Merge lp:~kolmis/cairoplot/speedup into lp:cairoplot

[Karel Kolman]

[Karel Kolman (kolmis)]

Hi, i'm experimenting with using cairoplot to render plots in the wxbanker project and i stumbled upon some performance related problems which lead me to examining cairoplot's code. Summary of changes proposed in this branch:

 - speed up x_labels rendering
 +++ (create the rotation matrix once only, apply it for each x_label - this is a major improvement)

 - added a timer.sh script and a test plot with 1000 x_labels to show the performance difference

 - replace rotate(angle), rotate(-angle) pairs with save(), rotate(angle), restore() triples
 +++ (i have absolutely none experience in graphics programming, but i think this is the way to go, since i'd say these two rotations added don't have to result in an identity matrix due to floating number arithmetics and rounding errors)

 - added a script for visual comparison of outputs, it diffs two outputs from seriestests.py and creates diff images in PPM format
 +++ i performed the following test: i created two cairoplot versions:
 ====== 1. all show_text() references removed, the rotate(angle), rotate(-angle) statements stayed
 ====== 2. all show_text() references removed, all rotate() pairs removed
 ====== comparing these two some plots were different whereas they should be exactly the same

[Karel Kolman (kolmis)]

and i meant a minor improvement, not major :)

[Rodrigo Moreira Araújo (alf-rodrigo)]

Hello Karel,

I'm sorry for the long time, but I'd like to let you know I just merged your
code onto the main branch.

Thanks a lot for the contribution.

Cheers,

Rodrigo Araujo

On Wed, Oct 7, 2009 at 7:07 AM, Karel Kolman <email address hidden> wrote:

> and i meant a minor improvement, not major :)
> --
> https://code.launchpad.net/~kolmis/cairoplot/speedup/+merge/12980
> You are requested to review the proposed merge of
> lp:~kolmis/cairoplot/speedup into lp:cairoplot.
>

[Karel Kolman (kolmis)]

Thanks for merging the branch.

=== modified file 'trunk/cairoplot.py'
--- trunk/cairoplot.py	2009-07-09 21:57:24 +0000
+++ trunk/cairoplot.py	2009-10-07 10:00:26 +0000
@@ -510,9 +510,10 @@
         if self.titles[VERT]:
             title_width,title_height = cr.text_extents(self.titles[VERT])[2:4]
             cr.move_to( self.dimensions[HORZ] - self.borders[HORZ] + title_height/2, self.dimensions[VERT]/2 - title_width/2)
+            cr.save()
             cr.rotate( math.pi/2 )
             cr.show_text( self.titles[VERT] )
-            cr.rotate( -math.pi/2 )
+            cr.restore()
         
     def render_grid(self):
         cr = self.context
@@ -544,21 +545,29 @@
         cr = self.context
         step = float( self.plot_width ) / ( len( self.labels[HORZ] ) - 1 )
         x = self.borders[HORZ]
+        y = self.dimensions[VERT] - self.borders[VERT] + 5
+        
+        # store rotation matrix from the initial state
+        rotation_matrix = cr.get_matrix()
+        rotation_matrix.rotate(self.x_label_angle)
+
+        cr.set_source_rgba(*self.label_color)
+
         for item in self.labels[HORZ]:
-            cr.set_source_rgba(*self.label_color)
             width = cr.text_extents(item)[2]
-            cr.move_to(x, self.dimensions[VERT] - self.borders[VERT] + 5)
-            cr.rotate(self.x_label_angle)
+            cr.move_to(x, y)
+            cr.save()
+            cr.set_matrix(rotation_matrix)
             cr.show_text(item)
-            cr.rotate(-self.x_label_angle)
+            cr.restore()
             x += step
     
     def render_vert_labels(self):
         cr = self.context
         step = ( self.plot_height ) / ( len( self.labels[VERT] ) - 1 )
         y = self.plot_top
+        cr.set_source_rgba(*self.label_color)
         for item in self.labels[VERT]:
-            cr.set_source_rgba(*self.label_color)
             width = cr.text_extents(item)[2]
             cr.move_to(self.borders[HORZ] - width - 5,y)
             cr.show_text(item)
 
=== modified file 'trunk/seriestests.py'
--- trunk/seriestests.py	2009-07-09 21:57:24 +0000
+++ trunk/seriestests.py	2009-10-07 10:00:26 +0000
@@ -1,8 +1,16 @@
-import cairo, math, random
+import cairo, math, sys
 
 import cairoplot
 from series import Series
 
+# non-random data for needs of visual comparison of changes
+if '--non-random' in sys.argv:
+    random = lambda : 1.0
+    print 'Plotting nonrandom data'
+else:
+    import random
+    random = random.random
+
 # Line plotting
 test_scatter_plot = 1
 test_dot_line_plot = 1
@@ -48,8 +56,8 @@
     f = [math.exp(x) for x in t]
     g = [10*math.cos(x) for x in t]
     h = [10*math.sin(x) for x in t]
-    erx = [0.1*random.random() for x in t]
-    ery = [5*random.random() for x in t]
+    erx = [0.1*random() for x in t]
+    ery = [5*random() for x in t]
     data = Series({"exp" : [t,f], "cos" : [t,g], "sin" : [t,h]})
     series_colors = [ (1,0,0), (0,0,0), (0,0,1) ]
     cairoplot.scatter_plot ( 'cross_r_exponential_series.png', data = data, errorx = [erx,erx], errory = [ery,ery], width = 800, height = 600, border = 20, 
@@ -77,6 +85,12 @@
     cairoplot.dot_line_plot( 'dot_line_3_series_legend_series.png', data, 400, 300, x_labels = x_labels, 
                              axis = True, grid = True, series_legend = True )
 
+    #Speed test, many x_labels
+    data = range(1000)
+    x_labels = [str(x) for x in data]
+    cairoplot.dot_line_plot( 'dot_line_4_many_x_labels.png', data, 14000, 300, x_labels = x_labels, 
+                             axis = True, grid = True, series_legend = True )
+
 if test_function_plot :
     #Default Plot
     data = lambda x : x**2
@@ -142,7 +156,7 @@
     cairoplot.vertical_bar_plot ( 'vbar_8_hy_labels_series.png', data, 600, 200, border = 20, display_values = True, grid = True, x_labels = x_labels, y_labels = y_labels )
     
     #Large data set
-    data = Series([[10*random.random()] for x in range(50)])
+    data = Series([[10*random()] for x in range(50)])
     x_labels = ["large label name oh my god it's big" for x in data]
     cairoplot.vertical_bar_plot ( 'vbar_9_large_series.png', data, 1000, 800, border = 20, grid = True, rounded_corners = True, x_labels = x_labels )
     
@@ -182,7 +196,7 @@
     cairoplot.horizontal_bar_plot ( 'hbar_8_hy_labels_series.png', data, 600, 200, border = 20, series_labels = series_labels, display_values = True, grid = True, x_labels = x_labels, y_labels = y_labels )
 
     #Large data set
-    data = Series([[10*random.random()] for x in range(25)])
+    data = Series([[10*random()] for x in range(25)])
     x_labels = ["large label name oh my god it's big" for x in data]
     cairoplot.horizontal_bar_plot ( 'hbar_9_large_series.png', data, 1000, 800, border = 20, grid = True, rounded_corners = True, x_labels = x_labels )
 
@@ -242,8 +256,8 @@
     f = [math.exp(x) for x in t]
     g = [10*math.cos(x) for x in t]
     h = [10*math.sin(x) for x in t]
-    erx = [0.1*random.random() for x in t]
-    ery = [5*random.random() for x in t]
+    erx = [0.1*random() for x in t]
+    ery = [5*random() for x in t]
     data = Series({"exp" : [t,f], "cos" : [t,g], "sin" : [t,h]})
     series_colors = [ (1,0,0), (0,0,0) ]
     cairoplot.scatter_plot ( 'scatter_color_themes_series.png', data = data, errorx = [erx,erx], errory = [ery,ery], width = 800, height = 600, border = 20, 
 
=== added directory 'trunk/testscripts'
=== added file 'trunk/testscripts/compare.sh'
--- trunk/testscripts/compare.sh	1970-01-01 00:00:00 +0000
+++ trunk/testscripts/compare.sh	2009-10-07 10:00:26 +0000
@@ -0,0 +1,22 @@
+#!/bin/sh
+
+if [ $# -ne 3 ]
+then
+    echo "Compare .png files in two directories"
+    echo "Usage: ./compare.sh path1 path2 diffdir"
+    echo "Example: ./compare.sh . ../other ./diff"
+    exit
+fi
+
+for dir in $1 $2
+do
+  for i in $dir/*.png
+  do
+    convert $i $i.tiff
+  done
+done
+
+for i in `(cd $1; ls *.tiff)`
+do
+    perceptualdiff $1/$i $2/$i -output $3/$i.ppm
+done
 
=== added file 'trunk/testscripts/timeit.sh'
--- trunk/testscripts/timeit.sh	1970-01-01 00:00:00 +0000
+++ trunk/testscripts/timeit.sh	2009-10-07 10:00:26 +0000
@@ -0,0 +1,3 @@
+#!/bin/sh
+DIRNAME=`dirname $0`
+(cd $DIRNAME/..; python -m timeit -n 1 -v "import seriestests")