Hi,

I added a quick patch to allow numerical values for text alignment.
It now allows a number that is fraction of text hight or with and is measured relative to bottom or left. So
ha = 0 == 'left'
ha = 1 == 'right'
va = 0 == 'bottom'
va = 1 == 'top'
va/ha = 0.5 == 'center'

the cool thing is that values outside [0,1] allow you to some defined distance from a line or symbol that remains well-measured even if you interactively scale the figure.

Can you please add this to MPL?

(also fixed some typos in typo doc)

This is my first addition here, not sure how to add patches, I can submit a pull request it appears.

-Alexander

2sn/matplotlib@master...text-numeric-va-ha

From b167849f438e4b77319c51fd603946525823edc0 Mon Sep 17 00:00:00 2001
From: Alexander Heger [email protected]
Date: Fri, 31 Aug 2012 16:58:04 +1000
Subject: [PATCH 1/2] ADD - added numeric update for ha and va in Text

lib/matplotlib/text.py | 34 +++++++++++++++++++---------------
1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/lib/matplotlib/text.py b/lib/matplotlib/text.py
index b00e4cf..b1188de 100644
--- a/lib/matplotlib/text.py
+++ b/lib/matplotlib/text.py
@@ -10,7 +10,7 @@ from matplotlib import cbook
from matplotlib import rcParams
import matplotlib.artist as artist
from matplotlib.artist import Artist
-from matplotlib.cbook import is_string_like, maxdict
+from matplotlib.cbook import is_string_like, maxdict, is_numlike
from matplotlib import docstring
from matplotlib.font_manager import FontProperties
from matplotlib.patches import bbox_artist, YAArrow, FancyBboxPatch,
@@ -69,21 +69,21 @@ docstring.interpd.update(Text = """
family [ 'serif' | 'sans-serif' | 'cursive' | 'fantasy' | 'monospace' ]
figure a matplotlib.figure.Figure instance
fontproperties a matplotlib.font_manager.FontProperties instance

• horizontalalignment or ha [ 'center' | 'right' | 'left' ]

• horizontalalignment or ha [ 'center' | 'right' | 'left' | fraction text width from left ]
  label any string
  linespacing float
  lod [True | False]
  multialignment ['left' | 'right' | 'center' ]
  name or fontname string eg, ['Sans' | 'Courier' | 'Helvetica' ...]
  position (x,y)

• rotation [ angle in degrees 'vertical' | 'horizontal'

• rotation [ angle in degrees | 'vertical' | 'horizontal' ]
  rotation_mode [ None | 'anchor']
  size or fontsize [ size in points | relative size eg 'smaller', 'x-large' ]
  style or fontstyle [ 'normal' | 'italic' | 'oblique']
  text string
  transform a matplotlib.transform transformation instance
  variant [ 'normal' | 'small-caps' ]

• verticalalignment or va [ 'center' | 'top' | 'bottom' | 'baseline' ]

• verticalalignment or va [ 'center' | 'top' | 'bottom' | 'baseline' | fraction text height from bottom ]
  visible [True | False]
  weight or fontweight [ 'normal' | 'bold' | 'heavy' | 'light' | 'ultrabold' | 'ultralight']
  x float
  @@ -378,25 +378,29 @@ class Text(Artist):
  if rotation_mode != "anchor":
  # compute the text location in display coords and the offsets
  # necessary to align the bbox with that location

•        if halign=='center':  offsetx = (xmin + width/2.0)
  

•        if halign=='center':  offsetx = (xmin + width*0.5)
       elif halign=='right': offsetx = (xmin + width)
  

•        elif is_numlike(halign): offsetx = xmin + halign * (xmax - xmin)
       else: offsetx = xmin
  

•        if valign=='center': offsety = (ymin + height/2.0)
  

•        if valign=='center': offsety = (ymin + height*0.5)
       elif valign=='top': offsety  = (ymin + height)
       elif valign=='baseline': offsety = (ymin + height) - baseline
  

•        elif is_numlike(valign): offsety = ymin + valign * (ymax - ymin)
       else: offsety = ymin
   else:
       xmin1, ymin1 = cornersHoriz[0]
       xmax1, ymax1 = cornersHoriz[2]
  

•        if halign=='center':  offsetx = (xmin1 + xmax1)/2.0
  

•        if halign=='center':  offsetx = (xmin1 + xmax1)*0.5
       elif halign=='right': offsetx = xmax1
  

•        elif is_numlike(halign): offsetx = xmin1 + halign * (xmax1 - xmin1)
       else: offsetx = xmin1
  

•        if valign=='center': offsety = (ymin1 + ymax1)/2.0
  

•        if valign=='center': offsety = (ymin1 + ymax1)*0.5
       elif valign=='top': offsety  = ymax1
       elif valign=='baseline': offsety = ymax1 - baseline
  

•        elif is_numlike(valign): offsety = ymin1 + valign * (ymax1 - ymin1)
       else: offsety = ymin1
  
       offsetx, offsety = M.transform_point((offsetx, offsety))
  

  @@ -796,11 +800,11 @@ class Text(Artist):
  """
  Set the horizontal alignment to one of

•    ACCEPTS: [ 'center' | 'right' | 'left' ]
  

•    ACCEPTS: [ 'center' | 'right' | 'left' | fraction text width from left ]
   """
   legal = ('center', 'right', 'left')
  

•    if align not in legal:
  

•        raise ValueError('Horizontal alignment must be one of %s' % str(legal))
  

•    if align not in legal and not is_numlike(align):
  

•        raise ValueError('Horizontal alignment must be numeric or one of %s' % str(legal))
   self._horizontalalignment = align
  

  def set_ma(self, align):
  @@ -811,7 +815,7 @@ class Text(Artist):
  def set_multialignment(self, align):
  """
  Set the alignment for multiple lines layout. The layout of the

•    bounding box of all the lines is determined bu the horizontalalignment
  

•    bounding box of all the lines is determined but the horizontalalignment
   and verticalalignment properties, but the multiline text within that
   box can be
  

@@ -957,11 +961,11 @@ class Text(Artist):
"""
Set the vertical alignment

•    ACCEPTS: [ 'center' | 'top' | 'bottom' | 'baseline' ]
  

•    ACCEPTS: [ 'center' | 'top' | 'bottom' | 'baseline' | fraction text height from bottom ]
   """
   legal = ('top', 'bottom', 'center', 'baseline')
  

•    if align not in legal:
  

•        raise ValueError('Vertical alignment must be one of %s' % str(legal))
  

•    if align not in legal and not is_numlike(align):
  

•        raise ValueError('Vertical alignment must be numeric or one of %s' % str(legal))
  
   self._verticalalignment = align
  

1.7.11.4

From 076d2ef17d8bb25417ee805a9b9a9221918d230f Mon Sep 17 00:00:00 2001
From: Alexander Heger [email protected]
Date: Fri, 31 Aug 2012 17:05:23 +1000
Subject: [PATCH 2/2] BF typo

lib/matplotlib/text.py | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/matplotlib/text.py b/lib/matplotlib/text.py
index b1188de..a22dd64 100644
--- a/lib/matplotlib/text.py
+++ b/lib/matplotlib/text.py
@@ -815,7 +815,7 @@ class Text(Artist):
def set_multialignment(self, align):
"""
Set the alignment for multiple lines layout. The layout of the

•    bounding box of all the lines is determined but the horizontalalignment
  

•    bounding box of all the lines is determined by the horizontalalignment
   and verticalalignment properties, but the multiline text within that
   box can be
  

1.7.11.4