matplotlib-users Mailing List for matplotlib

Hello,
I am trying to build matplotlib from source on CentOS. I have installed all
the dependencies, including numpy, freetype, libpng, etc. I also have both
the C and C++ compiler (gcc and cgg-c++) installed in /usr/lib/. However
when running python setup.py install I get the following error message:
pymods ['pylab']
packages ['matplotlib', 'matplotlib.backends',
'matplotlib.backends.qt4_editor', 'matplotlib.projections',
'matplotlib.testing', 'matplotlib.testing.jpl_units', 'matplotlib.tests',
'mpl_toolkits', 'mpl_toolkits.mplot3d', 'mpl_toolkits.axes_grid',
'mpl_toolkits.axes_grid1', 'mpl_toolkits.axisartist',
'matplotlib.sphinxext', 'matplotlib.tri', 'matplotlib.delaunay', 'pytz',
'dateutil', 'dateutil.zoneinfo']
running install
running build
running build_py
copying lib/matplotlib/mpl-data/matplotlibrc ->
build/lib.linux-x86_64-2.4/matplotlib/mpl-data
copying lib/matplotlib/mpl-data/matplotlib.conf ->
build/lib.linux-x86_64-2.4/matplotlib/mpl-data
running build_ext
building 'matplotlib.ft2font' extension
c++ -pthread -shared build/temp.linux-x86_64-2.4/src/ft2font.o
build/temp.linux-x86_64-2.4/src/mplutils.o
build/temp.linux-x86_64-2.4/CXX/IndirectPythonInterface.o
build/temp.linux-x86_64-2.4/CXX/cxxsupport.o
build/temp.linux-x86_64-2.4/CXX/cxx_extensions.o
build/temp.linux-x86_64-2.4/CXX/cxxextensions.o -L/usr/local/lib -L/usr/lib
-L/usr/local/lib64 -L/usr/lib64 -lfreetype -lz -lstdc++ -lm -o
build/lib.linux-x86_64-2.4/matplotlib/ft2font.so
/usr/bin/ld: cannot find -lz
collect2: ld returned 1 exit status
error: command 'c++' failed with exit status 1
I have scoured the web with no solution. Please HELP!
Thanks,
-- 
Amanda Stott

On Tue, May 29, 2012 at 5:31 AM, Yasin Selçuk Berber
<yas...@gm...>wrote:
>
> Hi. I want to make sure how imshow shows a numpy array as image.
>
> lets say below is our numpy data array where letter represent data values
> and numbers represent row/col indices.
>
> 0 1 2
> 0 a b c
> 1 d e f
> 2 g h i
>
> and lets think imshow's origin is default upper left.
> Now, if we show our data as an image, the orientation of visual
> representation of data shouldt change,
> and seen like below, right?
>
> 0 1 2
> 0 a b c
> 1 d e f
> 2 g h i
>
> But if we pass origin="lower" keyword to imshow, (as in basemap by
> default);
> is this what we expect to see ?
>
> 0 1 2
> 2 g h i
> 1 d e f
> 0 a b c
>
> To be clear, does imshow with "lower" keyword value;
>
> 1-takes first row of data and put it most bottom,
> 2-then take second row and put it one row upper from most bottom.....etc ?
>
> Thanks.
>
> --
> Yasin Selçuk Berber
> "Bismillah, her hayrın başıdır."
>
>
Hi Yasin,
Yes, your interpretation looks correct to me. Image coordinates typically
have an origin at the upper left and increase downward and to the right.
Setting `origin='lower' ` essentially changes `imshow` to use data
coordinates, which typically have an origin at the bottom left and increase
upward and to the right.
Do you expect (or get) something different?
Best,
-Tony