Saturday 8 March 2014

Reproducing Kernel Hilbert Spaces

I was recently recommended a paper to read: From Zero to Reproducing Kernal Hilbert Spaces in Twelve Pages or Less.

This is a post about me trying to understand the contents of this paper and will be updated as i go through it. I hope this may help someone else eventually.

Up until page 6 i found it quite straight forward i will not write anything about this as i believe the paper would explain it better than i could. The concept of norms with higher powers (the p norm) is straight forward. It is easily seen in the 4.3 Examples from the definition in R^n.

The lp space eq1 in section 4.3.1 is just saying all xi elements which are finite. Ie) Infinite elements are not allowed. Then the lp norm is defined in eq2 in this section.

As a summary so far:
Banach Spaces = Vector Spaces with a definition of the norm or 'length'
Hilbert Spaces = Banach Space with a definition of the dot product


Thursday 6 February 2014

Get info about connected processes

This is a little script i wrote to see all tcp/udp connections and see what they are

#! /bin/bash

tcpports=$(netstat -ano | grep tcp | grep -E -o ":[0-9]+" | grep -E -o "[0-9]+")
udpports=$(netstat -ano | grep udp | grep -E -o ":[0-9]+" | grep -E -o "[0-9]+")
for p in $tcpports
do
    pid=$(sudo fuser $p/tcp 2>/dev/null | grep -E -o "[0-9]+")
if [ "$pid" ]
then
    name=$(ps -eo comm,pid | grep $pid | egrep -o '^[^0-9]+')
echo $name ' with pid ' $pid ' is on ' $p
whatis $name
fi
done
for p in $udpports
do
    pid=$(sudo fuser $p/udp 2>/dev/null | grep -E -o "[0-9]+")
if [ "$pid" ]
then
    name=$(ps -eo comm,pid | grep $pid | egrep -o '^[^0-9]+')
echo $name ' with pid ' $pid ' is on ' $p
whatis $name
fi
done