Wednesday, April 19, 2017

ScreenCasting 2.0

ScreenCasting 2.0 
Recently, there was a discussion on how best to make ScreenCasts for our students on the AP Calculus forum. I'm no expert, but I've been playing with tech in the classroom forever, so here's my 2 cents anyway:

I've been ScreenCasting and "SmartBoarding" for my students for 10 years now, way before Kahn Academy was a household name and long before we had actual SmartBoards at my school! So, I guess I'll say I'm self taught and have learned a thing or two from my mistakes along the way. 

I've used several different solutions, aka hardware and software combinations, over the years and everyone has their own style and preference. So, please feel free to take from this blogpost what you think you can use and leave behind rest. It's your call!

BTW, above you will see one of my first CompSci ScreenCasts ever from 2009! Also, for comparison's sake, here's a blogpost from 2011 entitled ScreenCasting 101. Here's another related blogpost also from 2011 about SmartBoards and Linux!

Please note: I have used Linux, not Windows or Mac, since it came out in 1995. However, I'll try to describe OS neutral solutions. 

I started with a BlueTooth tablet and a PC projector both attached to my desktop PC. If I recall correctly, the tablet was a Wacom Graphire 6x8 (10" diagonal) which was nice since it connected easily over BlueTooth using a BlueTooth dongle in a USB port. 

Actually, we got this tablet from a SmartTech rep rebranded as the Smart Airliner Slate. That's how I got a copy of SmartNotebook before anyone else at school! This tablet also had a capacitive surface and the stylus had a magnetic tip which made it easy to hover over the tablet as a pointer without writing. 

The problem with this tablet was that you had to crane your neck to see what was displayed on the PC Projection Screen. Unlike a modern Android Tablet or iPad, you could not see anything on the tablet itself! I also had a cheap lapel Mic (FM 75MHz) from Radio Shack! In addition, I had a nice PC Projector from Donorschoose

Finally, I made my recordings "Live" during class so they were about 40 minutes each at my High School and 1 or 2 hours each at my Community College Summer Session. See above my first AP Calculus BC ScreenCast ever at the High School from 2009!

Now I'm trying to make what I call "Shorts" whereby I record only 10-20 minutes after the lesson in question has been taught in class summarizing just the most important points (see preCalculus sample above from 2017). As far as my hardware and software solutions go, I have primarily settled on 2 different styles, one for Math and another for CompSci.

When I'm recording a Math lesson I like the freedom I have to draw all over the SmartBoard (see sample preCalculus Midterm Review above from 2017). So I attached a nice USB Mic by Blue Yeti right next to the SmartBoard up in the front of my class. 

Everything I write and say is recorded from the SmartBoard. I know some people use SmartNotebook Recorder but that program makes really huge video files. So, I use SimpleScreenRecorder for Linux. A similar program you can use in Windows, running right off your Chrome browser, is ScreenCast-o-matic (I was a beta tester when they had Linux support) which I use whenever I'm on the road (conferences, summer school, etc). I then upload an MP4 file directly to my YouTube channel and link the video to Edmodo or Blogspot for sharing with my students. 

When I record for Computer Science class, I am not usually at the SmartBoard writing equations and drawing diagrams all over the place like a mad scientist (my kids think I'm like Sheldon, as in the mad scientist in TBBT: The Big Bang Theory sitcom on CBS). More often than not, I'm typing code and explaining what I'm doing as I'm typing away (see sample CompSci lesson above from 2014). To accomplish this I add a keyboard and mouse to my SmartBoard, on the PC in the back of the room, and record as above. My room is setup (see masthead) with the Teacher PC that's connected to the SmartBoard in the rear of the room so that I can see everyone is on task as I'm teaching CompSci since all the Student PC monitors face the rear.

However, lately I've ditched the SmartBoard, PC, Projector, Keyboard and Mouse entirely. Please see the Math (2016 post AP Exam review) and CompSci (recent 2017 classwork) samples above.

BTW, I don't like SmartNotebook much either. Any Pen App that saves your work to pdf to share with students will do. I like to use Xournal, for example. I don't need all the bells and whistles in SmartNotebook. I've said this many times before, but here we go again: Don't drink the Kool Aid!

Anyway, lately I've found that working with a more modern tablet (ie: not the Wacom) to be a much better solution. A modern tabIet, weather it be Andriod or iOS based, has a lot more horsepower under the hood and a high resolution, high contrast color display showing everything you write as you write it. Imagine the luxury! 

I would strongly recommend a high-end tablet if you go this route. I hear a 3-in-1 (with tablet, laptop and tepee modes) like the Lenovo Yoga is very nice. However, the Yoga is a Windows based device. Sorry, I'm not a fan. I like to use FOSS: Free Open Source Software. Technically, I prefer to use FLOSS everyday (Free Linux Open Source Software). BTW, I won't touch iOS either (too proprietary). 

I'm using the Samsung Galaxy NotePro 12.2" Android Tablet (Android is based on Linux). What's nice about this solution is that the S-Pen is very easy to use if you want to do Math Lessons and everything you need to ScreenCast is built into this one device. You don't even need a SmartBoard, projector or mic! The tablet stands in for all those devices in one! However, if you want to type, as in a coding class, you may want to add a BlueTooth Keyboard and a BlueTooth Mouse (the virtual keyboard is hard to use and covers half the screen when in use). 

A high quality mic is built in and there's tons of free apps in the Google PlayStore you can use for writing or typing and saving your notes or code as well as ScreenCasting apps. Right now, for example, I'm using the Autodesk Sketcher app for writing notes that I save to my Dropbox app and link to my Edmodo app. 

Lately, I've been using in the Chrome app to type code. I've found the AZ Screen Recorder app very easy to use and I post my ScreenCasts directly to my YouTube channel via the Youtube app. 

I also have emulator apps for the TI-84C (Wabbitemu) as well as the TI-89 (Andie's Graph), TI-92 and even the TI-59 (for us old timers)! If I want the TI-nSpire, I have to use my SmartBoard as I have an emulator that is a Windows program called KARMTI running under WINE on my Ubuntu Linux 64bit Desktop.

Sometimes I find myself in a situation where I don't have access to a SmartBoard. So, I use my tablet as a "Portable SmartBoard!" With a mirroring app such as TeamViewer or SplashTop (free to use only if all devices are on the same WiFi router) you can mirror your desktop to your tablet while your desktop is displayed on a PC Projector. Then you can control the whole shebang from your tablet using the S-Pen or BlueTooth Keyboard and Mouse!

Some classrooms at my school were recently "upgraded" to Epson BrightLink Interactive WhiteBoards which are larger and brighter than our SmartBoards (even bigger and brighter than my extra wide 78" SmartBoard with 885xi projector). 

The Epson whiteboards compete with SmartTech by addressing SmartBoard's shortcomings. For example, you can write on the board and share your notes without even connecting a PC. You don't need any software but there is a software package with extra features that's free! Everything you need is built right into the projector's hardware! Also, the projector can cast an image on any surface, even a table top for group work, so you don't need any special hardware in the board itself, any marker board will do. 

I think I'm going to have to stop referring to all this as ScreenCasting or SmartBoarding, how about Interactive WhiteBoarding?

IDK if I want this "upgrade." I do like the bigger and brighter image. Unfortunately, there's two problems with this hardware solution:

1) Epson's hardware and software are not compatible with SmartNotebook. So, if you drank the SmartTech rep's Kool Aid and wrote tons of notes over the years with SmartNotebook using all it's proprietary bells and whistles.... I'm afraid that you're up a creek without a paddle all on your own, sorry!

2) Also, one writes with an ink layer over a ppt or pdf or just a blank screen and nothing you write on the board shows up on the PC even if it is installed! So, how do you ScreenCast anything? 

Stay tuned for ScreenCasting 3.0 next year, I'll figure it out!

Generally Speaking,

Thursday, April 13, 2017

PAEMST 2017: 3rd Time's the Charm?

PAEMST 2017: 3rd Time's the Charm?
Once more onto the breach, my friends? Well, I hope that the 3rd time is the charm! I think this will be my last attempt at this application process! Hoping for NYS Finalist this time, at least.

I was nominated to compete for the PAEMST award for the first time around 11/1/2012. I went through the whole application process, all 10 grueling steps of it and uploaded my entry by 5/1/2013. But I was not chosen. 

I was nominated again around 11/1/2014 and finished a whole new application by 5/1/2015. But I was not chosen, not even for NYS Finalist? 

I was nominated again around 11/1/2016. This time I was told I could simply resubmit my 2015 application. So, silly me, I waited until now to resubmit, only to find out that I had to reedit everything! I was able to cut and past my essay and resubmit my video (see above). However, I need new recommendations by 5/1/2017! 

If you are not familiar with PAEMST, please see this blogpost from 8/18/2012. Here's my blogpost about my 2013 application. Here's my blogpost about my 2015 application. BTW, my 2013 video is at the bottom of this post.

As you can see above, I'm resubmitting my 2015 class video. I won't bore you here with all 10 steps in the application. The boring parts involve verification of eligibility, proof of employment, school demographics, demographics for the class that was recorded, parental video consent forms, just to name a few requirements. 

The most important parts, after the video, are copied below for your viewing pleasure:
Essay aka Narrative summarizing the video, 
Supplemantary Documents for the Essay, 
Teacher Resume and 3 Recommendations. 

Everything has been updated except for the recommendations. So, I include here the 2015 recommendations.

Generally Speaking,

Thursday, March 30, 2017

AP Calculus BC 2016-2017: March

AP Calculus BC 2016-2017:

UNIT 11 
In our penultimte unit, we use what we learned about series of constants to find where power series converge. The difference here is that a sequence of constants may converge to a number, while a power series may converge to a function!

YouTube Wednesday: Was it Archimedes?

Teaching With Technology,

preCalculus 2016-2017: March

preCalculus 2016-2017:

Chapter 10 was great fun. It was about Conic Sections! We learned about the graphs of Parabolas, Ellipses and Ellipses in General Form and in Standard Form. We played with planet orbits and whisper gardens. We found out about degenerate conics and used polar notation to graph Twisted Conics too!
YouTube Wednesday: Was it Archimedes?

Teaching With Technology,

Wednesday, March 29, 2017

AP Computer Science 2016-2017: March

AP Computer Science 2016-2017:

Believe it or not, we spent most of March on ArrayLists! So last month's posting, repeated below, still applies. However, this month I would like to share a bit of a pep talk that I gave my AP Computer Science students on Edmodo, enjoy!

AP CompSci Pep Talk 2017
The best way to learn how to code is to watch someone else code and try to do some coding yourself everyday! That's what I try to provide for you in class.

Also, the best way to succeed on the AP CompSci Exam is to read and write code everyday even at home! You should be playing around with everyday now that we have a server we can use in class and at home! 

You also need to get the latest Barron's Review book and read and write a little code in there everyday. You should be reading our textbook power points and trying our lab pdfs everyday! 

Just a little advice from your friendly neighborhood CompSci teacher who's been coding for over 40 years!

Ever since Linux came out (1995?), I have always provided my students with a sftp/ssh server they could log into in class and from home. This was a great solution for us as students could work on labs in class, in extra help, in the library and at home. This made our workflow very efficient so that we could do a lot of programming assignments in a short amount of time. I'm used to giving my students a lot of lab time and coding practice everyday!

In recent years, my district has hired out our tech services to some off campus "experts" in IT and Cyber Security. This new "Tech Dept" has found fit, in its infinite wisdom, to change the school's internet firewall in such a way so as not to permit ssh tunnels in or out. My pleas to the contrary falling on deaf ears. So, now my students cannot login from home. I've been struggling with alternate solutions involving Teamviewer, SplashTop and Chrome Remote Desktop just to name a few. These experiments have had varrying degrees of success but still no joy.

This semester I started playing around wih online java IDEs. I tried many and found Cloud9 actually provided an online Ubuntu terminal very much like what we use in class. However, javac is no longer installed and customer service is not very helpful....

cloud9 is free. However, if you want to setup a teacher account, it costs a modest $1 per month.

Why would you pay if it's free? The problem with cloud9 is the registration process. They require a credit card for identification purposes.

Students can join your Team without a credit card if you have a Teacher Account.

Regarding the APCS Labs (Magpie, etc), I still have my local sftp linux server in class for GUI and graphical work.

Most of the work we do all year is more text based, so using or would be fine.

Also, if we want to play with graphics we could use

I'm sticking with for now as my students are doing well with it and it's easy to share code on my SmartBoard as I teach.

c9 is hard to see on the SmartBoard. You can increase font size in the text editor but not in the terminal???

Actually, you can install default-jdk (openjdk) from the commandline much as you do in a standard Ubuntu terminal with apt-get. Here's an example of some coding I did,

If you want to play with c9 you can make one workspace for the whole year, just make a new directory (aka folder) for each project,

Also, make a "custom workspace" by clicking on the Ubuntu icon. They have different workspaces for c++, python, html website dev, etc.

Your Custom Workspace is basically a plain vanilla install of Ubuntu (virtual machine like Harvard's CS50 uses) that works over a web interface.

So, jdk is not installed. Do this once in the terminal (aka commandline):

sudo apt-get update

sudo apt-get install default-jdk

This installs the latest version of openjdk from the debian repositories which is fine for text based work.

However, we did play around with and found it very useful. Students get their own free accounts. Students can store their work with revision histories. Students get a text editor with syntax completion and syntax color highlights (simple java IDE). Students get an ASCII terminal for output. You can use a variety of programming languages too. 

Teachers can get a teacher account where they can set up online classrooms and assignments but I haven't done that. I'm using my account as the students do. Each new project is saved as a separate session. Each session can have multiple files and classes. One thing to watch out for is that the main method has to be in in the Main class. 

Last, but not least, you can share a live instance of any particular revision of any session you want complete with editor, terminal and runner. Here's an example,

Last Month's Post
(NEW: YouTube Wednesday)

Finally, we are ready for Static Arrays and ArrayLists! We started with list traversals using for loops. Our introductory project was Rot13a where we traversed a String as an array of char and ran a Caesar Cypher. Rot13b did the same thing with static int[] arrays. Then we tried Rot13c with dynamic arrays aka ArrayLists!

YouTube Wednesday: Watson on Jeopardy!

Teaching With Technology,

Well, that's all folks,
A. Jorge Garcia

 Applied Math, Physics and CS
2017 NYS Secondary Math PAEMST Nominee

Sage Ebay

Wednesday, March 22, 2017

CIS(theta), 2016-2017: March Meeting: MPI4PY +!

CIS(theta), 2016-2017: 
March Meeting: MPI4PY +!

Before going on to 
Step 7: Coding 1 - Quadrature, 
we decided to install mpi4py and to write the programs and to test the cluster using python! 

So we added a new
Step 6: Software Stack III - MPI4PY
(see below).

InstantCluster Step 1: 
Infrastructure - Power, Wiring and AC

InstantCluster Step 2: 
Hardware - PCs

InstantCluster Step 3: 
Firmware - Ubuntu

InstantCluster Step 4: 
Software Stack I - openSSH:

01) Install openSSH-server from USC or

02) Create a the same new user on every box of the cluster

03) login as the new user, we used 
userid: jaeger, passwd: galaga

04) If you have no .ssh directory in your home directory, ssh to some other machine in the lab; then Ctrl-d to close the connection, creating .ssh and some related files. 

05) From your home directory, make .ssh secure by entering:
chmod 700 .ssh

06) Next, make .ssh your working directory by entering:
cd .ssh

07) To list/view the contents of the directory, enter:
ls -a [we used ls -l]

08) To generate your public and private keys, enter:
ssh-keygen -t rsa

The first prompt is for the name of the file in which your private key will be stored; press Enter to accept the default name (id_rsa).The next two prompts are for the password you want, and since we are trying to avoid entering passwords, just press Enter at both prompts, returning you to the system prompt.

09) To compare the previous output of ls and see what new files have been created, enter:
ls -a [we used ls -l]
You should see id_rsa containing your private key, and containing your public key.

10) To make your public key the only thing needed for you to ssh to a different machine, enter:
cat >> authorized_keys

NOTE: The Linux boxes on our LAN, soon to be cluster, have IPs ranging from to So, we copied each file to temp01-temp24 and uploaded these files via ssh to the teacher station. Then we just ran cat tempnn >> authorized_keys for each temp file to generate one master authorized_keys file for all nodes that we could just download to each node's .ssh dir.

[optional] To make it so that only you can read or write the file containing your private key, enter:
chmod 600 id_rsa 

[optional] To make it so that only you can read or write the file containing your authorized keys, enter: 
chmod 600 authorized_keys

InstantCluster Step 5: 
Software Stack II - openMPI

We finally have openSSH installed with public key authentication on We tested that today.
Today we also installed openmpi-bin, libopenmpi-dev and gfortran on the same machines: 

sudo apt-get install openmpi-bin
sudo apt-get install libopenmpi-dev
sudo apt-get install gfortran

Then we compiled flops.f:

mpif77 -o flops flops.f

Then we ran flops on our quadcores:

mpirun -np 4 flops

We got about 8 GFLOPS! So, we have multicore working on individual PCs now it's time scale our job over the cluster! 

mpirun -np 16 --hostfile machines flops

We got up to nearly 32GFLOPS! We made sure all four PCs are identical COTS, have identical firmware, have public key authenticated ssh for the user jaeger, and have these 3 files:


The /home/jaeger/machines file is a txt file that looks like this:

InstantCluster Step 6: 
Software Stack III - MPI4PY +

python is a very easy language to learn. It's an interpreted language, so all you have to do is write a text file and run it through the python interpreter as long as it's installed (we have it in unbuntu). is just one line (unlike java): print "hello!" 

Save this line to a file called with your fave text editor and that's it! Or you could call it since it's a sequential, not a MPI, script. 

To run it, open a shell and type:


Alternatively, you could add a line at the top of #!/usr/bin/python or whatever path points to your installation of python. Then make the file executable and run it from the commandline as the super user in a terminal:

chmod 755

Then we installed "python-mpi4py" as the main user from 

Make sure to install that package on every linux box in the cluster. Our looks like this:

import sys
from mpi4py import MPI

id = comm.Get_rank()
name = MPI.Get_processor_name()

if id==0:
  print "This is id=0, I am the Master Process!"
  print "HELLO_MPI: there are ", p, " MPI processes running."
print "Hello World, from process: ", id
print "Hello World, my name is ", name

The first line is probably optional as you are going to run this file using mpirun on one PC (quadcore):

mpirun -np 4 python

or on the whole cluster (4 quadcores):

mpirun -np 16 --hostfile machines python

After you edit and save, before running mpirun, make sure to:

scp jaeger@10.5.129.XXX:/

making an identical copy of the file in the home folder of every PC in the cluster. That's it, you have a working MPI cluster using python!

We are also studying sample MPI code:

InstantCluster Step 7: 
Coding I - Quadrature

InstantCluster Step 8: 
Coding II - Mandelbrot

InstantCluster Step 9: 
Coding III - Mandel Zoom

InstantCluster Step 10: 
Coding IV - POVRay

InstantCluster Step 11: 
Coding V - Blender

InstantCluster Step 12: 
Coding VI - 3D Animation

09/14/2016 (organizational meeting)
10/26/2016 (installing Ubuntu 16.10 64bit)
11/09/2016 (installing Ubuntu 16.10 64bit)
12/14/2016 (Pelican HPC DVD)
01/11/2017 (openSSH Public Keys)
02/08/2017 (openMPI Software Stack)
03/08/2017 (Quadrature)
03/22/2017 (Fractal Plots + Zoom Movie)
(03/29/2017 is a make up day)
04/26/2017 (POVRAY 3D Stills + Animation)
05/10/2017 (Blender 3D Animation)
(05/24/2017 is a make up day)

So, what's all this good for aside from making a Fractal Zoom or Shrek Movie?

SETI Search
Protein Folding
Beal Conjecture
Scientific Computing
Computational Physics
Mersenne Prime Search
Computational Chemistry
Computational Astronomy
Computer Aided Design (CAD)
Computer Algebra Systems (CAS)

These are but a few examples of using Computer Science to solve problems in Mathematics and the Sciences (STEAM). In fact, many of these applications fall under the heading of Cluster Programming or Super Computing. These problems typically take too long to process on a single PC, so we need a lot more horse power. Next time, maybe we'll just use Titan!


Membership (alphabetic by first name):
CIS(theta) 2016-2017: 
DanielD(12), JevanyI(12), JuliaL(12), MichaelC(12) , MichaelS(12), YaminiN(12)

CIS(theta) 2015-2016: 
BenR(11), BrandonL(12), DavidZ(12), GabeT(12), HarrisonD(11), HunterS(12), JacksonC(11), SafirT(12), TimL(12)

CIS(theta) 2014-2015: 
BryceB(12), CheyenneC(12), CliffordD(12), DanielP(12), DavidZ(12), GabeT(11), KeyhanV(11), NoelS(12), SafirT(11)

CIS(theta) 2013-2014: 
BryanS(12), CheyenneC(11), DanielG(12), HarineeN(12), RichardH(12), RyanW(12), TatianaR(12), TylerK(12)

CIS(theta) 2012-2013: 
Kyle Seipp(12)

CIS(theta) 2011-2012: 
Graham Smith(12), George Abreu(12), Kenny Krug(12), LucasEager-Leavitt(12)

CIS(theta) 2010-2011: 
David Gonzalez(12), Herbert Kwok(12), Jay Wong(12), Josh Granoff(12), Ryan Hothan(12)

CIS(theta) 2009-2010: 
Arthur Dysart(12), Devin Bramble(12), Jeremy Agostino(12), Steve Beller(12)

CIS(theta) 2008-2009: 
Marc Aldorasi(12), Mitchel Wong(12)

CIS(theta) 2007-2008: 
Chris Rai(12), Frank Kotarski(12), Nathaniel Roman(12)

CIS(theta) 1988-2007: 
A. Jorge Garcia, Gabriel Garcia, James McLurkin, Joe Bernstein, ... too many to mention here!

Well, that's all folks,
A. Jorge Garcia

 Applied Math, Physics and CS
2017 NYS Secondary Math PAEMST Nominee

Sage Ebay