Substringing in matlab

Many functions in matlab let you do various things to strings

strtok(s,delim)
returns the substring before delim

[first,rem]=strtok(s,delim)
first the substring before delim
rem the substring s-first(it includes delim)

strrep(s,'a','b')
replaces a with b in s

a script for counting images/features

for i in $(ls);
 do
cd $i;
imcount=`ls |wc -l`;
cd /home/nchavali/feature_extraction/SUN_source_code_v2/data/ImagenetDataset/feature/$i;
for j in $(ls);
do
cd $j;
fcount=`ls|wc -l`;
if [ "$imcount" -ne "$fcount" ]; then
echo $i;
echo $imcount
echo $j;
echo $fcount;
fi
cd /home/nchavali/feature_extraction/SUN_source_code_v2/data/ImagenetDataset/feature/$i;
done

cd /home/nchavali/feature_extraction/SUN_source_code_v2/data/ImagenetDataset/image;
done

Some file operations in unix

 for i in $(ls); do h=`echo $i|cut -d '_' -f1`; echo $h; done

This lists all the files in the current dir, and ehos a part of their name. thsi h can then be used as a directory location

Latex homework Q/A template

\documentclass{article}
\usepackage{lipsum}
\newcounter{question}
\setcounter{question}{0}
\begin{document}

\title{ ECE 5605 Stochastic Signals and Systems, Fall 2013 \\Homework 1}%replace X with the appropriate number
\author{Neelima Chavali \\ PID 905774330 %replace with your name
} %if necessary, replace with your course title
\maketitle

\newcommand\Que[1]{%
   \leavevmode\par
   \stepcounter{question}
   \noindent
   \thequestion. Q --- #1\par}

\newcommand\Ans[2][]{%
    \leavevmode\par\noindent
   {\leftskip1    pt
    A. --- \textbf{#1} #2\par}}

\Que{
{2.21} %You can use theorem, exercise, problem, or question here. Modify x.yz to be whatever number you are proving
A die is tossed and the number of dots facing up is noted.\\ (a)Find the probability of the elementary events under the assumption that all faces of
the die are equally likely to be facing up after a toss.
}
\Ans{
The elementary events in this case are the face of the die showing a specific number of dots facing up. The number of elementary events (= 6) is finite. And it is given that all the elementary events are equally likely. Then the classical definiton of probability can be used to derive the probability of the elementary events. There are 6 mutually exclusive elementary outcomes.(1,2,..,6 dots facing up). The attribute A=i dots facing up, i=1,2,..,6 has one elementary event associated with it. $n_{A}=1$ for for all A. Therefore the probability of the elementary events is $n_{A}/n$ = 1/6
}

\end{document}

\Que{Here first question would come}
\Ans{\lipsum[1]\lipsum[1]}

\Que{Here first question would come}
\Ans{\lipsum[1]\lipsum[1]}