月度归档:2014年11月

Mathematica Table数据导出到文件如何自定义分隔符

解决百度知道问题:http://zhidao.baidu.com/question/1175318960009451299.html

原问题:
Mathematica 输出数据之间的长空格

代码如下,输出的数据之间空格太大太长,我只要一个小空格就可以了,怎么实现?

aaa = {{1, 2}, {3, 4}};
Export["C:\data\a1234.dat", aaa, "Table"];

 

解决方法加一个option, "FieldSeparators" -> "分隔符"
aaa = {{1, 2}, {3, 4}};
Export["d:\\a1234.dat", aaa, "Table", "FieldSeparators" -> " "];

参考:ref/format/Table(F1调出帮助,输入这个),帮助中还有很多可以修改的option 值得继续尝试。

 

Linux PPTP 连接数限制

Linux 搭建PPTP Server连接超过100个后,就再无法拨号成功了。

查看log 发现有以下信息:

# logread |grep -v "GRE"
Nov 20 11:17:13 pptpd[21132]: CTRL: Received PPTP Control Message (type: 5)
Nov 20 11:17:13 pptpd[21132]: CTRL: Made a ECHO RPLY packet
Nov 20 11:17:13 pptpd[21132]: CTRL: I wrote 20 bytes to the client.
Nov 20 11:17:13 pptpd[21132]: CTRL: Sent packet to client

 

#man pptpd.conf

connections n
	limits  the  number  of client connections that may be accepted.
	If pptpd is allocating IP addresses (e.g.  delegate is not used)
	then  the  number of connections is also limited by the remoteip
	option.  The default is 100.

 

PPTP Server 最大连接数,是connections和地址池数量一起控制的,connections默认是100,导致无法连接更多。
如果希望最大连接1000条,可以在pptpd.conf中添加一行配置(地址池要有1000个地址):
connections 1000