which is why a single pass of/dev/zero will wipe a recentish disk beyond recovery.
That doesn't sound right at all. The only difference between between wiping/dev/sdax and/dev/sda is which sector you start in. Starting in sector 0 (/dev/sda/) simply means overwriting the boot sector (usually MBR), which means you lose the primary partition table as well. Any partitioning software can trivially create that again.
You are right that disks don't simply write the bytes you send it onto the disk, but you cannot access or wipe the physical structures through any/dev/* trickery.
I checked again, and there are some mini-ITX boards that do have serial ports. Other than that, the only non-used motherboard I have found with a serial port is an Asrock Socket A board, which is quite ancient by today's standards.
At work, I have a PC that does not have an RS232 port, so I had to get a USB adapter. At home, under my desk, I have a computer just a few years old, also without RS232 (it does have parallel though).
Finally, looking through the motherboard selection at my local webshop, I see that RS232 is not just disappearing, it's gone. Not one board out of about 50 models of various sizes that I checked has it (I looked at the pictures of the connector side as well to make sure). The closest I can get is an old nForce3 board that takes DDR400 memory, on an auction site. That one has a serial port.
And to be honest - a lot of the hoi polloi DO need hype - in the same way that the majority of the population are content to be lead rather than think independently for themselves in terms of politics or even the way they live their lives (go to college, get a job, get married, raise a family, die - the great american dream).
NASA doesn't need Ares, they can just use your horse, jeez.
I was part of the initial pilot here in Finland for pre-filled tax forms many years ago, and by now I assume everyone gets them. My employer reports my income and withholds the relevant amount in taxes (a few other instances do some automatic reporting too). The consequence is that since I only have one source of taxable income, I don't fill out anything, and don't need send in anything either. I basically look through the form (one large sheet of folded paper), conclude nothing needs to be changed, and ignore it.
Obviously my financial affairs are simple enough, in particular since I don't have a business, but I'd assume that's the case for most people.
Needless to say, the market for personal tax software is not booming here.
Manufacturing a chip and distributing it in a device are two different uses of the technology. Besides, what if instead of charging the chip manufacturer $10, they charge $5 and then another $5 from the device manufacturer?
That's right, nobody here knows how much they charge, so no need to rant.
It has nothing to do with phones. The patents Nokia have are essential to the GSM standard, and are thus licensed for a reasonable price to members of the standards body, which Apple apparently don't want to be a member of. More here.
It's not just another way of interpreting a tab, it's the right way to interpret a tab: semantically, not as a character in itself. The point with elastic tabs is to use editors that support it, not to change the world of all the old bearded ones.
Realize that flipping 2 coins is the same thing as flipping one coin twice. The problem with your logic is that one of the coins has to be heads. If you flip coin X and find that it is tails, you can't claim that coin Y must be heads unless you flip it. This would mean that the results of one flip affect another, which is not true.
But there's the rub. I don't claim that coin flips would ever affect each other directly, but the phrasing of the question causes them to indirectly affect each other if they're both tails. Let's flip one coin and see what happens:
Coin 1: tails - no heads yet
Coin 2: heads - one heads, but the first one was tails
Coin 1: heads - Bingo!
Coin 2: tails - damn
Coin 1: heads
Coin 2: heads - both heads, success
Coin 1: tails - no heads yet
Coin 2: tails - no heads at all, so no trial
Therefore, you start with one coin heads and dont worry about its outcome (because it has to be heads). It cant change. It doesn't matter if you start with the first coin being heads or the second coin being heads, as long as one of them is predetermined to be heads, and you flip the other.
I agree.
The simplified problem is simply what are the probabilities associated with the flipped coin (that doesnt necessarily have to be heads)
Right. So there are two possibilities, either one is heads or the other. As a consequence, there are two possible ways that one coin is heads and the other is tails (as you've said). But there is only one possibility for both coins to be heads.
Now this all obviously assumes the coins to be distinct. If they're completely interchangeable, then it wouldn't make sense to talk about one or the other, and the probability collapses to 50%.
You are trying to claim that flipping the coin and getting heads or tails will change the color of the car coming down the street, when we already prefaced that we know what color it is.
It wouldn't change the car, but it would change the trial. Besides, that simplification's not quite the same. You'd have to say "if the car is red or the coin is heads", for it to be the same.
But we know one of the coins is heads, it says so in the question. The master of the game says that one coin is heads, and then that's the way it is. Otherwise it wouldn't be relevant to the question.
Also, you don't have to start with any coin at all. You simply ask yourself while looking at two covered coins: what is the probability that, if one is heads, the other is heads too. The question does not mention looking at any one coin first, and then deciding.
Regardless, how would you fix the code to match the question?
Consider what probability is asked for. The probability that is asked for is for the situation where two coins are flipped and one is heads. Original wording is thus: "If I flip two coins and one coin is heads...". One coin being heads is part of the assumption, a "default" as you put it, and we indeed don't know which one.
Furthermore this bit of Java, containing the copypaste from before, spits out roughly 0.33:
for (int i = 0; i < 10000; i++) { coin_X = random.nextInt(2); coin_Y = random.nextInt(2); if (coin_X == 0 && coin_Y == 0) continue;
flips++; if (coin_X == 1 && coin_Y == 1) success++;
Slashdot Mirror
which is why a single pass of /dev/zero will wipe a recentish disk beyond recovery.
That doesn't sound right at all. The only difference between between wiping /dev/sdax and /dev/sda is which sector you start in. Starting in sector 0 (/dev/sda/) simply means overwriting the boot sector (usually MBR), which means you lose the primary partition table as well. Any partitioning software can trivially create that again.
You are right that disks don't simply write the bytes you send it onto the disk, but you cannot access or wipe the physical structures through any /dev/* trickery.
There's no reason both can't be true.
I checked again, and there are some mini-ITX boards that do have serial ports. Other than that, the only non-used motherboard I have found with a serial port is an Asrock Socket A board, which is quite ancient by today's standards.
Active RAM means memory that is actively used, meaning reads and writes, which take energy. It's still less than fetching from disk though.
It's even better to zoom all the way out and discover that the problem is at least 5000 years old. Clearly no rush to find solutions.
Aren't most forklifts electric, especially ones that fit indoors, i.e. not container-hauling ones?
At work, I have a PC that does not have an RS232 port, so I had to get a USB adapter. At home, under my desk, I have a computer just a few years old, also without RS232 (it does have parallel though).
Finally, looking through the motherboard selection at my local webshop, I see that RS232 is not just disappearing, it's gone. Not one board out of about 50 models of various sizes that I checked has it (I looked at the pictures of the connector side as well to make sure). The closest I can get is an old nForce3 board that takes DDR400 memory, on an auction site. That one has a serial port.
Conclusion: the serial port went away years ago.
And to be honest - a lot of the hoi polloi DO need hype - in the same way that the majority of the population are content to be lead rather than think independently for themselves in terms of politics or even the way they live their lives (go to college, get a job, get married, raise a family, die - the great american dream).
NASA doesn't need Ares, they can just use your horse, jeez.
It's not the carrying around that's burdensome, it's getting the OTP data to wherever you're connecting.
Wall adapters - When you old walls don't fit your new Windows.
How much is that 10% worth?
And these "whiners" are helping by telling what that something else should be, for them to buy it. Market research for free.
That, and she hates Windows.
No more reason is needed.
Obviously my financial affairs are simple enough, in particular since I don't have a business, but I'd assume that's the case for most people.
Needless to say, the market for personal tax software is not booming here.
That's right, nobody here knows how much they charge, so no need to rant.
It has nothing to do with phones. The patents Nokia have are essential to the GSM standard, and are thus licensed for a reasonable price to members of the standards body, which Apple apparently don't want to be a member of. More here.
I wish I could type this message that I'm typing right now in a proportional font.
You could try loading a custom CSS for slashdot with
input { font-family: xyz; }
It's not just another way of interpreting a tab, it's the right way to interpret a tab: semantically, not as a character in itself. The point with elastic tabs is to use editors that support it, not to change the world of all the old bearded ones.
I think Google was the default for many people before it was made a default in browsers.
Does that mean the Microsoft icon changes to a Borg Ballmer?
Dear god no. Borg Bill looks funny, Borg Ballmer would scare away children and adults alike.
There's a similar series with the same doctor performing the autopsies called Anatomy for Beginners. Very uncensored and informative.
Realize that flipping 2 coins is the same thing as flipping one coin twice. The problem with your logic is that one of the coins has to be heads. If you flip coin X and find that it is tails, you can't claim that coin Y must be heads unless you flip it. This would mean that the results of one flip affect another, which is not true.
But there's the rub. I don't claim that coin flips would ever affect each other directly, but the phrasing of the question causes them to indirectly affect each other if they're both tails. Let's flip one coin and see what happens:
Therefore, you start with one coin heads and dont worry about its outcome (because it has to be heads). It cant change. It doesn't matter if you start with the first coin being heads or the second coin being heads, as long as one of them is predetermined to be heads, and you flip the other.
I agree.
The simplified problem is simply what are the probabilities associated with the flipped coin (that doesnt necessarily have to be heads)
Right. So there are two possibilities, either one is heads or the other. As a consequence, there are two possible ways that one coin is heads and the other is tails (as you've said). But there is only one possibility for both coins to be heads.
Now this all obviously assumes the coins to be distinct. If they're completely interchangeable, then it wouldn't make sense to talk about one or the other, and the probability collapses to 50%.
You are trying to claim that flipping the coin and getting heads or tails will change the color of the car coming down the street, when we already prefaced that we know what color it is.
It wouldn't change the car, but it would change the trial. Besides, that simplification's not quite the same. You'd have to say "if the car is red or the coin is heads", for it to be the same.
If you find that coin X is tails
But we know one of the coins is heads, it says so in the question. The master of the game says that one coin is heads, and then that's the way it is. Otherwise it wouldn't be relevant to the question.
Also, you don't have to start with any coin at all. You simply ask yourself while looking at two covered coins: what is the probability that, if one is heads, the other is heads too. The question does not mention looking at any one coin first, and then deciding.
Regardless, how would you fix the code to match the question?
Furthermore this bit of Java, containing the copypaste from before, spits out roughly 0.33 :
Feel free to run it.
When calculating probabilities, language and specification is always an issue.