Chinese character display with VPtyhon
VPython到底能不能显示中文字符?能显示哪些中文字体?下面的code给出答案。
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VPython到底能不能显示中文字符?能显示哪些中文字体?下面的code给出答案。
Continue reading ‘Chinese character display with VPtyhon’ »

目前全球有约10亿台计算机,每台按100Wh实际功率计算,总功率为1亿千瓦时。也就是说每小时耗电量为1亿千瓦。按计算机一天工作10小时计算,一天全球消耗总电量为10亿千瓦时。世界超大型水电站(如三峡电站)在汛期全部机组开动发电量不过4亿千瓦时(参见)。意味着我们需要2-3个这样的超大水电站全负荷供电才能满足基本需求。我们知道,建设一个这样的电站要耗费数以亿计的金钱和数十年的人工。但是,如果作为程序员,往往可以轻易地提高编码质量和运行效率以达到节省计算时间的目的,变相地节约了宝贵的能源,有利于保护地球环境。我觉得如果所有程序员都朝这个方向努力,每天节省一个三峡电站的电量是完全可能的。
1. apt-get install mpich2 (remove other implementation to prevent trouble)
2. create .mpd.conf file under home dir ~/ , add a line “password=qwert” (replace qwert with any other texts)
3. create a hostfile or machine file (e.g. mpd.hosts) with node names listed one per line. (this file can be in any folder)
4. start mpd. There is a script shipped with mpich2 “mpdboot”. It accept some options. “mpdboot -f mpd.hosts -n #” with #<= number of nodes listed in mpd.hosts file. This command will start mpd on all the nodes if ssh or rsh is set correctly (without password).
5 use mpdtrace to verify the node names (nodes having been added to the mpd ring, ready to be used in the following mpirun calls).
6 mpirun -np N -host node1,node2 ./program (it’s not necessary to use all the nodes in the ring, but some of them is fine)
By default Notepad2 add a .txt extension to the file name when you save a newly created file. For files already having extensions, this will not be done. However, this is sometimes annoying if you often create files which do not use txt as extension although they are actually plain text files. I think this is almost a daily work for programmers. To cancel this feature, there are two ways. First, when you save the newly created file, simply add quote symbols around the file name like “new_file”, then the file will be save without an extension or with any extension you give. This trick also works for the Windows Notepad program. Another hack is to modify notepad2.ini, there you can create a new section (if it’s not there already) named “[settings2]“. The settings given in this section will override the default behavior. Then add an entry “DefaultExtension=”, yeah just leave nothing behind the equal sign, no suffix will be appended automatically then. There are more options for the customized section, see here.
经常在C++程序中加入中文注释,但是如果使用不同的编辑器,编码识别或转换不当,会导致非ASCII字符乱码。
VS中编译有时很费时间,如果有声音提示编译结果会比较方便,这样就不用总是查看输出窗口了。根据这篇文章,VS声音提示并不在VS软件设置中,而是在系统的“控制面板”中。打开“声音和音频设备”点击“声音”选项卡,在“程序事件”列表下找到“Microsoft Visual Studio”,就可以为编译成功、编译失败和取消编译等事件指定声音了。
某些VS的Addins会导致程序异常缓慢或出错,一个小技巧是在启动VS的时候提前按住左边的shift键,即可禁止加载所有插件。
Python的distutils可以很方便地制作模块安装程序,但是没有提供反安装/卸载功能。