Pi is a transcendental, infinitely non-recurring number: every finite sequence of numbers is present within it, including all "truly random sequences", of any length. Although, of course, some of them start at a very large offset indeed.
The open format would be `plain text', which you enter into the address bar of your browser or commit to memory for later. The sheer inconvenience of having to use a cuecat, rather than type eg. pepsi.com, was one of the highlighted factors in its failure, as I recall.
Water boils at 100 deg C at one atmosphere only. It will boil at about 60 deg C at the top of tall mountains - you can't make good coffee on Everest - and can be boiled at increasing pressures up to its critical point (380 deg C at 218 atm) after which it exists as a superfluid, showing both liquid and gas character.
High temperature is normal for good coffee: preparation of good espresso will use superheated steam to extract the most flavour from the beans, for instance. Not that I'm suggesting McDonald's prepare good coffee.
Rendering a world in 3d requires you to do *a lot* of very simple maths. OpenGL breaks down the operations into two steps, DirectX is essentially the same.
"Per vertex": the 3d world is made out of triangles. The camera position and viewpoint is expressed as a matrix, and subject to a matrix inversion, a simple mathematical transform. Every corner of every triangle (vertex) is expressed as a matrix, and then multiplied by the inverted camera matrix. The product is the (x,y) position on your screen, together with the depth (distance).
Matrix maths is easy, it's a series of multiplications followed by a series of sums. A general purpose CPU has to follow the instructions for each vertex every time, which is time consuming. A specialised GPU has circuitry which does this maths, and only this, and thus can run many at once at considerable speed.
"Per fragment": if you were rendering to the screen, you could think of this as per-pixel, but you could rerender each pixel many times to anti-alias, or you could render to a file, or do 3d tricks like Valve's Portal by rendering alternative views elsewhere, first.
Once you've converted your triangles into what they look like on the screen, you need to colour them in. Old-school 3d graphics (late 80's) might use a single colour for each one, but we've come to expect more. Texture rendering is easy maths: load the texture from memory, interpolate how far along the texture the part of the triangle you want is, and put that colour of the texture on the fragment you're rendering. General purpose CPUs can do this, but rendering the entire world takes a lot of time. As a bonus, each "fragment" is a seperate bit of maths, so lots of "pixel shaders" (specialised GPU circuits) can work on fragments separately, and pool their results for speed.
GPUs have really, really, fast local memory compared to CPUs. It's optimised for reading, not writing, as textures don't need to be changed that often. General purpose CPUs need to check whether multiple cores are using the same memory, as they are quite likely to write and change it in general operation, slowing things down. Also, GPUs have specialised circuits for texture maths, and only this maths, which lets them do it faster.
In addition, some other fragment tricks (eg. if you add a bit of grey with increasing distance, you get a "fog" effect; if you add some white depending on the angle of the triangle, it looks shiny and reflective) can have specialised bits of circuitry on the GPU. Not hard maths, but you can do it faster if that's all you can do.
GPUs now also tend to have provision for managing your triangle lists and whatnot which lets them crank out the maths faster than if they had to wait on the CPU.
Be careful of the way you read OSX's activity monitor pages. The cocoa frameworks are lazy by design: for instance, if you inform it to load an image, it will mark it as being in 'virtual memory', but not actually touch the disk until you try to draw it to screen, when the memory manager then does the lifting. Opening ten thousand images in a program doesn't take a second, but drawing them to screen will cause disk thrashing.
Makes sense, because what's the point of starting to load them all, running out of RAM, and then writing them to the pagefile on the disk, and then reading them again when you need them.
Consequentially, on startup most of/System and/Library end up in 'virtual memory'. On Activity Monitor on my Mac, up 19d, has a 'VM size' of 34.6 Gb. More important is the page in / outs, which stand at a little over 1.00 Mb for me. If I was short on RAM, that would be a lot, lot more.
I do love this programme, it ties together all the nonsense that I have / am forced to use so that I know what I'm doing...
* my own iBook, running iCal
* iPod sync'ed off of iCal
* Novell Groupwise at work, on both company Dell laptop and desktop
* Windows Mobile 2003 PIM thing as my work mobile phone
And what runs on everything? The open source stuff, running on many platforms and generating files to import for everything. No agenda as to 'doesn't import / export files for other platforms'. Cracking interface too, simplicity itself. Perfection is when there's nothing extraneous left to remove.
To get to that speed, yes. I'd probably want to stop once I get there, too. It would suck to finally arrive after ten years in space and watch intelligent life sail by at ten miles per second.
Fair play to you sir, and those are some lucid and intelligent points you made. A shame they weren't more widely reported.
Was quite disappointed that none of the reports I saw showed the working for the number questions. I'd have expected no marks and to be failed on the test for just putting down the correct number, but I think there's a sorry disconnect between people who appreciate maths and people who report in the media.
Running on an ancient iBook G4 here, but just out of interest, certain things I've noticed that have really improved the battery life:
1. Swapping out the hard disk. The old one broke. The cheapest new one I could find in the shop was rated at half the number of amps (0.7A v. 1.4A)
2. Had one of the Sony batteries that got recalled. The new one was enormously better for battery life.
3. Continous upgrading of OS X over the five years I've had it.
4. Switch speed step to "always lowest" when it's on battery power, using the preferences. It's not like I'm going to be encoding DVDs when it's on the battery, and it stops the laptop getting quite so hot in my lap.
5. Turn the display down to minimum brightness. That thing uses about half the battery power, according to the system information tool.
Am now disappointed if I can't get five hours from the battery. Often more, if I'm just on the web or using vim/LaTeX.
I was suffering from the "fan of death", where the screen just went black occasionally, and then on trying to restart, the fan just blew and blew. Seems to be pretty similar to what everyone else is describing here too.
I used a bit of electrician's tabe scrunched up, but practically anything insulating should work:-)
4-year old iBook, has been running for a year with this fix, all good.
Lucid and intelligent; if only they'd listen.
Besides which, Professor Knuth? I $\heartsuit$ his work, use it for all my technical reporting at the office.
I was suffering from the "fan of death", where the screen just went black occasionally, and then on trying to restart, the fan just blew and blew. Seems to be pretty similar to what everyone else is describing here too.
I used a bit of electrician's tabe scrunched up, but practically anything insulating should work:-)
4-year old iBook, has been running for a year with this fix, all good.
Hex codes? Luxury! You'd have to write an interpreter if you wanted to enter hex codes. Decimal was what you entered speccy assembler in.
Correct ettiquete was to write out the assembly by hand, translate that to decimal by hand, and enter using some craptastic basic programme, like so:
10 LET A= "start pos"
20 LET B= "length"
30 "free a,b" : REM I FORGET THE CORRECT COMMAND
40 FOR C = A TO A+B
50 READ D
60 POKE C,D
70 NEXT C
80 SAVE "MYCODE" CODE A,B
90 DATA 201,... : REM MY HAND-TRANSLATED ASSEMBLER
And we thought we were lucky! Managed to write myself an abominable space invaders knock-off, back in the day.
Sounds convincing; however, certain classes of virus and worm fall outside this view. SQL Slammer? Didn't write to disk, didn't need to. Restarting your computer cleared the virus, for the few seconds it took to get infected again. A `read only' solution wouldn't help.
Properly set up and administered? You mean, not connected to a network? My exploit for a toaster would be to pop some bread in, hold down the tray lever until it caught fire, and the watch as it destroyed your house. It's lack of accessability that causes the security there, not the innate design perfection of a toaster.
I am also afraid that computers *are* appliances, and more, they're appliances that people require in order to do work. Halting the business world for a few months in order to `qualify' everyone would be more trouble than the internet's compromised machines are worth.
For what my tuppence is worth:
1. Security by design: computers shouldn't need virus checkers. Probably also strength in diversity: if less people ran windows, less people could spread windows viruses.
2. Target the cause of the problem. If goods/services couldn't be sold by spam email, then there would be no incentive to send them.
3. User education, with a more inclusive and less elitist stance from the internet experts.
4. Quenching at source: ISPs should have a procedure for stopping spam zombies. Perhaps blocking port 25 at account creation, unless requested open by the user. Some method of blocking open relays too.
When I first got the click o' death, I sent back my iPod (3G, 40gb), since it was still under warranty, o' course. And the second one, when it was CoD too. Thrid one, didn't start to get the click of death until a year had passed, so was no longer warrantied.
Seemed to get it worse when the battery was a bit low; it didn't seem to have the juice to spin up the disk, but you couldn't charge it, because the click... click... click... seemed to be using up the charge faster than the power lead could feed it.
Since I had nothing to lose, I popped the case open and unhooked the drive. Could then charge the battery up to full; got the 'unhappy mac' on the display. Rehooked up the drive, and off it went. Have only had the CoD since then when the battery's been allowed to run down; possibly buying a new battery would be a good plan, but that's my beer money.
Wouldn't let an iPod anywhere near a commercial flight recorder however. My iPod suicided last week updating the music database from iTunes; all the music's still on it but it can't see it anymore; am going to have to spend some time copying it off, then letting iTunes copy it back on. Would hate a similar write-error to lose all my records of where I'd been flying.
So in the event of another worm causing a DDoS, like say, SQL Slammer (author has never been identified), which reached it's peak of infections in about quarter of an hour (75 000 hosts, fairly evenly distributed worldwide), what exactly would you bomb? Would you even have time?
The fix must surely be, to run only essential services by default, to patch as soon as possible once vulnerabilities are found, running varied implementations of standards-compliant software, user education, and strangulation of malware authors with a garrotte.
At $0.79 for a four minute track, I make that 81 continous days worth of music. When did they have time to earn the money to buy that lot, if they've been listening to it?
My (40gb) iPod full of CD-rips would run continously for about a month; I have nothing like time to listen to all of it, let alone all of it well.
Much as the thief series (1&2) represents some of my favourite games of all time, xbox deadly shadows does require some of the most convoluted gripping outside of halo. Duck and peer round a corner while drawing back a water arrow? Feel the pain.
I'd probably want something N64-based for the old non-crippling grip. Mind you, I was younger when I put in ten hours a day on Mario Kart 64:-(
Anyone know how the GetFileVersionInfo() call works? Does it just read the IBX file version as a sequence of unencryted bits from the.key file? If so, why not just take a hex editor to it and 'update' your old version to one which fill pass the DRM checks?
They have produced some good-looking graphs; however, the number of viruses observed (about 2 per year for the last decade) means that the substantial upturn could be little more than statistical noise.
I think it speaks for itself that, according to that PDF, the macintoshes with 1/50th of the market share have 1/1315th of the number of identified viruses, somewhat disproportionate to their decreased market share.
Have got MacAffee antivirus installed as corporate policy on my business peesee, and it humbles what is otherwise a fairly able laptop. Perhaps Apple's move to a more powerful architecture means that they can now shoulder the MacAffee burden too?
Slashdot Mirror
Looks like doom, but with a better story than half life?
Somewhere in the heavens, they are waiting...
Pi is a transcendental, infinitely non-recurring number: every finite sequence of numbers is present within it, including all "truly random sequences", of any length. Although, of course, some of them start at a very large offset indeed.
Alas, I'm too old for a fields medal.
The open format would be `plain text', which you enter into the address bar of your browser or commit to memory for later. The sheer inconvenience of having to use a cuecat, rather than type eg. pepsi.com, was one of the highlighted factors in its failure, as I recall.
Water boils at 100 deg C at one atmosphere only. It will boil at about 60 deg C at the top of tall mountains - you can't make good coffee on Everest - and can be boiled at increasing pressures up to its critical point (380 deg C at 218 atm) after which it exists as a superfluid, showing both liquid and gas character. High temperature is normal for good coffee: preparation of good espresso will use superheated steam to extract the most flavour from the beans, for instance. Not that I'm suggesting McDonald's prepare good coffee.
Rendering a world in 3d requires you to do *a lot* of very simple maths. OpenGL breaks down the operations into two steps, DirectX is essentially the same.
"Per vertex": the 3d world is made out of triangles. The camera position and viewpoint is expressed as a matrix, and subject to a matrix inversion, a simple mathematical transform. Every corner of every triangle (vertex) is expressed as a matrix, and then multiplied by the inverted camera matrix. The product is the (x,y) position on your screen, together with the depth (distance).
Matrix maths is easy, it's a series of multiplications followed by a series of sums. A general purpose CPU has to follow the instructions for each vertex every time, which is time consuming. A specialised GPU has circuitry which does this maths, and only this, and thus can run many at once at considerable speed.
"Per fragment": if you were rendering to the screen, you could think of this as per-pixel, but you could rerender each pixel many times to anti-alias, or you could render to a file, or do 3d tricks like Valve's Portal by rendering alternative views elsewhere, first.
Once you've converted your triangles into what they look like on the screen, you need to colour them in. Old-school 3d graphics (late 80's) might use a single colour for each one, but we've come to expect more. Texture rendering is easy maths: load the texture from memory, interpolate how far along the texture the part of the triangle you want is, and put that colour of the texture on the fragment you're rendering. General purpose CPUs can do this, but rendering the entire world takes a lot of time. As a bonus, each "fragment" is a seperate bit of maths, so lots of "pixel shaders" (specialised GPU circuits) can work on fragments separately, and pool their results for speed.
GPUs have really, really, fast local memory compared to CPUs. It's optimised for reading, not writing, as textures don't need to be changed that often. General purpose CPUs need to check whether multiple cores are using the same memory, as they are quite likely to write and change it in general operation, slowing things down. Also, GPUs have specialised circuits for texture maths, and only this maths, which lets them do it faster.
In addition, some other fragment tricks (eg. if you add a bit of grey with increasing distance, you get a "fog" effect; if you add some white depending on the angle of the triangle, it looks shiny and reflective) can have specialised bits of circuitry on the GPU. Not hard maths, but you can do it faster if that's all you can do.
GPUs now also tend to have provision for managing your triangle lists and whatnot which lets them crank out the maths faster than if they had to wait on the CPU.
That clear things up?
Be careful of the way you read OSX's activity monitor pages. The cocoa frameworks are lazy by design: for instance, if you inform it to load an image, it will mark it as being in 'virtual memory', but not actually touch the disk until you try to draw it to screen, when the memory manager then does the lifting. Opening ten thousand images in a program doesn't take a second, but drawing them to screen will cause disk thrashing.
/System and /Library end up in 'virtual memory'. On Activity Monitor on my Mac, up 19d, has a 'VM size' of 34.6 Gb. More important is the page in / outs, which stand at a little over 1.00 Mb for me. If I was short on RAM, that would be a lot, lot more.
Makes sense, because what's the point of starting to load them all, running out of RAM, and then writing them to the pagefile on the disk, and then reading them again when you need them.
Consequentially, on startup most of
I do love this programme, it ties together all the nonsense that I have / am forced to use so that I know what I'm doing...
* my own iBook, running iCal
* iPod sync'ed off of iCal
* Novell Groupwise at work, on both company Dell laptop and desktop
* Windows Mobile 2003 PIM thing as my work mobile phone
And what runs on everything? The open source stuff, running on many platforms and generating files to import for everything. No agenda as to 'doesn't import / export files for other platforms'. Cracking interface too, simplicity itself. Perfection is when there's nothing extraneous left to remove.
Keep up the good work!
I've got that, but it only seems to work half the time. Still, it's more reliable than my ISP.
To get to that speed, yes. I'd probably want to stop once I get there, too. It would suck to finally arrive after ten years in space and watch intelligent life sail by at ten miles per second.
Fair play to you sir, and those are some lucid and intelligent points you made. A shame they weren't more widely reported.
Was quite disappointed that none of the reports I saw showed the working for the number questions. I'd have expected no marks and to be failed on the test for just putting down the correct number, but I think there's a sorry disconnect between people who appreciate maths and people who report in the media.
Running on an ancient iBook G4 here, but just out of interest, certain things I've noticed that have really improved the battery life:
1. Swapping out the hard disk. The old one broke. The cheapest new one I could find in the shop was rated at half the number of amps (0.7A v. 1.4A)
2. Had one of the Sony batteries that got recalled. The new one was enormously better for battery life.
3. Continous upgrading of OS X over the five years I've had it.
4. Switch speed step to "always lowest" when it's on battery power, using the preferences. It's not like I'm going to be encoding DVDs when it's on the battery, and it stops the laptop getting quite so hot in my lap.
5. Turn the display down to minimum brightness. That thing uses about half the battery power, according to the system information tool.
Am now disappointed if I can't get five hours from the battery. Often more, if I'm just on the web or using vim/LaTeX.
My 2c.
What worked for me was the advice on the following page, which shows the offending chip:
:-)
http://coreyarnold.org/ibook/
I was suffering from the "fan of death", where the screen just went black occasionally, and then on trying to restart, the fan just blew and blew. Seems to be pretty similar to what everyone else is describing here too.
I used a bit of electrician's tabe scrunched up, but practically anything insulating should work
4-year old iBook, has been running for a year with this fix, all good.
Lucid and intelligent; if only they'd listen.
Besides which, Professor Knuth? I $\heartsuit$ his work, use it for all my technical reporting at the office.
Lucid and intelligent; if only they'd listen. Besides which, Professor Knuth? I $\heartsuit$ his work, use it for all my technical reporting at the office.
What worked for me was the advice on the following page:
:-)
http://coreyarnold.org/ibook/
I was suffering from the "fan of death", where the screen just went black occasionally, and then on trying to restart, the fan just blew and blew. Seems to be pretty similar to what everyone else is describing here too.
I used a bit of electrician's tabe scrunched up, but practically anything insulating should work
4-year old iBook, has been running for a year with this fix, all good.
Hex codes? Luxury! You'd have to write an interpreter if you wanted to enter hex codes. Decimal was what you entered speccy assembler in.
... : REM MY HAND-TRANSLATED ASSEMBLER
Correct ettiquete was to write out the assembly by hand, translate that to decimal by hand, and enter using some craptastic basic programme, like so:
10 LET A= "start pos"
20 LET B= "length"
30 "free a,b" : REM I FORGET THE CORRECT COMMAND
40 FOR C = A TO A+B
50 READ D
60 POKE C,D
70 NEXT C
80 SAVE "MYCODE" CODE A,B
90 DATA 201,
And we thought we were lucky! Managed to write myself an abominable space invaders knock-off, back in the day.
Sounds convincing; however, certain classes of virus and worm fall outside this view. SQL Slammer? Didn't write to disk, didn't need to. Restarting your computer cleared the virus, for the few seconds it took to get infected again. A `read only' solution wouldn't help. Properly set up and administered? You mean, not connected to a network? My exploit for a toaster would be to pop some bread in, hold down the tray lever until it caught fire, and the watch as it destroyed your house. It's lack of accessability that causes the security there, not the innate design perfection of a toaster. I am also afraid that computers *are* appliances, and more, they're appliances that people require in order to do work. Halting the business world for a few months in order to `qualify' everyone would be more trouble than the internet's compromised machines are worth. For what my tuppence is worth: 1. Security by design: computers shouldn't need virus checkers. Probably also strength in diversity: if less people ran windows, less people could spread windows viruses. 2. Target the cause of the problem. If goods/services couldn't be sold by spam email, then there would be no incentive to send them. 3. User education, with a more inclusive and less elitist stance from the internet experts. 4. Quenching at source: ISPs should have a procedure for stopping spam zombies. Perhaps blocking port 25 at account creation, unless requested open by the user. Some method of blocking open relays too.
Just to go off topic a little...
When I first got the click o' death, I sent back my iPod (3G, 40gb), since it was still under warranty, o' course. And the second one, when it was CoD too. Thrid one, didn't start to get the click of death until a year had passed, so was no longer warrantied.
Seemed to get it worse when the battery was a bit low; it didn't seem to have the juice to spin up the disk, but you couldn't charge it, because the click... click... click... seemed to be using up the charge faster than the power lead could feed it.
Since I had nothing to lose, I popped the case open and unhooked the drive. Could then charge the battery up to full; got the 'unhappy mac' on the display. Rehooked up the drive, and off it went. Have only had the CoD since then when the battery's been allowed to run down; possibly buying a new battery would be a good plan, but that's my beer money.
Wouldn't let an iPod anywhere near a commercial flight recorder however. My iPod suicided last week updating the music database from iTunes; all the music's still on it but it can't see it anymore; am going to have to spend some time copying it off, then letting iTunes copy it back on. Would hate a similar write-error to lose all my records of where I'd been flying.
So in the event of another worm causing a DDoS, like say, SQL Slammer (author has never been identified), which reached it's peak of infections in about quarter of an hour (75 000 hosts, fairly evenly distributed worldwide), what exactly would you bomb? Would you even have time? The fix must surely be, to run only essential services by default, to patch as soon as possible once vulnerabilities are found, running varied implementations of standards-compliant software, user education, and strangulation of malware authors with a garrotte.
At $0.79 for a four minute track, I make that 81 continous days worth of music. When did they have time to earn the money to buy that lot, if they've been listening to it?
My (40gb) iPod full of CD-rips would run continously for about a month; I have nothing like time to listen to all of it, let alone all of it well.
Yes, I though that on first read as well.
Silly string goes to war against IUDs http://en.wikipedia.org/wiki/IUD ???
"What are those girls doing with it?"
Much as the thief series (1&2) represents some of my favourite games of all time, xbox deadly shadows does require some of the most convoluted gripping outside of halo. Duck and peer round a corner while drawing back a water arrow? Feel the pain. I'd probably want something N64-based for the old non-crippling grip. Mind you, I was younger when I put in ten hours a day on Mario Kart 64 :-(
That's because you're typing with both hands.
Anyone know how the GetFileVersionInfo() call works? Does it just read the IBX file version as a sequence of unencryted bits from the .key file? If so, why not just take a hex editor to it and 'update' your old version to one which fill pass the DRM checks?
They have produced some good-looking graphs; however, the number of viruses observed (about 2 per year for the last decade) means that the substantial upturn could be little more than statistical noise.
I think it speaks for itself that, according to that PDF, the macintoshes with 1/50th of the market share have 1/1315th of the number of identified viruses, somewhat disproportionate to their decreased market share.
Have got MacAffee antivirus installed as corporate policy on my business peesee, and it humbles what is otherwise a fairly able laptop. Perhaps Apple's move to a more powerful architecture means that they can now shoulder the MacAffee burden too?