F.Session3

In this session I've studied sections 3 and 4 of MATLAB-jahad. Main ideas in these sections are explained below: f
1. Solving a series of equations by matrices in MATLAB: We can solve equations easily by two matrices in MATLAB, one is coefficients matrix and another is the known numbers (numbers on the right side of every equation). Even we can solve equations which number of their unknown variables is more than number of equations.
2. .introducing matrix functions: like det(determinant), inverse or sudo-inverse,...
3. logic operations and their related functions: like and,or,xor,not and also you will learn how to create matrieces which are results of comparing other matrices.

Also in this session I tried to obey Parisa's suggestion. She suggested finding a way for exporting modified variables to audio files. She believes that there should be something like this in MATLAB, but till now I haven't find anything. I found "export" in "signal processing tool" and also "save as" in both "Signal processing tool" and "File menu", but they didn't work.
While I was searching for exporting data I found out "Signal processing tool" which is accessible from "Start" menu. This tool seems really powerful. We can import MATLAB variables into it. Then it will plot the variable and also its spectrum. I think another useful option is the ability to play a sound related to the variable.
As I said in previous session (my previous post), I modified the original data and converted it to a vector of 0-800. Now I imported original data and also modified one into the "signal processing tool" and compared them. I noticed that there's no critical difference between them. The only difference is that modified data has more energy that the original one. In fact you'll hear it with a higher volume.
So at this moment I'm thinking about 2 main ideas:
1. Finding a way (ex. a C program) which can separate bytes of an audio file and easily modify and then save it.
2. modify data in matlab and change every number of data's vector base on esoteric data and then bring it back to its own energy.(by minusing(?) 412 and dividing by 1000) and then compare it with original data by the means of "Signal processing tool" in MATLAB.
this picture shows this powerful tool:


To do list for next session:
1. thinking about 2 statements above
2. continue studying MATLAB-jahad from section5