在mac os上使用octave绘图时发现：
dyld: Library not loaded: /usr/X11/lib/libfreetype.6.dylib出错信息类似：
dyld: Library not loaded: /usr/X11/lib/libfreetype.6.dylib
Referenced from: /usr/X11R6/lib/libfontconfig.1.dylib
Reason: Incompatible library version: libfontconfig.1.dylib requires version 13.0.0 or later, but libfreetype.6.dylib provides version 10.0.0
dyld: Library not loaded: /usr/X11/lib/libfreetype.6.dylib
Referenced from: /usr/X11R6/lib/libfontconfig.1.dylib
Reason: Incompatible library version: libfontconfig.1.dylib requires version 13.0.0 or later, but libfreetype.6.dylib provides version 10.0.0
/Applications/Gnuplot.app/Contents/Resources/bin/gnuplot: line 71: 865 Trace/BPT trap GNUTERM="${GNUTERM}" GNUPLOT_HOME="${GNUPLOT_HOME}" PATH="${PATH}" DYLD_LIBRARY_PATH="${DYLD_LIBRARY_PATH}" HOME="${HOME}" GNUHELP="${GNUHELP}" DYLD_FRAMEWORK_PATH="${DYLD_FRAMEWORK_PATH}" GNUPLOT_PS_DIR="${GNUPLOT_PS_DIR}" DISPLAY="${DISPLAY}" GNUPLOT_DRIVER_DIR="${GNUPLOT_DRIVER_DIR}" "${ROOT}/bin/gnuplot-4.2.6" "$@"
/Applications/Gnuplot.app/Contents/Resources/bin/gnuplot: line 71: 871 Trace/BPT trap GNUTERM="${GNUTERM}" GNUPLOT_HOME="${GNUPLOT_HOME}" PATH="${PATH}" DYLD_LIBRARY_PATH="${DYLD_LIBRARY_PATH}" HOME="${HOME}" GNUHELP="${GNUHELP}" DYLD_FRAMEWORK_PATH="${DYLD_FRAMEWORK_PATH}" GNUPLOT_PS_DIR="${GNUPLOT_PS_DIR}" DISPLAY="${DISPLAY}" GNUPLOT_DRIVER_DIR="${GNUPLOT_DRIVER_DIR}" "${ROOT}/bin/gnuplot-4.2.6" "$@"
error: you must have gnuplot installed to display graphics; if you have gnuplot installed in a non-standard location, see the 'gnuplot_binary' function
解决方案在http://stackoverflow.com/questions/4175411/plotting-with-octave-after-most-recent-mac-osx-update 上找到
在mac os的以下文件中
/Applications/Gnuplot.app/Contents/Resources/bin/gnuplot
找到DYLD_LIBRARY_PATH替换为DYLD_FALLBACK_LIBRARY_PATH，一共有4处，全部替换。
然后OK。