh) specification of a bounding box,
+    such as is used to specify the position of an Axes object within
+    a Figure.
+    It is a 4-element list with methods for changing the size, shape,
+    and position relative to its container.
+    '''
+    coefs = {'C':  (0.5, 0.5),
+             'SW': (0,0),
+             'S':  (0.5, 0),
+             'SE': (1.0, 0),
+             'E':  (1.0, 0.5),
+             'NE': (1.0, 1.0),
+             'N':  (0.5, 1.0),
+             'NW': (0, 1.0),
+             'W':  (0, 0.5)}
+    def __init__(self, box, container=None, llur=False):
+        if len(box) != 4:
+            raise ValueError("Argument must be iterable of length 4")
+        if llur:
+            box = [box[0], box[1], box[2]-box[0], box[3]-box[1]]
+        list.__init__(self, box)
+        self.set_container(container)
+
+    def as_llur(self):
+        return [self[0], self[1], self[0]+self[2], self[1]+self[3]]
+
+    def set_container(self, box=None):
+        if box is None:
+            box = self
+        if len(box) != 4:
+            raise ValueError("Argument must be iterable of length 4")
+        self._container = list(box)
+
+    def get_container(self, box):
+        return self._container
+
+    def anchor(self, c, container=None):
+        '''
+        Shift to position c within its container.
+
+        c can be a sequence (cx, cy) where cx, cy range from 0 to 1,
+        where 0 is left or bottom and 1 is right or top.
+
+        Alternatively, c can be a string: C for centered,
+        S for bottom-center, SE for bottom-left, E for left, etc.
+
+        Optional arg container is the lbwh box within which the
+        PBox is positioned; it defaults to the initial
+        PBox.
+        '''
+        if container is None:
+            container = self._container
+        l,b,w,h = container
+        if isinstance(c, str):
+            cx, cy = self.coefs[c]
+        else:
+            cx, cy = c
+        W,H = self[2:]
+        self[:2] = l + cx * (w-W), b + cy * (h-H)
+        return self
+
+    def shrink(self, mx, my):
+        '''
+        Shrink the box by mx in the x direction and my in the y direction.
+        The lower left corner of the box remains unchanged.
+        Normally mx and my will be <= 1, but this is not enforced.
+        '''
+        assert mx >= 0 and my >= 0
+        self[2:] = mx * self[2], my * self[3]
+        return self
+
+    def shrink_to_aspect(self, box_aspect, fig_aspect = 1):
+        '''
+        Shrink the box so that it is as large as it can be while
+        having the desired aspect ratio, box_aspect.
+        If the box coordinates are relative--that is, fractions of
+        a larger box such as a figure--then the physical aspect
+        ratio of that figure is specified with fig_aspect, so
+        that box_aspect can also be given as a ratio of the
+        absolute dimensions, not the relative dimensions.
+        '''
+        assert box_aspect > 0 and fig_aspect > 0
+        l,b,w,h = self._container
+        H = w * box_aspect/fig_aspect
+        if H <= h:
+            W = w
+        else:
+            W = h * fig_aspect/box_aspect
+            H = h
+        self[2:] = W,H
+        return self
+
+    def splitx(self, *args):
+        '''
+        e.g., PB.splitx(f1, f2, ...)
+
+        Returns a list of new PBoxes formed by
+        splitting the original one (PB) with vertical lines
+        at fractional positions f1, f2, ...
+        '''
+        boxes = []
+        xf = [0] + list(args) + [1]
+        l,b,w,h = self[:]
+        for xf0, xf1 in zip(xf[:-1], xf[1:]):
+            boxes.append(PBox([l+xf0*w, b, (xf1-xf0)*w, h]))
+        return boxes
+
+    def splity(self, *args):
+        '''
+        e.g., PB.splity(f1, f2, ...)
+
+        Returns a list of new PBoxes formed by
+        splitting the original one (PB) with horizontal lines
+        at fractional positions f1, f2, ..., with y measured
+        positive up.
+        '''
+        boxes = []
+        yf = [0] + list(args) + [1]
+        l,b,w,h = self[:]
+        for yf0, yf1 in zip(yf[:-1], yf[1:]):
+            boxes.append(PBox([l, b+yf0*h, w, (yf1-yf0)*h]))
+        return boxes


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