This statement started off as a paragraph or two in the early threads... - Very worrying report: Supreme Leader Khameini has called for Friday Prayers where he will be present. There are fears that the IRG is going to have a massive presence and that this might be a trap, but on the other hand not attending makes the reformists enemies of Islam and worthy of the death penalty. There are also reports that other Reformist candidate Karoubi and his entire party leadership were arrested.
Nothing much has happened in the last hours aside of that. There are reports of clerics and ayatollahs meeting in the holy Shiite city of Qom in order to plan to overthrow Khameini as supreme leader, as well as a more and more pro-dissenters stance from the army, but we have nothing substantiated so far. I will yet update this tomorrow, adding further information about various other groups operating in Iran right now and relevant to this revolution.
I really am trying to cram the most relevant information and speculation only. Everything is updated as events unfold, especially the timeline and what will happen in the future. If you want to link this, here is the website, updated as the situation changes:
All twitter posts about the army being involved are false as I am writing this Warning, new twitter feeds are most likely government members trying to spread misinformation, ignore them! Also, there is a handful of good twitter feeds, but please do not publicize their usernames, they are in enough danger as it is and they don't need more publiclity. Those in the know will c/p their entries. Major timeline overhaul, including what has unfolded in the last few hours.
Suppression of Dissent - The Players
Currently, there are either two or three groups who are suppressing the students on the ground that you'll read about throughout this thread:
1. The Basij 2. Ansar Hizbullah (which I will refer to as Ansar) 3. Lebanese Hizbullah (Unconfirmed but highly probable. Der Spiegel, based on a Voice of America report, says that 5,000 Hizbullah fighters are currently in Iran masquerading as riot police, confirming the independent reports. Many different independent reports and video point that way. Even in the last hours other independent twitter feeds have declared witnessing thugs beating on people while shouting in Arabic; I will refer to them as Hizbullah)
- The Basij are your regular paramilitary organization. They are the armed hand of the clerics. The Basij are a legal group, officially a student union, and are legally under direct orders of the Revolutionary Guard. Their main raison d'Ãtre is to quell dissent. They are the ones who go and crack skulls, force people to participate in pro-regime demonstrations, and generally try to stop any demonstrations from even starting. They are located throughout the country, in every mosque, every university, every social club you can think of. They function in a way very similar to the brownshirts.
They were the ones who first started the crackdown after the election, but it wasn't enough. While they are violent and repressive, they are still Persian and attacking fellow citizens. A beating is one thing, mass killings another.
- Another group was working with them, whose members are even more extreme, is Ansar. There is a lot of cross-membership between the Basij and Ansar, though not all are members of the other group and vice-versa. The vast majority of Ansar are Persians (either Basij or ex-military), though a lot of Arab recruits come from Lebanon and train with them under supervision of the Revolutionary Guard. They are not functioning under a legal umbrella, they are considered a vigilante group, but they pledge loyalty directly to the Supreme Leader and most people believe that they are under his control. They are currently helping the Basij to control the riots, but due to the fact that they are Persians and i
Sign up for twitter. Change your Time Zone and Location to Tehran.
Re twitter stuff from trusted sources, paraphrasing it and not attributing it to them. It'll make it harder and jack up the noise of people looking for the actual tweeters.
E-mail CNN, MSNBC, NBC, CBS etc and ask them why this isn't being covered more.
I imagine the worst problem right now (and I've seen it first hand), is people that think they're helping but don't forward the ports, so they e-mail people the IP and it takes time to verify that what they setup is/was useless.
Not long after the first requests for proxies went out, went out the requests for "So how do I configure this again?".
So I created ProxyBox[mirror] to help people get stuff setup quickly. It has squid (listening on a multitude of ports), tor, & ziproxy. It was quick and dirty (and the file size shows). Not to mention I'm just a Mechanical Engineer, not a security expert. This was meant for the fark crowd and not for the slashdot, I'm sure everyone here is more than capable of setting up some proxies.
Austin Heap has been distributing the Proxies to Iranians on the inside via twitter and such. (Twitter) his biggest problem right now is ssh servers inside of Iran to make sure that proxies work. Supposedly he's also been able to set up VPNs on fast connections. But work is slow because the internet is slow and he's down to 1-2 SSH boxes ATM.
They've already started blocking ports 80,81, 3128 & 8080. And starting to send fake RESETs on TCP connections (Comcast anyone?).
How you can help: Well I'd like some help making ProxyBox a ton smaller. If DSL can get a full GUI in 50MB, there's no reason ProxyBox should be 400MB. I'd also like to turn it into a LiveCD or LiveUSB so it can be set up by anyone not just with VirtualBox. (jjarvis98 at gmail.com)
Tor is being used quite extensively. Some people have setup exit nodes and had their connections filled with people hitting nothing more than twitter, facebook & youtube. Set up an exit node or bridge if nothing else.
Proxies: Squid installed and listening on ports: 7, 13, 53, 993, 995, 3128 Polipo installed and listening on port: 8123. Polipo is routed through Tor. Tor: port 9050 (a socks5 proxy) Ziproxy: Port 8080 (good for low bandwidth connections. It recompress images & text. Socat: Must be run manually, but listens on port 443 and routes through Squid.
SSH enabled, listening on ports 22,80,2222,22222 2 Users: root:#iran and iran:election. If you enable ssh to the world, change the root password (passwd). This should enable ssh tunneling. - I created this for people on Fark who were having problems with squid. Everyone here shouldn't have a problem. It's a bare bones (netinst) debian install with all the above installed and setup.
I did NOT put ACLs in because there are reports here: http://iran.sharearchy.com/ that the ACL list is actually blocking some people in Iran.
And could one of the mods please change to the coral cache of Austin's website? He's already getting DDoS'd by Iran all this morning. Slashdot isn't going to help anything.
If any/.ers would like to help make it smaller, better, faster (VPN?), jjarvis98 at gmail.com
And you're free to inspect it to make sure I'm not trying to r00t you.
Again, this is just something I thew together last night when people on Fark (VII threads and counting) were wanting to help but not able to figure out squid.
I would appreciate any feedback or help hardening it or adding features or getting the download size down or etc...
Or browse like the Iranians. There's currently a pretty decent number of people helping set up proxies around the world for use in Iran. Austin Heap managed to setup some VPN servers on gigabit-ethernet.
I'm working on a Virtual Appliance that runs Squid, Tor, Polipo+Tor, ziproxy & ssh for use by people who don't quite know how to setup squid for themselves or want to sandbox it.
My first two went like that. Then I tried keeping them on the line as LONG as possible.
The operators they got were some quick talkers. I raised a very very specific issue with my car and he knew about ALL of them. He knew other people asked about that exact same thing. You also had to know the right buzz words (75k miles. 2-4 years old, etc).
After I got past level 1 I started giving them VINs from stuff I found on Auto Trader. It was a crap shoot on how long I lasted after that.
So until any other company used it, the first USB port on a computer was proprietary? So until any other company used it, the first PCI port on a computer was proprietary? So until any other company used it, the first firewire port on a computer was proprietary? So until any other company used it, the first X port on a computer was proprietary?
http://en.wikipedia.org/wiki/Proprietary The word proprietary indicates that a party, or proprietor, exercises private ownership, control or use over an item of property.
http://dictionary.reference.com/browse/proprietary 1. belonging to a proprietor. 2. being a proprietor; holding property: the proprietary class. 3. pertaining to property or ownership: proprietary wealth. 4. belonging or controlled as property. 5. manufactured and sold only by the owner of the patent, formula, brand name, or trademark associated with the product: proprietary medicine. 6. privately owned and operated for profit: proprietary hospitals.
(Mini) Display Port is NOT proprietary. Dell uses Display Port. Other laptop or netbook companies may find a mini display port smaller than VGA. Only time will tell.
DisplayPort IS an open standard. Mini Display Port is added to the 1.2 specification. You can look up all the wiring for the pins, making IT NOT PROPRIETARY.
Apple was literally the first company to put these out. So for a short time there was only 1 place to buy them.
You can get cables from Monoprice and any of a dozen online retailers. Right now you can get DisplayPort connectors from DigiKey and I imagine once 1.2 is fully adopted , that you'll probably have no problem finding Mini DisplayPort connectors at Digikey.
Again, how is (Mini) Display Port any more proprietary than VGA, DVI, HDMI?
If the spec is open, isn't it, by definition, not proprietary?
It's like claiming Linux is proprietary because you down have GCC? The Spec is open. No patents or licenses are preventing you from making your own display port. You just don't have the means necessary.
Heck, by that 'definition' VGA, DVI, etc are all "proprietary" too. Just because you can't make it or buy it at best buy, doesn't mean that it's proprietary.
Now, bow your elbows out. Notice how that relieves the tension.
I sit and type such that my hands are at an angle that if I extend my index fingers and thumbs I form a triangle. No tension what so ever. The only downside is I need a bit of elbow room (no comfortable typing on an airplane).
My ODE I & II courses let you use Maple & a Calculator. There were 2 parts to the test. A Maple part and a calculator part.
Every one I tell this to from a different school thinks that the tests must have been the easiest ones in the world, quite the opposite. You actually had to have a grasp of the point of ODEs.
Meaning instead of x''+2x'+x'=y'' x(0)=4, etc It was "the rate of which the rabbit population changes is based on the rate of the population of wolves. Rabbits breed this fast, wolves breed this fast. Find equilibrium".
I wouldn't have been able to do as well in HS if I didn't have a calculator. I was a very solid B student all because of my dyslexia. All I needed was a basic solar one and I made it through even Calc 100x better. Something about punching numbers in instead of writing them down.
Messaging 1500 Message any way, to anyone in the U.S. Send and receive 1500 text, picture, video, and Instant Messaging (IM) messages. Additional messages are 5 cents each.
i=1:10000; (1 to 10000 in 1 increments) i=1:0.1:100; (1 to 100 in 0.1 increments)
y=sin(pi.*i/10). (.* means do it element wise, same with./.^)
For Loop: Elapsed time is 44.225897 seconds. For Loop (pre allocated): Elapsed time is 0.011962 seconds. Matrix Algebra: Elapsed time is 0.007736 seconds.*
So now that you can see that pre-allocation for loops are much faster, I'm dropping the non-allocated (I don't have all day).**
i increased to 1E5 For Loop (Pre-allocated): 2.1s Matrix Algebra:.7s
That 1.4s adds up if you're doing a lot of data.
*Code clear;clc; i=1:0.01:1E3; tic for j=1:size(i,2) y(j)=sin(pi*i(j)/10); end toc;tic y2=zeros(size(i)); for j=1:size(i,2) y2(j)=sin(pi*i(j)/10); end toc;tic y3=sin(pi.*i/10); toc;
I did the exact same thing. I elected to take CS120 after ME123 after I got the highest grade in the class. Sadly I outscored most "CS" students in CS120. (I'm just a dumb ME, right?). And again with CS240 (C/C++) at Purdue.
For me, it was my first exposure to 'for' and 'while' loops. Most of us didn't have any CS in HS. The only programming I had ever done was for my TI-89 in high school. The biggest help was the fact that all the documentation was right there. 'help' and 'lookfor' were the commands I called the most (and still do). If I want to know how to do eigenvalues, all I have to do is 'lookfor eigen' from Matlab and it'll give me every command with the word 'eigen' in it or the description.
In my experience, most of the ME's did find the class useless. There were still people that didn't grasp the basic concept of loops, functions etc. Their.m script would be a single file with the same code that 'worked' 360 times.
For me, it opened the world of programming, mechatronics and how you fit ME (dynamics, thermo, etc) into it. I have a near recession proof job because of it. (Given the option would you hire a CS that didn't know how the 'mechanical' world worked, an ME that couldn't program or someone that could do both?).
Thankfully CANape scripting is almost identical to C.
As I said above matlab is wonderful at matrices. Even if I prototype code with for loops, I'll convert for 'production'.
Consider the following 2 statements with identical output: x=rand(1,1E5); y=rand(1,1E5); for i=1:size(x,2) z(i)=2*x(i)+y(i)^2+x(i)*y(i); end z2=2.*x+y.^2+x.*y;
How much longer would you think the for loop took? The answer is 24000x. (42.4s vs 0.001761s). QUIT USING FOR LOOPS. You can even write your functions to accept matrices.
If you HAVE to use for loops, preallocate your arrays. z=zeros(size(x)); for i=1:size(x,2) z(i)=2*x(i)+y(i)^2+x(i)*y(i); end
Takes 0.5 seconds. Not as fast as not using matrix algebra, but a hell of a lot faster than just using for loops.
2) Only load what you need. If you're analyzing a 2GB file from an eDaq (edaq.com), only load the channels you're going to use. If you're analyzing data for stability control, there's no reason to read cabin temperature.
Not only will it load multiple times faster (over networks especially) but you'll reduce memory overhead.
We use matlab to crunch terabytes of data. Usually one off scripts designed to find a rare condition or event in the field. It doesn't take long to go through all the data.
I just wish it had a bit more C in it, the thing that gets me the most is when I try to do a i++ and it bombs.
Matlab stops being a 'slow' language once you learn how to use it.
Matlab stands for MATtrix LABoratory. It loves to do matrix algebra more than any other kind. The worst offenders I see are people that try to use for loops for everything.
for i=1:10
y(i)=sin(i); end
is much slower than:
y=sin(1:10).
And it just scales up from there. There were only a very few times I've ever had to use for loops and that's because of memory issues (on Win32).
Unless your current state depends on the previous one, there is no reason to use a for loop. - I never learned FORTRAN, but I make my living on Matlab. Matlab is good for quick turn around. If I need to make a script NOW that does X for me, I can turn it around in a few minutes. No compiling, etc. If I really want speed, I can write MEX (compiled) code.
They're not expensive if you use them and amortized over quite a few years. I went to a Catholic elementary school. ALL of our books were hand-me-downs of Public school books and at least 2-3 editions old.
Unless I haven't been paying attention, Geometry, Calculus, WWII, the Roman Empire, Mitosis, etc hasn't changed much in the last few years. We were also required to have all books covered. They last quite a bit longer if you do this. I know that when I switched to a public school I had the EXACT same history book, it just happened to be 2 editions newer. Other than a few minor editorial changes, I didn't see anything different to my 7th grade mind.
The problem isn't that books are expensive, it's that they keep buying new ones when the old ones aren't obsolete. Moving online isn't going to help unless they use OSS textbooks. Book publishers are going to love this. Instead of buying a book every year for 120$ they're going to give you a wonderful discount of an online book every year for only 50$.
Use the books until covers are falling off. Mandate that book publishers MUST keep publishing an edition X years after it is first published. This will eliminate 'prebuys' to try and cover all books that are expected to be lost or damaged. It'll also let a school use the same book for 10, 15 years. A $100 text book over 15 years isn't too expensive.
Unfortunately 10-15 years is at least one election cycle and everyone will forget what the person they replaced did and it'll be all shiny text books for all "please think of the Children".
Slashdot Mirror
Livers are like starfish. You can hack them apart and they regrow. Heck, here is a story about a split liver helping 2 people.
You can also partially remove some from a living person (Lisa?) and give it to someone.
Unlike... kidneys, lungs, hearts, etc.
Virtualize it!
Seriously. VirtualBox-Mainframe edition has to be out by now. Run it a MacMini hidden in someones mailbox. No one will know the difference.
This statement started off as a paragraph or two in the early threads...
-
Very worrying report: Supreme Leader Khameini has called for Friday Prayers where he will be present. There are fears that the IRG is going to have a massive presence and that this might be a trap, but on the other hand not attending makes the reformists enemies of Islam and worthy of the death penalty. There are also reports that other Reformist candidate Karoubi and his entire party leadership were arrested.
Nothing much has happened in the last hours aside of that. There are reports of clerics and ayatollahs meeting in the holy Shiite city of Qom in order to plan to overthrow Khameini as supreme leader, as well as a more and more pro-dissenters stance from the army, but we have nothing substantiated so far. I will yet update this tomorrow, adding further information about various other groups operating in Iran right now and relevant to this revolution.
I really am trying to cram the most relevant information and speculation only. Everything is updated as events unfold, especially the timeline and what will happen in the future. If you want to link this, here is the website, updated as the situation changes:
https://sites.google.com/site/tatsumairanupdate/
All twitter posts about the army being involved are false as I am writing this Warning, new twitter feeds are most likely government members trying to spread misinformation, ignore them! Also, there is a handful of good twitter feeds, but please do not publicize their usernames, they are in enough danger as it is and they don't need more publiclity. Those in the know will c/p their entries. Major timeline overhaul, including what has unfolded in the last few hours.
Suppression of Dissent - The Players
Currently, there are either two or three groups who are suppressing the students on the ground that you'll read about throughout this thread:
1. The Basij
2. Ansar Hizbullah (which I will refer to as Ansar)
3. Lebanese Hizbullah (Unconfirmed but highly probable. Der Spiegel, based on a Voice of America report, says that 5,000 Hizbullah fighters are currently in Iran masquerading as riot police, confirming the independent reports. Many different independent reports and video point that way. Even in the last hours other independent twitter feeds have declared witnessing thugs beating on people while shouting in Arabic; I will refer to them as Hizbullah)
- The Basij are your regular paramilitary organization. They are the armed hand of the clerics. The Basij are a legal group, officially a student union, and are legally under direct orders of the Revolutionary Guard. Their main raison d'Ãtre is to quell dissent. They are the ones who go and crack skulls, force people to participate in pro-regime demonstrations, and generally try to stop any demonstrations from even starting. They are located throughout the country, in every mosque, every university, every social club you can think of. They function in a way very similar to the brownshirts.
They were the ones who first started the crackdown after the election, but it wasn't enough. While they are violent and repressive, they are still Persian and attacking fellow citizens. A beating is one thing, mass killings another.
- Another group was working with them, whose members are even more extreme, is Ansar. There is a lot of cross-membership between the Basij and Ansar, though not all are members of the other group and vice-versa. The vast majority of Ansar are Persians (either Basij or ex-military), though a lot of Arab recruits come from Lebanon and train with them under supervision of the Revolutionary Guard. They are not functioning under a legal umbrella, they are considered a vigilante group, but they pledge loyalty directly to the Supreme Leader and most people believe that they are under his control. They are currently helping the Basij to control the riots, but due to the fact that they are Persians and i
Sign up for twitter.
Change your Time Zone and Location to Tehran.
Re twitter stuff from trusted sources, paraphrasing it and not attributing it to them. It'll make it harder and jack up the noise of people looking for the actual tweeters.
E-mail CNN, MSNBC, NBC, CBS etc and ask them why this isn't being covered more.
DO NOT USE HIS ACTUAL DOMAIN.
http://blog.austinheap.com.nyud.net:8080/
He's been getting DDoS'd from IRAN and other sources long before people posted his web page on slashdot.
This site also has a bit cleaner information. http://iran.sharearchy.com.nyud.net:8080
I imagine the worst problem right now (and I've seen it first hand), is people that think they're helping but don't forward the ports, so they e-mail people the IP and it takes time to verify that what they setup is/was useless.
Not long after the first requests for proxies went out, went out the requests for "So how do I configure this again?".
So I created ProxyBox [mirror] to help people get stuff setup quickly. It has squid (listening on a multitude of ports), tor, & ziproxy. It was quick and dirty (and the file size shows). Not to mention I'm just a Mechanical Engineer, not a security expert. This was meant for the fark crowd and not for the slashdot, I'm sure everyone here is more than capable of setting up some proxies.
Austin Heap has been distributing the Proxies to Iranians on the inside via twitter and such. (Twitter) his biggest problem right now is ssh servers inside of Iran to make sure that proxies work. Supposedly he's also been able to set up VPNs on fast connections. But work is slow because the internet is slow and he's down to 1-2 SSH boxes ATM.
They've already started blocking ports 80,81, 3128 & 8080. And starting to send fake RESETs on TCP connections (Comcast anyone?).
How you can help:
Well I'd like some help making ProxyBox a ton smaller. If DSL can get a full GUI in 50MB, there's no reason ProxyBox should be 400MB. I'd also like to turn it into a LiveCD or LiveUSB so it can be set up by anyone not just with VirtualBox. (jjarvis98 at gmail.com)
Tor is being used quite extensively. Some people have setup exit nodes and had their connections filled with people hitting nothing more than twitter, facebook & youtube. Set up an exit node or bridge if nothing else.
Supposedly UDP and ping still work fine. So some people are looking into TCP over UDP or I was also thinking about Ping Tunnel (Tcp over Ping)
#irantech on irc.freenode.net is a bit unorganized but it's working for now.
Mirror 1
Mirror 2
Proxies:
Squid installed and listening on ports: 7, 13, 53, 993, 995, 3128
Polipo installed and listening on port: 8123. Polipo is routed through Tor.
Tor: port 9050 (a socks5 proxy)
Ziproxy: Port 8080 (good for low bandwidth connections. It recompress images & text.
Socat: Must be run manually, but listens on port 443 and routes through Squid.
SSH enabled, listening on ports 22,80,2222,22222
2 Users: root:#iran and iran:election. If you enable ssh to the world, change the root password (passwd). This should enable ssh tunneling.
-
I created this for people on Fark who were having problems with squid. Everyone here shouldn't have a problem. It's a bare bones (netinst) debian install with all the above installed and setup.
I did NOT put ACLs in because there are reports here: http://iran.sharearchy.com/ that the ACL list is actually blocking some people in Iran.
And could one of the mods please change to the coral cache of Austin's website? He's already getting DDoS'd by Iran all this morning. Slashdot isn't going to help anything.
If any /.ers would like to help make it smaller, better, faster (VPN?), jjarvis98 at gmail.com
And you're free to inspect it to make sure I'm not trying to r00t you.
Imagine if every single person in Iran thought that before they went outside.
I'm just a white collar guy that works 9-5. People asked for proxy servers. People wanted help setting up proxy servers. I did what I could.
I should have just watched American Idol.
My host forgive me. http://www.exstatic.org.nyud.net:8080/proxybox/.
Again, this is just something I thew together last night when people on Fark (VII threads and counting) were wanting to help but not able to figure out squid.
I would appreciate any feedback or help hardening it or adding features or getting the download size down or etc...
jjarvis98@gmail.com
Or browse like the Iranians. There's currently a pretty decent number of people helping set up proxies around the world for use in Iran. Austin Heap managed to setup some VPN servers on gigabit-ethernet.
I'm working on a Virtual Appliance that runs Squid, Tor, Polipo+Tor, ziproxy & ssh for use by people who don't quite know how to setup squid for themselves or want to sandbox it.
My first two went like that. Then I tried keeping them on the line as LONG as possible.
The operators they got were some quick talkers. I raised a very very specific issue with my car and he knew about ALL of them. He knew other people asked about that exact same thing. You also had to know the right buzz words (75k miles. 2-4 years old, etc).
After I got past level 1 I started giving them VINs from stuff I found on Auto Trader. It was a crap shoot on how long I lasted after that.
So until any other company used it, the first USB port on a computer was proprietary?
So until any other company used it, the first PCI port on a computer was proprietary?
So until any other company used it, the first firewire port on a computer was proprietary?
So until any other company used it, the first X port on a computer was proprietary?
http://en.wikipedia.org/wiki/Proprietary
The word proprietary indicates that a party, or proprietor, exercises private ownership, control or use over an item of property.
http://dictionary.reference.com/browse/proprietary
1. belonging to a proprietor.
2. being a proprietor; holding property: the proprietary class.
3. pertaining to property or ownership: proprietary wealth.
4. belonging or controlled as property.
5. manufactured and sold only by the owner of the patent, formula, brand name, or trademark associated with the product: proprietary medicine.
6. privately owned and operated for profit: proprietary hospitals.
(Mini) Display Port is NOT proprietary. Dell uses Display Port. Other laptop or netbook companies may find a mini display port smaller than VGA. Only time will tell.
DisplayPort IS an open standard. Mini Display Port is added to the 1.2 specification. You can look up all the wiring for the pins, making IT NOT PROPRIETARY.
Apple was literally the first company to put these out. So for a short time there was only 1 place to buy them.
You can get cables from Monoprice and any of a dozen online retailers. Right now you can get DisplayPort connectors from DigiKey and I imagine once 1.2 is fully adopted , that you'll probably have no problem finding Mini DisplayPort connectors at Digikey.
Again, how is (Mini) Display Port any more proprietary than VGA, DVI, HDMI?
If the spec is open, isn't it, by definition, not proprietary?
It's like claiming Linux is proprietary because you down have GCC? The Spec is open. No patents or licenses are preventing you from making your own display port. You just don't have the means necessary.
Heck, by that 'definition' VGA, DVI, etc are all "proprietary" too. Just because you can't make it or buy it at best buy, doesn't mean that it's proprietary.
Now, bow your elbows out. Notice how that relieves the tension.
I sit and type such that my hands are at an angle that if I extend my index fingers and thumbs I form a triangle. No tension what so ever. The only downside is I need a bit of elbow room (no comfortable typing on an airplane).
Windows Media Player... now goes to 11.
I mean that sucks me right in. If there's anything that's funny, it's a quote from a 25 year old movie.
Way to go Microsoft Marketing.
I want to know who setup twits as signed. Are there going to be negative twits? Twits by your evil twin?
THINK about what your code does and choose the appropriate data type.
My ODE I & II courses let you use Maple & a Calculator. There were 2 parts to the test. A Maple part and a calculator part.
Every one I tell this to from a different school thinks that the tests must have been the easiest ones in the world, quite the opposite. You actually had to have a grasp of the point of ODEs.
Meaning instead of x''+2x'+x'=y'' x(0)=4, etc
It was "the rate of which the rabbit population changes is based on the rate of the population of wolves. Rabbits breed this fast, wolves breed this fast. Find equilibrium".
I wouldn't have been able to do as well in HS if I didn't have a calculator. I was a very solid B student all because of my dyslexia. All I needed was a basic solar one and I made it through even Calc 100x better. Something about punching numbers in instead of writing them down.
From AT&T's website:
Messaging 1500
Message any way, to anyone in the U.S. Send and receive 1500 text, picture, video, and Instant Messaging (IM) messages. Additional messages are 5 cents each.
The difference is "unlimited" vs unlimited.
If you read through the "unlimited" for home use is "*unlimited based on our internal estimation of how much a home user should use per month".
The corporate unlimited is truly unlimited.
Not a stupid tax, but just as deceptive.
How big do you want i?
./ .^)
.7s
i=1:10000; (1 to 10000 in 1 increments)
i=1:0.1:100; (1 to 100 in 0.1 increments)
y=sin(pi.*i/10).
(.* means do it element wise, same with
For Loop: Elapsed time is 44.225897 seconds.
For Loop (pre allocated): Elapsed time is 0.011962 seconds.
Matrix Algebra: Elapsed time is 0.007736 seconds.*
So now that you can see that pre-allocation for loops are much faster, I'm dropping the non-allocated (I don't have all day).**
i increased to 1E5
For Loop (Pre-allocated): 2.1s
Matrix Algebra:
That 1.4s adds up if you're doing a lot of data.
*Code
clear;clc;
i=1:0.01:1E3;
tic
for j=1:size(i,2)
y(j)=sin(pi*i(j)/10);
end
toc;tic
y2=zeros(size(i));
for j=1:size(i,2)
y2(j)=sin(pi*i(j)/10);
end
toc;tic
y3=sin(pi.*i/10);
toc;
I did the exact same thing. I elected to take CS120 after ME123 after I got the highest grade in the class. Sadly I outscored most "CS" students in CS120. (I'm just a dumb ME, right?). And again with CS240 (C/C++) at Purdue.
For me, it was my first exposure to 'for' and 'while' loops. Most of us didn't have any CS in HS. The only programming I had ever done was for my TI-89 in high school. The biggest help was the fact that all the documentation was right there. 'help' and 'lookfor' were the commands I called the most (and still do). If I want to know how to do eigenvalues, all I have to do is 'lookfor eigen' from Matlab and it'll give me every command with the word 'eigen' in it or the description.
In my experience, most of the ME's did find the class useless. There were still people that didn't grasp the basic concept of loops, functions etc. Their .m script would be a single file with the same code that 'worked' 360 times.
For me, it opened the world of programming, mechatronics and how you fit ME (dynamics, thermo, etc) into it. I have a near recession proof job because of it. (Given the option would you hire a CS that didn't know how the 'mechanical' world worked, an ME that couldn't program or someone that could do both?).
Thankfully CANape scripting is almost identical to C.
As I said above matlab is wonderful at matrices. Even if I prototype code with for loops, I'll convert for 'production'.
Consider the following 2 statements with identical output:
x=rand(1,1E5);
y=rand(1,1E5);
for i=1:size(x,2)
z(i)=2*x(i)+y(i)^2+x(i)*y(i);
end
z2=2.*x+y.^2+x.*y;
How much longer would you think the for loop took? The answer is 24000x. (42.4s vs 0.001761s). QUIT USING FOR LOOPS. You can even write your functions to accept matrices.
If you HAVE to use for loops, preallocate your arrays.
z=zeros(size(x));
for i=1:size(x,2)
z(i)=2*x(i)+y(i)^2+x(i)*y(i);
end
Takes 0.5 seconds. Not as fast as not using matrix algebra, but a hell of a lot faster than just using for loops.
2) Only load what you need. If you're analyzing a 2GB file from an eDaq (edaq.com), only load the channels you're going to use. If you're analyzing data for stability control, there's no reason to read cabin temperature.
data=load('data.mat','yaw','pitch','roll','throttle')
Not only will it load multiple times faster (over networks especially) but you'll reduce memory overhead.
We use matlab to crunch terabytes of data. Usually one off scripts designed to find a rare condition or event in the field. It doesn't take long to go through all the data.
I just wish it had a bit more C in it, the thing that gets me the most is when I try to do a i++ and it bombs.
Matlab stops being a 'slow' language once you learn how to use it.
Matlab stands for MATtrix LABoratory. It loves to do matrix algebra more than any other kind. The worst offenders I see are people that try to use for loops for everything.
for i=1:10
y(i)=sin(i);
end
is much slower than:
y=sin(1:10).
And it just scales up from there. There were only a very few times I've ever had to use for loops and that's because of memory issues (on Win32).
Unless your current state depends on the previous one, there is no reason to use a for loop.
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I never learned FORTRAN, but I make my living on Matlab. Matlab is good for quick turn around. If I need to make a script NOW that does X for me, I can turn it around in a few minutes. No compiling, etc. If I really want speed, I can write MEX (compiled) code.
They're not expensive if you use them and amortized over quite a few years. I went to a Catholic elementary school. ALL of our books were hand-me-downs of Public school books and at least 2-3 editions old.
Unless I haven't been paying attention, Geometry, Calculus, WWII, the Roman Empire, Mitosis, etc hasn't changed much in the last few years. We were also required to have all books covered. They last quite a bit longer if you do this. I know that when I switched to a public school I had the EXACT same history book, it just happened to be 2 editions newer. Other than a few minor editorial changes, I didn't see anything different to my 7th grade mind.
The problem isn't that books are expensive, it's that they keep buying new ones when the old ones aren't obsolete. Moving online isn't going to help unless they use OSS textbooks. Book publishers are going to love this. Instead of buying a book every year for 120$ they're going to give you a wonderful discount of an online book every year for only 50$.
Use the books until covers are falling off. Mandate that book publishers MUST keep publishing an edition X years after it is first published. This will eliminate 'prebuys' to try and cover all books that are expected to be lost or damaged. It'll also let a school use the same book for 10, 15 years. A $100 text book over 15 years isn't too expensive.
Unfortunately 10-15 years is at least one election cycle and everyone will forget what the person they replaced did and it'll be all shiny text books for all "please think of the Children".