It happened about three weeks ago, 7 Nov 2009. Our network officer, Kuya Doods, and I tried to the computer connected to the FMCW radar transmitter and receiver to our local network. In this way, I can access the data from my computer. The FMCW radar computer has two USB ports each connected to two external hard drives for storing the radar data. One is for the Manila Observatory. The other is for the SERC. These hard drives have sufficient memory for one year of data.

We were not able to network the computer. Kuya Doods asked me if we restart the computer. I say let it be. I think everything went awry after that. The data are not anymore immediately sent to Japan. But if I restart Matlab and type “manila_startup” then press “Enter”, the Matlab will “melt” the ionosonde data into visualizable graphs of the frequency versus virtual height. After it melts the data in its stack, it waits to for its stack to get filled again. Then I must restart Matlab again. I emailed Akihiro Ikeda about this problem and he said there is a problem with Matlab file sending. They will come here this 4 Dec 2009 together with Dr. Abe. They will also change the protocol so that no data will be lost when one of the USB ports is removed to allow saving of data in flash disks.

Yesterday, the stack got filled to the brim and computer hung. I panicked. I pressed the restart button of the computer. I thought all the data were lost. But they were not. They were melted properly. And what’s more, it seems that each data set is immediately sent to Japan. The stack height is reduced to one at any time.

I think it would still be good that Akihiro and Dr. Abe will be here. My graduate student, Vernice Casareno, can already read their Matlab code. I shall introduce her to them. There are some parts that she can’t understand because the comments are in Japanese and she has no Japanese character file translator. She reverse engineered the process and she can transform the .lzh files into Matlab figures. The code looks simple to her because she works as software engineer in Cannon. I am glad I have a hand here because I am primarily a theoretician and not a programmer.

Rieccoci qui, immersi negli abissi sconosciuti della matematica!
Oggi vi propongo questo quesito:

Sapendo che j è l’unità immaginaria, quanto fa ?

Non usate trucchi come calcolatrici o programmi tipo matlab! Voglio vedere tutti i passaggi!

Buona Fortuna

Condividi su Facebook

Después de varios días de inactividad bloguera, vuelvo a las andadas:

Parece que Matlab y yo nos hemos reconciliado y, aunque sigo con mi cruzada por el software libre y sigo apostando por Octave, en el trabajo utilizo indistintamente ambos.

Mi gran logro ha llegado hoy, de mano de la inspiración divina y la ciencia infusa, aunque tengo que dar las gracias a un sueño que tuve anoche, os pongo en antecedentes:

Llevo una semana y media enfrascado en la difícil situación de cómo conseguir que Matlab/Octave, más concretamente el paquete Psychtoolbox, entienda que cuando quiero utilizar 3 imágenes e interactuar con ellas para “montarlas” una sobre otra no significa que quiero sustituya una por la otra, sino que las 3 funcionen a la vez. La finalidad de ésto es mostrar a los alumnos de la Escuela de Óptica de la UMU cómo es realmente la visión humana (prometo colgar un par de imágenes).

Pues bien, anoche tuve un sueño en el que las imágenes iban cogidas de la mano y la primera de ellas guiaba a las otras y una lucecita se encendió en mi cabeza, a pesar de mi cansancio de anoche (llegué más tarde de la cuenta gracias a los dos engendros que tengo por compañeros de tertulias y puesta común de ideas y proyectos)… como iba contando, a pesar del cansancio, enchufé el ordenador, arranqué Ubuntu (sí, trabajo en casa con soft libre) y Octave hizo el resto, escribí unas cuantas líneas de código, guardé y ejecuté la simulación…

Parece que las imágenes no eran tan amigas como en mi sueño, me vuelvo a la cama a chafar un poco la oreja…

Aquí estoy yo programando con Octave

¡Otro sueño! Las imágenes ya no van de la mano, simplemente la primera guía al resto con una linterna en la mano en medio de la oscuridad, simplemente que una le dice a la otra por dónde debe ir y ésta a la última… Vuelvo a conectar el ordenador, arranco Ubuntu, Octave… escribo líneas de código, parece que va… pantalla en blanco… pantalla en gris… me crea las máscaras de transparencia… monta solo dos imágenes… ¡no! hace un pequeño esfuerzo… ¡sí! monta las tres imágenes… faltan depurar un par de detalles, pero el resultado es esperanzador.

Por cierto, no puedo olvidar que las imágenes fueron desenfocadas por mi coleguita Antonio de BBAA (también fue cámara de televisión, pero prefiere que no le recordemos esa época… una larga historia).

PD. El viernes 11 de Diciembre conferencia en el Centro Social Universitario de la Universidad de Murcia (con la flecha verde) sobre mi labor como Becario de Investigación, trataré de llevar simulaciones y unos cuantos ejemplos.

Ok, this mainly applies to Engineering and Science students… Probably to many graduates who are in the same field as well.

In your time in university, there will be many occasions where you require specialised software for the module you are taking. Most of these softwares recommended by the lecturers are commonly:

- Many version outdated (to the point its free)

- Student versions (SV) which is usually many versions outdated

- Old and outdated to the point that it’s incompatible with Vista and Win7

- Trial software with a license that would last about 3 months (about the length of 1 semester)

- Highly inadequate functionality as it’s free

Now why the hell would they recommend such crap software? Simple, we all like to work on our own computers  and not camp on campus fighting for computer terminals… Hence, lecturers like to help us a little by recommending some software that is free and supposedly adequate for the module. However, as you progress beyond the learning stage, you end up researching and realise that the shit that you’ve got in the computer is like 1% of what you really need… Here’s an example.

Dev C++ is a C++ programming tool. It’s free, it’s highly outdated (as it’s used to test for some higher version which i cannot remember), it works, but here’s the catch. While compiling and verifying, it tells you that there’s an ERROR, not a syntax/int/float/whatever? error, but an ERROR. That’s all it’ll tell you. You either know what’s wrong or go figure. On the brighter side, you get damn good at spotting your own errors and know exactly what needs to be done, eventually (usually by the time the module is over).

So let me get to the point of this… There are some work-arounds available to such crap software and I’d like to share them with you. At the same time, I’d like to recommend some software that is worth some “investment”.

Eclipse

OS: Mac OSX and Windows

Price: Free

Eclipse provides and extremely powerful environment for the programmer, noob or pro, to program and debug the program.

Circuit Maker SV

OS: WinXP

Price: Free

Circuit maker is an extremely old circuit simulation software that not only allows for schematic drawing, but also comes with PCB layout functionality. Circui Maker has recent been renamed into Altium which is somewhat the same, but no free version to my knowledge.

MATLAB

OS: Win XP, Vista, Mac OS X

Price: Unknown (but it’s about 200-700 depending on SV or Retail)

MATLAB 2009 comes in several version, 2009a, b and c. 2009b is what I consider the retail product offered to general users whereas 2009a is the student version. 2009r would be the enterprise version with multiple licenses. Though expensive, you would be using this software for a good portion of your study. All versions come with Simulink, a powerful simulation software that allows you model and simulate just about anything.

IMAP supported e-mail application Exchange would be good as well)

There is no right answer for this, there are some commonly available applications:

Outlook – Windows

Mail – Mac OS X

Mozilla Thunderbird – Linux, Windows, Mac (Free)

In your lifetime, you’d accumulate several e-mail addresses for some strange reason. Like me, you probably started with something like extraboy1985@hotmail.com, then as you got older, you thought to yourself “what the f*ck was I thining?!” Opened a new account like j_boy@hotmail.com, again, WTF?! Still, you stuck with it. Then realised that hotmail sucks and moved to Yahoo or whatever. You realised that you’d like to keep some of these e-mail accounts (for some strange reason). Admit it, you bitch and complain about logging on to ALL YOUR 3-4 accounts everyday and having to clear them one-by-one. Not only that, you now have school/company e-mail to handle…

E-mail applications to the rescue! Most applications come with 2 basic incoming e-mail protocols, POP3 and IMAP. POP3 is extremely simple, it just scans your mail account and downloads all the new mail (depending on how much you want to download, can be just the subject or the whole damn thing). IMAP however, synchronises with the account, and basically sets up all the folders you have in the account as well (this may get irritating, but there work-arounds). So, what ever you see in your app, is what’s in the online account. This gets really handy for handling multiple e-mail accounts and most of these applications update you with some form of alert. Hence you do not need to remind yourself to check your mail.

Of course, you can always use mail forwarding and stuff, but why bother to start up your browser and again check you mail when you have an app that’s already up and running and constantly checking your mail? There is one thing to note, hotmail does not support any of these applications, hence, I suggest you switch to something else, like Gmail which comes with IMAP.

With regards to further management of E-mail accounts, I’ll leave it to YK as he’s got something on hand.

It is starting to get cold.

After trying to program an almost intractable problem it is fun to help my roommates with their Matlab homework. Especially since I have never had a dedicated programming course before. And because their homework problem is very reasonable in what it asks and what it needs.

VLF attenuation in the earth-ionospehre waveguide is not as easy.

Í gær var ótrúlega fallegt veður svo ég tók mér pásu frá Matlab forritun og skokkaði einn stuttan hring í hádeginu. Þetta er liður í átakinu Í kjólin fyrir jólin sem hófst á mánudaginn með eins kílómetra sundsprett í hádeginu.

gúúgel jörð hjálpaði mér við þetta

Hringurinn sem sjá má á mynd 1 var hlaupinn á 25:08 min sem gerir ca. 12 km/klst. Kannski ég hendi upp Matlab forriti til að fylgjast með hlaupunum. Djók.

Fór svo til tannlæknis í hádeginu í dag. Tannréttingartannlæknis. Ég hafði ekki farið til hans síðan 2004 og ætti held enn að vera nota helvítis góminn sem ég hef örugglega ekki notað síðan 2004. Þetta leit þó allt ágætlega út sagði hann nema hvað ein tönn hafði færst örlítið. Hann vill því taka járnspelkurnar í efrigóm (já, ég er með svoleiðis) en búa til nýjan góm sem ég get notað bara svona til að tjekka hvort allt sé ekki á sínum stað. Spelkurnar í neðri góm (já, ég er líka með svoleiðis) fæ ég hins vegar að taka með mér í gröfina að hans sögn. Jei. Þessi maður er smámunasamasti tannlæknir á Íslandi er ég viss um og mig minnir að Sverrir hafi tekið undir það með mér, tannlæknaneminn sjálfur.

After trying to get a lot of my friends(Rushi, Avdhut, Abhinav, Pooja, Hari and Deepti) to read “Template matching using the parametric template vector with translation, rotation and scale invariance” by Yi-Hsien Lina, Chin-Hsing Chenb I was still unable to completely understand the algorithm. After some final discussion with Deepti and Avdhut, I think – even with an incomplete understanding – I am in a position to begin.

The first thing that has to be implemented is the algorithm to find the ring projection vector. The circle drawing algorithm published a few posts ago comes in handy – only instead of writing the circle pixels, the intensity values have to be read from the pixels. The following matlab code converts a given template to a 1-D vector which is the templates ring projection transform. That is, it consists of average intensity values on concentric circles starting from the center of the template. The last circle is the largest circle that can fit within the template.

—————————————————————————-

%Title: Ring Transform for Template Matching
%Author: Shashank G. Sawant
%File Name: ringtrans.m
%Notes: Converts a given template (or any part of a sufficiently
%large image) into a 1-D Vector. It calculates the average pixel
%intensities at progressively increasing radii and stores them in a vector.
%Parameters:
%img – The image or template whose ring transform is required
%y – The y coordinate of the center of all the circles
%x – The x coordinate of the center of all the circles
%lr – the radius of the largest circle.

function ringvect=ringtrans(img,y,x,lr)
ringvect=1:lr+1;
for i=1:size(ringvect,2)
ringvect(i)=readcirc(img,y,x,i-1);
end

% Title: Read Circle Values
% Notes: Accepts an image, the circle’s center’s coordinates and radius as
% the arguments. Calculates the average value of pixel intensities on the
% circle thus specified.

function avgint =readcirc(imgmat, yCenter, xCenter, radius)      %
x = 0;
y = radius;
p = floor((5 – radius*4)/4);
global cir_val cir_pix_num;
uint32 cir_val;
uint16 cir_pix_num;
cir_val=0;
cir_pix_num=0;
cirpoints(imgmat, yCenter, xCenter, y, x);

while x < y,
x=x+1;
if (p<0)
p = p + 2*x+1;
else
y=y-1;
p = p + 2*(x-y)+1;
end
cirpoints(imgmat, yCenter, xCenter, y, x);
end
avgint=cir_val/uint32(cir_pix_num);
return;

function cirpoints(img, cy, cx, y, x)
if (x == 0)
readpix(img, cy + y, cx);
readpix(img, cy – y, cx);
readpix(img, cy, cx + y);
readpix(img, cy, cx – y);
elseif (x == y)
readpix(img, cy + y, cx + x);
readpix(img, cy + y, cx – x);
readpix(img, cy – y, cx + x);
readpix(img, cy – y, cx – x);
elseif (x < y)
readpix(img, cy + y, cx + x);
readpix(img, cy + y, cx – x);
readpix(img, cy – y, cx + x);
readpix(img, cy – y, cx – x);
readpix(img, cy + x, cx + y);
readpix(img, cy + x, cx – y);
readpix(img, cy – x, cx + y);
readpix(img, cy – x, cx – y);
end
return;

function readpix(img,y,x)
global cir_val cir_pix_num;
uint32 cir_val;
uint16 cir_pix_num;
cir_val = cir_val + uint32(img(y,x));
cir_pix_num=cir_pix_num+1;

return;

—————————————————————————-

Following is the image of a ship’s profile (it’s incomplete but the features are sharp).

The size of the template is small (39 x 39).

img=imread(’ss_ship.jpg’);
img=rgb2gray(img);
ringvect=ringtrans(img,20,20,19);
plot(ringvect,’*');

The above commands yield the ring projection vector, which when plotted, looks like:

The values near the origin represent the darkest (red color) parts of the ships. As the circles enlarge, more and more white part (surrounding the ship) get included and the value of the rpt vector increases along the +ve X-axis.

To visualize the 3D matrix just consider that them as stack of images or layers.

{There is one more very important way,  that is third dimension representing the feature vector’s length}

So a(:, :, i) = all elements in the layer i, so changing i will give you next image.

where a(r,c, i) will move in the image.

a = [];
a(:,1,:) = [111 112 113 114 ; 121 122 123 124 ; 131 132 133 134];
a(:,2,:) = [211 212 213 214 ; 221 222 223 224 ; 231 232 233 234];
a(:,3,:) = [311 312 113 114 ; 321 322 323 324 ; 331 332 333 334];
a(:,4,:) = [411 412 113 114 ; 421 422 423 424 ; 431 432 433 434];
a(:,5,:)= [511 512 513 514 ; 521 522 523 524 ; 531 532 533 534];

Will make the 3D matrix ‘a’

size(a)

ans =

     3     5     4

That is there are 4 images and each image is of 3 rows and 5 cols.

But let’s Say you want to represent 3rd dimension as the feature vector  so each a(r,c, : ) represents a feature vector.

Now let’s say you want to make a 3D matrix from one feature vector.

vt = squeeze([a( 2,1, : ) ] );
vt = vt(:)';
%//make it into 2 by 3 by length(feature) matrix
%//repmat will repeat this matrix and make a 6 row matrix
%//the reshape picks the elements from the 1st col, 1st row and start moving downward in the row and so on
%//therefore each time it will meet same element as it moves down the row and fills our first image
tempT = (reshape(repmat(vt, 2*3,1), 2, 3, length(vt)));
size(tempT)
ans =
     2     3     4

source: http://desk.stinkpot.org:8080/tricks/index.php/2006/02/how-to-get-matlab-to-talk-to-mysql/

the codes: (store to mysql db from matlab) -> link
%buat koneksi dengan database mysql.
conn = database('tws','root','password','com.mysql.jdbc.Driver','jdbc:mysql://localhost:3306/tws');

%preparing the result from fem and converting the data to cell type.
dd=d';
dd=num2cell(dd);
for i=1:25
exdata(:,i)=dd(:,i);
end

%what columns would be insert to.
colnames = {'tf1','tf2','tf3','tf4','tf5','tf6','tf7','tf8','tf9','tf10',...
'tf11','tf12','tf13','tf14','tf15','tf16','tf17','tf18','tf19','tf20',...
'tf21','tf22','tf23','tf24','tf25'};

%insert some pieces of data.
fastinsert(conn, 'fem', colnames, exdata);

-Alhamdulillah-
agung.ridwan.sn

Brand : Coke

Agency: McCann

Baseline : Piyo sar Utha Ke

Well ……..

Marketers some times behaves like fools !!!!!!

Why the hell one should change their best positioning statement ? Every one loved the ” thanda ” campaign, there were rave reviews about Aamir and Coke. People looked forward to the next Aamir avatar ………

coca cola

Then it was a surprise.. there is no thanda but some blabbering about drinking coke ” Sar Utha ke?

Coke never had good time with respect to its advertising in India. Never in their second life in India, they have delivered good campaigns. Pepsi always scored with their campaigns like” Ye dil maange more” Yehi hai right choice baby”, ” Nothing official about it”.

Then came the Thanda matlab “Coca- Cola” campaign which blew the hell out of Pepsi. Well how can anyone own some thing like ” Thanda”. Similar to XEROX, Coke was trying to own a whole category as such.

Then Coke changed the campaign , Why? I don’t have the answer may be the creatives in McCann may have it. The current campaign speaks nothing. I use a straw to drink Coke, so how can I drink coke sar Utha ke? Most of the time when I tried drinking directly from the bottle, I had encountered some unpleasant taste of “rust” from the cap of the bottle. What about the South Indians and othe non Hindi speaking consumers? Will they be impressed by the base line?

An opportunity lost for Coke . they had one BIG IDEA in ” Thanda Matlab Coca-Cola “and they blew it off

marketingpractice.blogspot.com/2005/11/coca-cola-thanda-nahin-hai.html

“Experiments are as good as your instruments and simulations are as good as your assumptions” – Prof. D. K. Ferry, Arizona State University

This post will discuss the basics of simulation (done by writing a code in any of the many programming languages). There are numerous tutorials on the web and there is no dearth of good books on this subject hence I will keep it very simple. The following figure will help in the discussion.

Imagine you have a rectangular surface of length ‘L’ (along x-axis) and width ‘W’ (y-axis) and you need to model some physical process in that region. The idea is to divide the region of interest into many points (grid) and solve equations describing the physical process at each grid point and this would tell us how the physical process would behave within the rectangle.Now one of the first things to do is to decide on a suitable grid size, i.e. the distance between two grid points (indicated by ‘a’ in the above diagram). The grid size should be small enough to capture the intricacies of the process, i.e. smaller than the characteristic distances within which interesting phenomenon occur but it should not be too small (more on it in the next paragraph). In this case a grid size of ‘a’ divides the width into ‘k’ points (k-1=W/a) and length into ‘m’ points (m-1=L/a). Thus any point in the rectangle can be represented by a 2 element co-ordinate system. For example the red dot is (3,4), i.e. 3rd row and 4th column. Sometimes it would be convenient/efficient to use a radial co-ordinate system (r,θ).

Now comes the computation: the above paragraph indicates that in total we have ‘m × k’ points and the equations describing the physical process must be solved at each of these points. This leads to the lower limit of the grid size. If it is too small then the number of points where one must perform computation increases hyperbolically; very soon your code’s run time will get increasingly uncomfortable and your program/computer may run out of memory. The initial tests of your simulation should be aimed at determining an optimum grid size. Note: In some cases the grid size may have one value for the horizontal axis and a different value for the vertical axis, in this case the grid size will be ‘a× b’ where ‘a’ is the grid size along length and ‘b’ is the grid size along width. And there are cases where the grid size may be variable, i.e. small in areas of interest and large in nonessential areas.

As some of you may have noticed this is a 2 dimensional (2D) simulation since there are two length based attributes in our region of interest, namely the length and the width. This can be expanded to perform a 3 dimensional (3D) simulation by solving the equations along the z-axis also but be prepared to compute in at least ‘m × k × p’ points! and not to mention the visualization problems while handling a quantity in 3D space. Note: In 3D, there are at least 4 entities to handle out of which three are the distances (dimensions). Also note that this type of grid is also known as mesh or lattice system and this type of simulation is also known as discretization.

In my case I am interested in solving the Schrodinger equation in a 2D system whose size is typically in the order of few 100 nm by few tens of nm with a grid size of about 1 nm (nm = nanometer). This will allow me to see quantum effects that happen in the scale of few nm.

In the end one has to remember that in any simulation you get what you put in. If you ever feel you are seeing new phenomenon then all it means is that either you did not completely understand your system dynamics/equations or there is an error in the code or data. In most cases it will be the latter

To install those software packages it is necessary to install first the library ‘libstdc++5′ manually. Since it is not available from Synaptic it is necessary to download it manually.

Additionally, for Matlab, after installing it we have to do

root# cd /usr/loocal/matlab

root# ./install_matlab -glnx

and say yes to all the questions. Then, do (still in /usr/loocal/matlab ):

root# cd bin

root# gedit matlab

and add the following line AFTER the FIRST ONE (#!/bin/sh):

export AWT_TOOLKIT=3DMToolkit

and save the file and exit. Now, you should be able to load Matlab without problems and from anywhere.

Afrakstur dagsins enn sem komið er. Matlab kóði sem tekur inn niðurstöður úr SAP2000 sem hafa verið exportaðar í Excel skrá. Matlab skráin tekur svo við þessum gögnum og flokkar þau á hentugan hátt svo hægt sé að dunda sér með þau. Það er gaman í Matlab þegar vel gengur. En ömurlegt þegar illa gengur.

Oh it turns out that the matlab does not copy the data while passing it to the function if the function is not changing the values.
Which is big saving.
http://blogs.mathworks.com/loren/2006/05/10/memory-management-for-functions-and-variables/#1

In the previous article we reviewed the process for publishing a matlab application as a web service

http://iomes.wordpress.com/2009/11/09/publishing-a-matlab-application-as-a-web-service-the-caiman-php-service/

In this article we describe the configuration and start up of the service which will accept client requests for running matlab tasks.

In this case the example service for the CAIMAN project is considered. For the CAIMAN project results are emailed to the user but the web client it self may request results files from the job server, this aspect is considered in another example.

Files for setting up the IOME job service for the CAIMAN matlab service are contained in the folder src/examples/matlab/caiman-ws. The folder caimanDir contains the main function files used by the matlab routines. Once the caiman-ws folder has been copied into a suitable working area, the CAIMAN job service can be started almost immediately with relatively minor modification. We describe some of the required modifications here. The main files for enabling the CAIMAN service are as follows

• iogenericsim.sh  , this routine is called when a submit (or request ) simulation is received from a client a unique job working directory is created an this script is copied into that directory. The example provided here submits a further script to a job scheduler (sun grid engine). It could easily be modified to submit to a generic process scheduler available on windows/linx (this line has been commented out.
• iogenericsim_sge.sh the actual script that runs invokes the matlab application will be described below
• simfile.xml an example of the simulation input file this is received from web client and is located in the job working directory
• caimansaasexample.m, the matlab script that styarts the actual processing job
• cpanellogin.sh

The main modifications to be made are

• qsub -sync y iogenericsim_sge.shFor the file iogenericsim.sh, If you are using sungrid engine or PBS as a batch scheduler then remove the comment from the line reading #    ’qsub -sync y iogenericsim_sge.sh . Place a comment at the start of the  line   ../iogenericsim_sge.shFor iogenericsim_sge.sh, check and modify (if necessary) the line    ftp -i staff.shef.ac.uk < cpanellogin.sh , this should refer to the corrrect ftp serverThe cpanellogin.sh file should be modified at the first line as follows, cd public_html/iometest/uploads, the directory should refer to the uploads directry for the IOME client
• Using batchmode to access the ftp server store ftp server information in a file in $HOME called .netrc the .netrc filehas the following line (or lines) “machine iomewebclient.organisation.ac.uk login username passwd thepassword”. It is important to set the permissions for .netrc to  600(rw—-). Further details may be obtained at ( http://rcsg-gsir.imsb-dsgi.nrc-cnrc.gc.ca/documents/internet/node52.html )

The IOME service is then started with the following invocation

iogs initiome null caiman null 60000 >& iogs.log

Putting this command in script file e.g. called startserver.sh

#!/bin/bash

iogs initiome null caiman null 60000 >& iogs.log

The server is started using the command

./startserver.sh &

At this point the IOME example CAIMAN service will be operational. We now provide some additional comments enabling the developer to undesrstand how to deploy their application as a web service.

The IOME web service works in the following way.

• Receives a submitsimulation request and creates a working area
• Receives a copy of the simfile.xml that contains the job description
• Executes the iogenericsim.sh script

The iogenericsim.sh script is provided by the author of the service and this will invoke the following.

• Starts a local server
• Reads the simfile.xml into the local server
• Starts the actual job on the server the actual job will then read any data from the server (alternatively we could use string replacements to edit an input file. There is a large number of possibilities here. It is also possible to parse the simfile.xml file directly with out invoking a local IOME server

Reviewing the iogenericsim_sge.sh script it should be noted that the actual job starts its own IOME server which runs as a localhost server and is invoked using the command “iogs initiome null $IOME_SIMNAME null  &”.  Data is loaded onto the server using the command “iogs readsimulation simfile.xml 0 $IOME_WSPORT localhost”. We then obtain the name of the imagefile to be processed using command ” IMFILE=`iogs getparam string imagefile 0 $IOME_WSPORT localhost` “, this is used in the stream editor command for editing the ftp input file. The final line of iogenericsim_sge.sh invokes the matlab job.

The main features of the matlab driver script are as follows

• Reads the port for the local IOME server
• Sets up contact details for the local IOME server ( e.g. “elist=iome(‘localhost’,res{1},0);”  )
• Requests the parameters for the job from the local IOME server e.g. “userEmail=getparamstring(‘useremail’,elist);”, “ imageFile=getparamstring(‘imagefile’,elist);” and “jobtype=getparamstring(‘jobtype’,elist);”
• At the end of the routine terminate the local IOME server using “exitiome(elist);”

An earlier entry on generating web service applications

http://iomes.wordpress.com/2009/09/25/publishing-an-application-as-an-iome-web-service/

Just in mid of the code wanted to find the Running Variance, just as habit typed and found not so good links.

1/N*[sum(i=1:N-1, Xi*Xi') + X*X'] – (1/N^2)*[ sum(i=1:(N-1), Xi) + X][ sum(i=1:(N-1), Xi) + X]‘

Matlab code for calculating the running Variance is as follow

%updating Mean

newMean = (newMean*(N-1) + X)/N;

sumOfSq = sumOfSq*(N-1)  + X*X';

covMat =  (1/N)*sumOfSQ - newMean*newMean'

Externally there are few links that are worth reading

• Accurately computing running variance
• From Google Answers, someone gave even the posted Java Code ; Simple and clear that could be easily read by any one knowing any programming language

In the previous blog, we spelled out the bubble sort algorithm for putting an array of numbers in an ascending order.   In this post, I am posting the matlab program. It is better to download the program as single quotes in the pasted version do not translate properly when pasted into a mfile editor of MATLAB or see the html version for clarity and sample output.

%% PUTTING AN VECTOR OF NUMBERS IN AN ASCENDING ORDER?
% Language : Matlab 2007a
% Authors : Autar Kaw
% Last Revised : November 8, 2009
% Abstract: This program shows you how to put a vector
% of numbers in an ascending order using the bubble sort method
clc
clear all
disp(‘This program shows the bubble sort method’)
disp(‘to put a vector of numbers in an ‘)
disp(‘ascending order’)
disp(‘Matlab 2007a’)
disp(‘Authors : Autar Kaw’)
disp(‘Last Revised : November 8, 2009′)
disp(‘http://numericalmethods.eng.usf.edu’)
disp(‘  ‘)
%% INPUTS
% The vector of numbers
disp (‘INPUTS’)
disp(‘Input the vector of numbers’)
A=[18  7  6  15  4  13];
disp(A)
%% SOLUTION
% Number of entries, n
n=length(A);
% making (n-1) passes
for j=1:1:n-1
    % comparing each number with the next and swapping
    for i=1:1:n-1
    if A(i)>A(i+1);
        % temp is a variable where the numbers are kept
        % temporarily for the switch
        temp=A(i);
        A(i)=A(i+1);
        A(i+1)=temp;
    end
    end
end

%% OUTPUT
disp(‘  ‘)
disp (‘OUTPUT’)
disp (‘The ascending matrix is’)
disp(A)

_______________________________________________________

This post is brought to you by Holistic Numerical Methods: Numerical Methods for the STEM undergraduate at http://numericalmethods.eng.usf.edu, the textbook on Numerical Methods with Applications available from the lulu storefront, and the YouTube video lectures available at http://numericalmethods.eng.usf.edu/videos and http://www.youtube.com/numericalmethodsguy

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This post deals with a Matlab simulation showing the formation of a quantum wire, i.e. a parabolic potential well.

Such potential profiles can be easily realized by negatively biasing 2 metallic plates (also known as gates) separated by a short distance as shown in the figure below. Split-gate technique is one method used to form (fabricate) such structures.

2 plates (on top) with negative charge

In the following movie, the potential starts with a flat profile (at zero/ground potential) when there is no charge on the plates. As the negative potential is increased the potential under the plates rises and the fringing field (field that is not directly under the plates) pulls the neighboring potential along with it – almost like lifting the ends of a bed sheet. The title calls it the ‘Parabolic potential well’ since the transverse cross section (section along the width) shows a parabolic shape for the potential along the width of the wire.

The Length and Width axis of the wire are in units of nano-meter (1 nm = 1*10^-9 m, i.e. 1 billionth of a meter). Nanometer is the typical unit for length used for measuring dimensions in the nano world. The Potential axis is in arbitrary units of electric potential. All the numeric values are chosen to represent typical values seen in actual experiments.

Once the wire is formed in the simulation, it is rotated (in the above video) to give a clear view of its shape (remember the edges are electric potential and not physical walls/matter). The last segment of the video shows the top view of the wire which will be a useful view to get used to when we will pass electrons through the wire. The color bar on the right hand side gives the value of the potential at any point in the wire based on the color gradient; maximum is 25 (red) and minimum is 0 (blue).

Feel free to post any questions…………… thanks