zsh: jekyll command not found

重启系统后,运行jekyll命令显示

jekyll: commmand not found

使用如下命令解决问题:
echo "source $HOME/.rvm/scripts/rvm" >> ~/.bash_profile

参考:http://stackoverflow.com/questions/15409418/after-installing-jekyll-getting-bash-jekyll-command-not-found

ubuntu 12.40 安装jekyll

先安装rvm

curl -L https://get.rvm.io | bash -s stable --ruby
source ~/.rvm/scripts/rvm
rvm install 1.9.3
rvm use 1.9.3
rvm rubygems latest

然后替换 RubyGems 的到淘宝镜像:

gem sources --remove https://rubygems.org/
gem sources -a http://ruby.taobao.org/
gem sources -l

然后安装jekyll,在安装jekyll前先安装rdoc,否则会失败,

gem install rdoc
gem install jekyll

安装完毕

参考:
1.http://ruby-china.org/wiki/install-rails-on-ubuntu-12-04-server

java.lang.IllegalStateException: Cannot forward after response has been committed in servlet 错误

写jsp程序时遇到这个错误,一般错误的原因是sendredirect后没有返回

protected void doPost() {
    if (someCondition) {
        sendRedirect();
    }
    forward(); // This is STILL invoked when someCondition is true!
}

解决方法是加一个return或加一个else分支:

protected void doPost() {
    if (someCondition) {
        sendRedirect();
        return;
    }
    forward();
}

或

protected void doPost() {
    if (someCondition) {
        sendRedirect();
    }else{
    forward(); 
}
}

但是我的代码中sendRedirect是最后一句代码,后面跟着return,居然还有这个运行错误.

原因在于jsp中response具有缓存大小的限制,如果达到这个限制,那么所有HTTP response headers和写入的html代码都会发送回客户端,也就是response is committed.虽然你没有显式指定返回.

检查了一下我的代码,原来我为了测试用如下代码向response写入了很多单词:

  PrintWriter out = response.getWriter();
  
  for( String str: result )
   out.print(str + " ");
  out.println(result.size());
  out.close();

注释掉这段代码之后就可以正常运行了.

参考:
1.http://stackoverflow.com/questions/2123514/java-lang-illegalstateexception-cannot-forward-after-response-has-been-committe/2125045#2125045
2.http://stackoverflow.com/questions/12693975/java-lang-illegalstateexception-cannot-call-sendredirect-after-the-response-h

ubuntu12.04 安装 texlive和texstudio

二者都是从ppa安装,因为源里面版本可能会旧一些.

sudo add-apt-repository ppa:texlive-backports/ppa
sudo add-apt-repository ppa:blahota/texstudio
sudo apt-get update
sudo apt-get install texlive-xetex texstudio

安装时间挺长,耐心等待.

安装完后,我还安装了几个包,如下:

sudo apt-get install texlive-fonts-recommended         
sudo apt-get install texlive-lang-cjk         

这两个包是和中文,字体相关的,没装之前编译tex文件会出错,装了之和就没问题了.

最后,安装了苹果下面的"Hiragino Sans GB" 字体

下载之后,如下操作:

sudo mkdir /usr/share/fonts/applefonts
sudo chmod 777 /usr/share/fonts/applefonts
sudo mkfontscale 　　　　
sudo mkfontdir 　　　　
sudo fc-cache -fsv 

ok了.
参考:
1.https://launchpad.net/~blahota/+archive/texstudio/
2.https://launchpad.net/~texlive-backports/+archive/ppa
3.http://lzuzyy.blog.ubuntu.org.cn/content/texlive2012texstudio%EF%BC%88texmaker252%EF%BC%89%E7%9A%84%E4%B8%AD%E6%96%87%E9%85%8D%E7%BD%AE

ubuntu12.04 安装grive

grive是google drive的linux客户端,安装过程如下:

sudo add-apt-repository ppa:nilarimogard/webupd8
sudo apt-get update
sudo apt-get install grive

然后,创建一个用于存放网盘文件的文件夹,假设为a,

mkdir a
cd a
sudo grive -a#不加sudo的话,我这里会出现错误.

第一次使用grive时需要grive命令中的-a选项获得google drive的权限.
打开终端现实的链接,选择allow,复制验证码到终端中,grive会自动同步网盘中的文件.

以后想同步的话就在终端切换到网盘目录,然后执行

sudo grive

ps:我第一次同步后发现所有文件权限都不够,直接修改如下:

sudo chmod -R 777 *

参考:http://www.webupd8.org/2012/05/grive-open-source-google-drive-client.html

ubuntu12.04 安装stardict

从ubuntu源里安装的版本较早,所以下载安装文件安装,下载地址:https://code.google.com/p/stardict-3/.

安装后下载词典,下载地址:https://code.google.com/p/stardict-3/wiki/DownloadDictionaries.
下载后解压到/usr/share/stardict/dict目录下,重启stardict.

(转)把mat文件保存为txt格式而不损失精度

Subject:

How can I avoid truncation and loss of precision when saving my data in MATLAB?

Problem Description:

I have tried saving my data with SAVE -ASCII (or FPRINTF, DLMWRITE, etc.) and notice that I lose precision when I do this.

Solution:

To obtain 16-digit ASCII format using the SAVE function, use the following command:
save -ascii -double Following is an example of writing "pi" to a TXT-file with double precision using DLMWRITE:
dlmwrite('myfile1.txt', pi, 'delimiter', '\t', 'precision', 16)
For more information on precision specification, refer the respective documentation pages by executing the following MATLAB commands:
doc save
doc dlmwrite
Information on C-style format string allowed in DLMWRITE can be found here:
doc sprintf

参考:
 http://www.mathworks.cn/support/solutions/en/data/1-1CBW5/?product=SL&solution=1-1CBW5