VNC over SSH

VNC over SSH is one of the secure ways to remotely access computer desktop.

At the server side (the remote computer which you want to log to):
vncserver :64 -geometry 1024x768 -depth 16 -name user

At the viewer side (the local computer you are using now):
vncviewer -via 192.168.1.2 localhost:64

192.168.1.2 is the server' IP.

After you finish, kill the process at server:
vncserver -kill :64

ssh -X command

Log in a computer as
ssh -X user@sever
One can use some command to get GUI work. Such as:

firefox & (which can view files by enter file:///home/user)
nautilus &
konqueor &

Gnuplot (plot part of data file)

A good reference website: http://t16web.lanl.gov/Kawano/gnuplot/datafile2-e.html

To specify a range of the data to be plotted, use the every option in the plot command. To skip every two lines, say plot "test.dat" every 2

.

When the data file contains several data blocks those are separated by a single blank line, you can skip the data block by the every option. To skip every two block, try plot "test.dat" every :2

.

every I:J:K:L:M:N	I Line increment J Data block increment K The first line L The first data block M The last line N The last data block
every 2	plot every 2 line
every ::3	skip the first 3 lines
every ::3::5	plot from the 4-th to 6-th lines
every ::0::0	plot the first line only
every 2::::6	plot the 1,3,5,7-th lines
every :2	plot every 2 data block
every :::5::8	plot from 5-th to 8-th data blocks

Alternatively (if you are on the UNIX-like system), a part of your data file can be plotted by using the unix commands, "head" and "tail".

Questions

1. What are laser modes (longitudinal and transverse)?
   
2. Simple question, can I see them? --show me!
   
3. Where do they come from? where do they go? why do we care about them? what can we benefit from understanding the laser mode dynamics?
4. Another straight question, can I manipulate laser modes (longitudinal and transverse)? if yes, how?
5. What are origins of laser modes (longitudinal and transverse)? --in details!
   
6. How do they develop from noise? --in details