I know I am going to come off as a 'shill' but MS tools rock (I am not talking about their frameworks). It is the one thing that holds me to windows these days. All those tools you mention are available in windows and usually better polished. Valgrind compaired to say using boundschecker. You goto valgrind and bisect issues, boundschecker puts you right on the offending line that they think either overwrote memory or leaked..
You're going to come off as an MS shill because you are flat out lying. Valgrind tells you exactly what line is offending.
char *p = malloc(8);
p[10] = 42;
Let valgrind run that code and it will immediately tell you that the source filename and linenumber that p[10]=42; is on along with a callstack backtrace.
Ditto with leaked memory, reads of uninitialized memory etc.
Efficiency matters. Python is great, but you don't want to use it for embedded work.
Actually, I am currently working on an ARM based commercial embedded system that is almost entirely written in Python (on Linux).
Once you make the leap of adding external ram and flash, which you need to run Linux reasonably, using python is not really a big deal.
The whole system is still only a few square cm big; you could hide it in your fist.
Oh - vipw's for wimps./etc/passwd's a text file, designed to be easily maintained by hand. If you can't hand edit it without fucking up, you don't deserve root permissions to the system.
You're not thinking multiuser scenarios.
The main feature of vipw is that it does locking. This prevents two admins from editing/etc/passwd at the same time, which could corrupt it completely.
It also keeps it from getting corrupted because some user happens to be changing their password while/etc/passwd is being edited.
Most questions on calculus tests I've taken don't have numeric answers. "Solve for X" was to be answered with the equation..
My example with a normal calculator above shows how to verify your answer.
As a trivial example, "solve d(x^2)/dx". Well duh, the answer is 2*x, but you can numerically verify that:
Evaluate x^2 at 1 and 1.001. You get 1 and 1.002001. The difference times 1000 then is 2.001.
Now evaluate your answer at 1: You get 2. Yup, your answer is probably right.
Similarly, even the lamest programmable calculator can do numerical integration. So again, just numerically integrate your original function
from 0 to 1 or whatever and verify that your integral answer formula produces a similar number.
I did this quite regularly in calculus exams. Saved my ass repeatedly. You can also plug your test number into your intermediate steps to see where it changes -- that will be the place you made a mistake.
So yes calculators are useful in calculus exams, even if it's not a monster like the HP50g that does full symbolic calculus.
Any sane prof would require that you show your work.
That's fine; the HP50g has a mode where it shows the intermediate steps when solving a calculus problem.
Even if it didn't, don't you think having a device that gives you the correct answer on a silver platter is a pretty handy thing to have in a calculus exam?
That's crazy. Fancy calculators like the HP50g can do symbolic calculus..
Even less fancy calculators can be useful: I used my programmable calculator to check my answers. For a derivative, for example, evaluate the original formula at some arbitrary value, and then again at that same value plus.001. The difference of the results times 1000 is roughly the derivative, so now you can plug that same arbitrary value in your derivative as a confirmation that you probably got the right answer.
The same calculator could also do numeric integration, so integrals could be checked as well.
When I grew up in Sweden, tests were marked with "R" for correct and a checkmark for wrong.
Then we moved to Canada, and one of my first quizzes was math. I took it up to the teacher, who checked off every question and handed the test back to me with a big smile and the exclamation "good!".
I was devastated. I sat at my desk completely baffled as to how I could have gotten every question wrong. I was thinking that maybe math is different in Canada. Eventually I went back to the teacher to complain, and after some confusion we were both sorted out.
So yeah, don't count on checkmark meaning what you think it does to everyone.
Well it could, but it's overkill. The big deal about this thing is that it doesn't distort any magnetic field it's in, making it effectively "invisible" from the magnetic field
If you just want to protect something from a magnetic field and you don't care who knows it, just contain it in something like
mu-metal
Is there some part of "it could be measurement error" that is unclear to you?
I'll just ignore that unnecessary insult.
As I said, I've done tons of undergrad labs and in most all cases of conflict the measuring was the problem.
So your sentence "It could be measurement error, but it's more likely that your models are wrong" is
completely at polar opposites with my experience doing science right in the lab.
Measuring tiny gravity variations while in orbit of a tiny planet in the vicinity of a huge sun with a vicious solar wind, wildly fluctuating magnetic fields and insane temperature variations is not easy. In fact, TFA itself admits that it was very difficult. It would be unprofessional for the modelling crew to not question unusual results. They did, they checked everything over, eventually concluded that the numbers must be good, therefore the model must be adjusted.
"Our geochemistry colleagues kept sending us back to the showers saying 'Your gravity field can't be right because none of the internal structure models are fitting.' But we do now know that we got the gravity field right. It was very difficult."
If the measurements don't fit your models, it doesn't mean the measurements are wrong. It could be measurement error, but it's more likely that your models are wrong. And they call themselves scientists.
So, if you measure neutrinos travelling across Europe faster than the speed of light, then it's most likely that the model that says neutrinos cannot travel faster than the speed of light is wrong?
I did plenty of labs in Physics undergrad days. Almost every time things didn't make sense it turned out to be measurement problems.
To be fair most all of them rent most of their infrastructure from Bell or Rogers, but their policies can be quite different.
For example, my ISP permits me to run servers and is net neutral on their network. Once the packets hit someone else's fiber it's beyond their control of course.
It's not like they have little nanites with cameras crawling around there. Fine, the main thrusters aren't working, but how did they manage to specifically blame it on a piece of rag in a fuel line? Aren't there a lot of ways a thruster can fail to fire?
Ah, sounds like you've been working with lower level stuff then. Any consumer GPS module these days consists of a module smaller than one square cm with serial output that you simply have to parse (plus stuff like a 1 pulse-per-second output pin).
NMEA-0183 is the ASCII protocol used by most marine equipment. GPSes also have a binary protocol which is quite a bit richer.
Anyway, among other things they barf out your lat/lon and the date/time in UTC once per second.
By "the GPS protocol" I meant what is sent OTA from the satellites, which does indeed include UTC correction. In other words, there is
no excuse for a GPS module to not provide a means of giving UTC. And any GPS that produces NMEA-0183 output has no choice but
give corrected UTC time.
The binary SiRF protocol also provides UTC.
And yes the time will be off until you get a fix, but of course you're not supposed to use the timing data until the unit does have a lock.
On 5, 10, 15 or 20 MHz: at 00:00Z you will hear minute consisting of 61 seconds.
If you happen to have a radio controlled timepiece, this will also be your chance to see if they handle the leap second conversion or took the lazy way out and just rely on the next time sync fix the time.
00:00UTC June 30th 2012 is a Saturday evening in North America. What better way to celebrate a Saturday night?
Exactly. Python is completely unusable both in embedded systems, and in anything where performance matters the least little bit.
Since android phone apps have a good chance of being in both categories...
That is complete and utter nonsense. And I say this as an embedded systems developer; we currently have a product that is almost 100% python based. It even runs a webserver in python and the performance is fine. It's a pretty complicated multi-threaded app.
I'm not the only one, either. Only a few months back I was investigating an embedded system, and tons of stuff in it was written in python.
Furthermore, my Symbian S60 smartphone runs python. It actually has some very impressive 3D apps written entirely in python
Python's speed is comparable to any other typical interpreted language.
That is one of the reasons why I find so many FSF supporters to be such hypocrits, they blather on about standards compliance, yet they use and abuse GCC extensions etc. The Linux kernel is horribly tainted in that way.
Crusade: 1706, respelling of croisade (1570s), from M.Fr. croisade (16c.), Sp. cruzada, both from M.L. cruciata, pp. of cruciare "to mark with a cross," from L. crux (gen. crucis) "cross."
The crusades were Christian. Even the name says so. Don't pretend it wasn't.
Gulags were part of Stalinism. So was building dams, rocketry, idiotic agricultural policies, atheism and many other things. Stalin could have been a devout Catholic and still have had Gulags. What is hard to understand about this?
Slashdot Mirror
I know I am going to come off as a 'shill' but MS tools rock (I am not talking about their frameworks). It is the one thing that holds me to windows these days. All those tools you mention are available in windows and usually better polished. Valgrind compaired to say using boundschecker. You goto valgrind and bisect issues, boundschecker puts you right on the offending line that they think either overwrote memory or leaked. .
You're going to come off as an MS shill because you are flat out lying. Valgrind tells you exactly what line is offending.
char *p = malloc(8);
p[10] = 42;
Let valgrind run that code and it will immediately tell you that the source filename and linenumber that p[10]=42; is on along with a callstack backtrace. Ditto with leaked memory, reads of uninitialized memory etc.
Efficiency matters. Python is great, but you don't want to use it for embedded work.
Actually, I am currently working on an ARM based commercial embedded system that is almost entirely written in Python (on Linux).
Once you make the leap of adding external ram and flash, which you need to run Linux reasonably, using python is not really a big deal. The whole system is still only a few square cm big; you could hide it in your fist.
Oh - vipw's for wimps. /etc/passwd's a text file, designed to be easily maintained by hand. If you can't hand edit it without fucking up, you don't deserve root permissions to the system.
You're not thinking multiuser scenarios.
The main feature of vipw is that it does locking. This prevents two admins from editing /etc/passwd at the same time, which could corrupt it completely.
It also keeps it from getting corrupted because some user happens to be changing their password while /etc/passwd is being edited.
Trillions of centuries online, 65.90 thousand centuries with the Massive Cracking Array Scenario, and yet somehow I don't want to use it.
Most questions on calculus tests I've taken don't have numeric answers. "Solve for X" was to be answered with the equation..
My example with a normal calculator above shows how to verify your answer.
As a trivial example, "solve d(x^2)/dx". Well duh, the answer is 2*x, but you can numerically verify that: Evaluate x^2 at 1 and 1.001. You get 1 and 1.002001. The difference times 1000 then is 2.001. Now evaluate your answer at 1: You get 2. Yup, your answer is probably right.
Similarly, even the lamest programmable calculator can do numerical integration. So again, just numerically integrate your original function from 0 to 1 or whatever and verify that your integral answer formula produces a similar number.
I did this quite regularly in calculus exams. Saved my ass repeatedly. You can also plug your test number into your intermediate steps to see where it changes -- that will be the place you made a mistake.
So yes calculators are useful in calculus exams, even if it's not a monster like the HP50g that does full symbolic calculus.
Any sane prof would require that you show your work.
That's fine; the HP50g has a mode where it shows the intermediate steps when solving a calculus problem.
Even if it didn't, don't you think having a device that gives you the correct answer on a silver platter is a pretty handy thing to have in a calculus exam?
That's crazy. Fancy calculators like the HP50g can do symbolic calculus..
Even less fancy calculators can be useful: I used my programmable calculator to check my answers. For a derivative, for example, evaluate the original formula at some arbitrary value, and then again at that same value plus .001. The difference of the results times 1000 is roughly the derivative, so now you can plug that same arbitrary value in your derivative as a confirmation that you probably got the right answer.
The same calculator could also do numeric integration, so integrals could be checked as well.
I saw "GetYourOwnDamnWifi" the other day. Ok guy, I get the point.
. A phone or tablet or reader doesn't need to run Crysis
Perhaps not a phone, but tablets are chiefly recreational devices. Games are part of the market.
It doesn't take much to run Angry Birds.
When I grew up in Sweden, tests were marked with "R" for correct and a checkmark for wrong. Then we moved to Canada, and one of my first quizzes was math. I took it up to the teacher, who checked off every question and handed the test back to me with a big smile and the exclamation "good!".
I was devastated. I sat at my desk completely baffled as to how I could have gotten every question wrong. I was thinking that maybe math is different in Canada. Eventually I went back to the teacher to complain, and after some confusion we were both sorted out.
So yeah, don't count on checkmark meaning what you think it does to everyone.
Yeah, and they've been paying clueless morons to rave about their shit on the internet too.
Well I certainly never saw a dime of that money.
Well it could, but it's overkill. The big deal about this thing is that it doesn't distort any magnetic field it's in, making it effectively "invisible" from the magnetic field
If you just want to protect something from a magnetic field and you don't care who knows it, just contain it in something like mu-metal
Is there some part of "it could be measurement error" that is unclear to you?
I'll just ignore that unnecessary insult.
As I said, I've done tons of undergrad labs and in most all cases of conflict the measuring was the problem. So your sentence "It could be measurement error, but it's more likely that your models are wrong" is completely at polar opposites with my experience doing science right in the lab.
Measuring tiny gravity variations while in orbit of a tiny planet in the vicinity of a huge sun with a vicious solar wind, wildly fluctuating magnetic fields and insane temperature variations is not easy. In fact, TFA itself admits that it was very difficult. It would be unprofessional for the modelling crew to not question unusual results. They did, they checked everything over, eventually concluded that the numbers must be good, therefore the model must be adjusted.
THAT'S what's called being scientists.
"Our geochemistry colleagues kept sending us back to the showers saying 'Your gravity field can't be right because none of the internal structure models are fitting.' But we do now know that we got the gravity field right. It was very difficult."
If the measurements don't fit your models, it doesn't mean the measurements are wrong. It could be measurement error, but it's more likely that your models are wrong. And they call themselves scientists.
So, if you measure neutrinos travelling across Europe faster than the speed of light, then it's most likely that the model that says neutrinos cannot travel faster than the speed of light is wrong?
I did plenty of labs in Physics undergrad days. Almost every time things didn't make sense it turned out to be measurement problems.
There are gobs to choose from: See canadianisp.ca.
To be fair most all of them rent most of their infrastructure from Bell or Rogers, but their policies can be quite different. For example, my ISP permits me to run servers and is net neutral on their network. Once the packets hit someone else's fiber it's beyond their control of course.
It's not like they have little nanites with cameras crawling around there. Fine, the main thrusters aren't working, but how did they manage to specifically blame it on a piece of rag in a fuel line? Aren't there a lot of ways a thruster can fail to fire?
Ah, sounds like you've been working with lower level stuff then. Any consumer GPS module these days consists of a module smaller than one square cm with serial output that you simply have to parse (plus stuff like a 1 pulse-per-second output pin).
NMEA-0183 is the ASCII protocol used by most marine equipment. GPSes also have a binary protocol which is quite a bit richer. Anyway, among other things they barf out your lat/lon and the date/time in UTC once per second.
By "the GPS protocol" I meant what is sent OTA from the satellites, which does indeed include UTC correction. In other words, there is no excuse for a GPS module to not provide a means of giving UTC. And any GPS that produces NMEA-0183 output has no choice but give corrected UTC time.
The binary SiRF protocol also provides UTC.
And yes the time will be off until you get a fix, but of course you're not supposed to use the timing data until the unit does have a lock.
The leap second is at the end of June 30th. From the IERS bulletin:
So be sure to enjoy your extra long Saturday.
The $GPRMC sentence is required by NMEA-0183 to report UTC.
What brand module did you find that did not do this? I'd like to be sure to avoid it...
The GPS protocol includes the UTC offset, so all GPS units report UTC time.
On 5, 10, 15 or 20 MHz: at 00:00Z you will hear minute consisting of 61 seconds.
If you happen to have a radio controlled timepiece, this will also be your chance to see if they handle the leap second conversion or took the lazy way out and just rely on the next time sync fix the time.
00:00UTC June 30th 2012 is a Saturday evening in North America. What better way to celebrate a Saturday night?
Exactly. Python is completely unusable both in embedded systems, and in anything where performance matters the least little bit.
Since android phone apps have a good chance of being in both categories ...
That is complete and utter nonsense. And I say this as an embedded systems developer; we currently have a product that is almost 100% python based. It even runs a webserver in python and the performance is fine. It's a pretty complicated multi-threaded app.
I'm not the only one, either. Only a few months back I was investigating an embedded system, and tons of stuff in it was written in python.
Furthermore, my Symbian S60 smartphone runs python. It actually has some very impressive 3D apps written entirely in python
Python's speed is comparable to any other typical interpreted language.
That is one of the reasons why I find so many FSF supporters to be such hypocrits, they blather on about standards compliance, yet they use and abuse GCC extensions etc. The Linux kernel is horribly tainted in that way.
Linux can be compiled using the Intel C compiler
See include/linux/compiler*.h in your kernel source
Crusade: 1706, respelling of croisade (1570s), from M.Fr. croisade (16c.), Sp. cruzada, both from M.L. cruciata, pp. of cruciare "to mark with a cross," from L. crux (gen. crucis) "cross."
The crusades were Christian. Even the name says so. Don't pretend it wasn't.
Gulags were part of Stalinism. So was building dams, rocketry, idiotic agricultural policies, atheism and many other things. Stalin could have been a devout Catholic and still have had Gulags. What is hard to understand about this?