Download STK. It is free, although you might have to order it via mail, can't remember, not going to check. Buy the plugin (it isn't free). Enter the data for this rock (which is freely available on the net). Push 'go'. Read the trajectory from the results (it will give you a very pretty 3D picture. Now read up on the math that is used in the solver that you paid 20K dollars for. You will find the error bounds in there somewhere -- use them to calculate the rocks travel 'cone of probability'.
Good luck. I've got a degree in that stuff and I ain't touching it. Although honestly, showing that the rock gets *really* close? Hell, thats easy. Anyone that can write a few nested loops can get a half-assed estimate going in maybe a good weeks worth of coding. Someone who actually knows where to look (math-wise) could write the code in a day. I did something similar back when VB3 was brand new in less than 1000 lines of code.
I could write the code now in an hour or two.. but then I could also use that STK thing I mentioned. Hmmmm. I think I'll take their word for it.
M2 is nice (okay, it is awesome. I would kill for that wonderful search tool again), but god help you if you ever need/want to migrate:~(
Once you get a large (okay, huge) e-mail set M2 gets some funky errors.... Like disappearing e-mails for you and filters/searches breaking.
Don't get me wrong!!! I am using Opera right now --- Love it 99.5% of the time, it is a great prog. And I recommend it all the time. I just place a caveat the mail program.
I keep most of the e-mail I receive, with the exception of attachments. Those go in a seperate archive. Business thing. Most people would never run into a problem like this I imagine, although I've seen mention on the Opera msg boards.
A lot of factors come into play. Is it coming 'straight at us' (will it hit the atmosphere with the combined velocities of the orbiting earth and its own relative motion?). Or is it playing 'catch up' with the Earth, coming up behind us so that the relative velocity is lower?
Hell yeah, a solid nickle object that size could hit the surface given the right conditions! But with a shallow, grazing entry it would be unlikely to do so. And shallow entries are more likely.
However a fast, dead straight approach would give the asteroid/meteoroid only tenths of seconds of actual atmospheric contact. Earths orbital velocity around the sun is around 30km per second, and if the object were coming straight at us you can assume that its orbital velocity would be near to that; if it were falling toward the sun it would be higher, if ascending the velocity would be lower. So 60km/second would give the object about 1/2 a second in any 'real' atmosphere in a vertical descent profile. For some object which was solid and metallic there would be a nice new crater - not enough time for heat transfer to create the massive thermal gradients which would make the object shatter.
If the object were not completely solid the shockwaves created by its own passage through the atmosphere would likely cause it to explode into smaller peices, but even then you could expect a good number of those pieces to blast some pretty serious holes in things.
I once read, LONG ago in some book meant for 'tweens, that objects smaller than a VW bus tend to burn up. Objects larger stand a good chance getting significant chunks of themselves onto the surface of the planet.
mmm, you are right and wrong; caffeine does appear in some medications for migranes. It contracts blood vessels which can, in some cases, reduce the suffering of a migrain. However, for the most part drugs that include caffeine do so to speed the uptake of the actual pain relieving drug.
Referring to the drawings and particularly to FIG. 1, illustrating a terminal according to the present invention in block diagram form, keyboard 14 and a host computer are coupled to processor 16 which may comprise a type 8086 microprocessor manufactured by Intel Corporation. The processor 16 is connected to a processor bus to which a memory 18 is also connected. The microprocessor further includes a ROM (read only memory) in which firmware is stored. The host computer, or keyboard 14, sends original instructions, describing the displayed image, to processor 16, and these original instructions are stored in memory 18. In accordance with the present invention, the instructions stored may describe a 3D image utilizing vectors defined by X, Y and Z coordinates and directions.
Or if you use an LCD screen: A video display memory 24, which stores information in the form of a pixel bit map, receives the graphics data ultimately used for controlling the image on the CRT 28 during a raster scan.
Now wouldn't that be a bitch of an EULA:
By using this software you agree that you Computer System contains one or more of the following:
A level playing field, a little more understanding and less of the arrogance and favouritism currently in place will quickly change the perception of the US,
Dude, I don't know what the hell you've been smoking.. The United States has always* been for a level playing field!
*except where it was more beneficial to install a pro-US dictator, etc
Guessing, but I imagine the difference you are seeing is the fact that E=mc^2 isn't a 'real world' way to measure the conversion of mass to energy via matter-antimatter interaction.
Like anything else, there are inefficiencies which occure (e.g. energy is taken up by re-forming certain elements/compounds etc).
If I recall correctly the absolute most efficient energy conversion process is achieved by a black hole (ask me not the process by which this is done), with a conversion of mass to energy of something like 40% efficiency.
Matter-antimatter isn't anywhere near that.
Again, this is just a heads up:~) check the numbers at your leisure.
Re:Not outsourcing - from a business point of view
on
Inside Wal-Mart IT
·
· Score: 1
Uhm... incorporate.
The self employed pay LESS in taxes.... if they do it right.
We've found people buried under meters of ash too.
Personally, I fail to see how one can begin to claim to be able to tell the difference between a huge volcano erupting and a meteor which rips the core of the Earth open and ejects, oh yeah, everything that the volcano would.
The only difference is that meteors tend to contain larger concentrations of iridium and other fun elements. But if the asteriod didn't have that, could you ever tell the difference? I contend the answer is no.
So, if there is an iridium layer: Big ass whup'n. No layer? Then as you say... Who knows?
Or maybe the meteor landed on the top of a big ass volcano -- popped the cork;~)
A really cool light show. After the initial 'massive glowing crater' excitement, the really depressing stuff begins:
Depending on the angle of impact effects would range from 'basically nothing' to 'global winter'.
* Near side hit: Asteroid passes by the Earth *then* smacks into the moon
* Far side hit: Moon plays left tackle; catches asteroid before it goes by the Earth.
A 'near side' hit would probably throw enough ejecta into Earth orbit to have global concequences, possible ranging all the way up to the same effect as a nuclear winter. A guess would be that we would probably just see some seriously bad winters until the solar wind pushed all the atomized dust out of orbit -- no super-long term effects, but it would still be an Unhappy Event. Certainly a number of people would be killed by incoming ejecta, but no more so than generally die in car wrecks. Actually, more people would probably die in car wrecks because they were looking up at the fireballs streaking across the sky instead of driving.
A far side hit would *probably* just create a big-ass halo around the moon for a while. The key difference is the the ejecta would go up and OUT -- away from Earth orbit.
The impact crater would act kind of like a rocket nozzle, aiming gobs of rock and atmomized moon dust out into space -- or towards whatever is in its way. If it aims towards or obliqe to earth, much of that would go into orbit or enter earths atmosphere. Bad times. But the amount of stuff ejected depends on a whole slew of factors, things like 'did it hit bedrock or a 'valley' full of lunar dust?
While I am a rocket scientist (well, I have a degree anyway), I don't study impacts. These are just educated guesses based on err, my education;~)
Oh, and: No, a three mile asteroid could NOT significantly adjust the moons orbit and NO it would NOT end all tides, nor would it have any chance of seriously damaging the moon. Moon: 1738 km radius. asteroid: ~4.8km radius. We might need to re-calculate the moons orbit at the 5th decimal place after an impact.... Maybe.
Where 37 = 26 letters + 10 numbers + hyphen. Not case sensitive.
So, we saturate IPV6 at about 10 chars. Logically, 90% of those 10 char domains would be nonsense, which kinda makes the 63 char limit make sense for the length of a top-level domain (at least.info, what I found when searching for data).
Which is to say, you're right, there are certainly enough IP addresses! Sadly only one person gets 'biteme.com' for their VOIP number though....
I think it would make sense to consider a shift towards using email addresses for VOIP.
Anyway, I'm also probably the only guy here who thinks that we should have skipped 6 byte addressing and gone straight to 8. Do you think 47000 IP address per person will be enough in 50 years? I'll be marked flame bait for this, but I don't. Once the population reaches 10 billion, we are down to 28K IPs per person. Now lets start talking about networking street lights, cars, houses, pets, random plant life, etc etc etc...
The point is that we will always have NAT. It Just Makes Sense(tm). Why would you dump streets lights on the world network grid? etc etc I'm tired good night:~)
I think you pointed to the one and only reason a government agency would 'need to be' (read: 'find a way to make themselves') involved: Defense.
A private company would get some flak for firing a bunch of SAMs at any plane which came within 25NM. A government (or consortium of governments) would just issue a press release.
And your only line of defense is to shoot down ANYTHING that comes within about 25 miles of your ground station. Warn 'em from 100, and if they don't divert...
25 miles may seem a tad overkill, but there are missiles out there that travel at mach 5 or so. Pretty expensive defense systems are required to counter those;~)
considering that ATi is better at DirectX and nVidia
You have that backwords, right? Or does ATI just suck at both? I suppose it *was* a year or so ago, so the 'right now' modifier might come into play....
I certainly have never heard of anyone that had to return a laptop because NVidia couldn't write to specs: link.
After dealing with the issue for a month (favorite advice from laptop vendor: 'just disable hardware acceleration') I will most certainly never buy a laptop from said dealer, nor I will ever own another ATI card.
Dealer wasn't IBM (as per the link); it was Dell. What the hell is it about the crooked 'E' that makes a company turn to the dark side?
I'd prefer to see some requirements put in place that completely remove control of the jet from anyone on board and puts it in the hands of a security group on the ground as soon as there are any questionable issues on-board. Some manner in which the plane cannot be flown by terrorists as the control over the aircraft leaves as soon as its taken over.
Doesn't it just blow your mind how easy the solution could be to the whole 'airplanes as weapons' problem?
A big red button on the flight console. When the pilot pushes it the autopilot takes the plane to the nearest airport capable of taking said plane and lands. Period. End of discussion. No way to cancel the order, nadda.
The only issue, I believe, is weather; autopilot has issues with crosswind landings? Or won't attempt them over certain parameters? Not a commercial pilot, I wouldn't know.
Considering the ground control option.... it might be viable as a 'once the big red button is pushed option' (to handle those non-autopilot landings, lets say), but as a way to actually take control of an aircraft I would be a weee hesitant:~) And autopilot is SOOOO good, there is hardly any point in 'remote flying' except perhaps on that last mile.
The real problem is that there is no real interest in security.. only the illusion thereof, and then only enough to convince the general public that it's safe to fly.
As for air marshalls defending the cockpit... isn't that what first class is for?
The entire premise behind this "service" seems to be: fraud. I can think of no legitimate uses for it.
Ladies and gentlemen, a little background:
***All caller ID block does is add a 'do not show' flag to the ANI data****
It is up to the switch at the receiving end to strip that data when it sees said 'do not show' flag. THE DATA IS STILL THERE. How the hell else is the phone company going to bill for calls to 800 numbers? Collect the data from the dialing switch? HA! I'm not even sure that would be possible. Certainly not without a a hellofa lot of changes.
Spoofing is the only way to ensure you don't actually send your real call data (e.g. your phone number) down the line. I'm not positive, but I think you could seriously rape a company with an international 800 number too... just spoof your caller ID number to be some tiny ass third-world country and dial away.
For reference, I do software consulting for a phone company. Play with switch logs all to damned often.
Normally you rotate 3-vectors by multiplying them by an appropriate 3x3 matrix DOH! Sorry. I thought you were correcting me. I was confused by a/. response which simply expounded upon my previous post;~).
So, yes. A 3x3 describes your 'current' orientation in space, and a 1x3 matrix describes the angles of rotation about body axis. You must also assume *which* body axis to use. which is to say 'rotate about x, then z, then x again' by 20 deg, 30 deg and 15 deg, respectively. But this is so not the time for discussion of this long, *long* topic:~)
Especially when its moot, as I am pretty bloody sure that graphics cards do all or most rotations using quaternions. WAAAAAY less overhead, no divide by zeros.
A processor has specific pathways for specific operations. A very very very basic RISC processor may not even have a special path for a multiply op (over simplifying here, I don't think there is such a processor). So, by definition, a multiply operation would have to use the addition pathway, many many times.
Graphics processors have very very specialized ops -- operations which are hardware pathways. If you take a RISC processor and tell it to rotate a matrix of numbers, then you have to reduce the problem to simple commands (add, subtract, multiply, divide, binary shift etc) using other simple commands *in software*, then obtain the results of each operation and put them in context.
(what follows is a logical assumption, I don't code graphics) A typical GPU can rotate a 3x3 matrix using a hardware path: a method might be something like telling it the starting address of your 3x3 matrix, and that you want to rotate it by some sequence (euler angles are fun). The processor would handle the WHOLE TASK in hardware, and spit out your result, probably in the same memory addresses. So you have ONE operation to rotate the matrix. Not 200.
For way more detail, pretend you have no MULT op on some processor: Let us multiply 4*8 using some pretend asm language: push 8 A: ; put '8' into the A register push 8 B: ; put '8' into the B register ADD A,B,C: ; put the result of A + B into C push C, A: ; put C into A ADD A,B,C: ; 16 + 8 = 24, in C PUSH C, A: ; A = 24 ADD A,B,C: ; C is now 4*8
'C' is now 4*8 = 32. Obviously you would use a loop for more arbitrary cases etc.
Now let us do that with a MULT oparand: push 4 A: ; the A register has a value of 4 push 8 B: ; the B register has a value of 8 MULT A,B,C: ; multiply A*B and store it in C
C = 32. YOu are done. You used 3 operations instead of 7. It is left as an exercise to the reader to calculate the number of cycles this took.
Slashdot Mirror
Download STK. It is free, although you might have to order it via mail, can't remember, not going to check. Buy the plugin (it isn't free). Enter the data for this rock (which is freely available on the net). Push 'go'. Read the trajectory from the results (it will give you a very pretty 3D picture. Now read up on the math that is used in the solver that you paid 20K dollars for. You will find the error bounds in there somewhere -- use them to calculate the rocks travel 'cone of probability'.
Good luck. I've got a degree in that stuff and I ain't touching it. Although honestly, showing that the rock gets *really* close? Hell, thats easy. Anyone that can write a few nested loops can get a half-assed estimate going in maybe a good weeks worth of coding. Someone who actually knows where to look (math-wise) could write the code in a day. I did something similar back when VB3 was brand new in less than 1000 lines of code.
I could write the code now in an hour or two.. but then I could also use that STK thing I mentioned. Hmmmm. I think I'll take their word for it.
Cheers.
Dude. I....I mean hell man.
Damn. Who the hell hasn't heard of Orbital? Wtf? Pegasus? They've worked with Rutan??
beh.
M2 is nice (okay, it is awesome. I would kill for that wonderful search tool again), but god help you if you ever need/want to migrate :~(
Once you get a large (okay, huge) e-mail set M2 gets some funky errors.... Like disappearing e-mails for you and filters/searches breaking.
Don't get me wrong!!! I am using Opera right now --- Love it 99.5% of the time, it is a great prog. And I recommend it all the time. I just place a caveat the mail program.
I keep most of the e-mail I receive, with the exception of attachments. Those go in a seperate archive. Business thing. Most people would never run into a problem like this I imagine, although I've seen mention on the Opera msg boards.
A lot of factors come into play. Is it coming 'straight at us' (will it hit the atmosphere with the combined velocities of the orbiting earth and its own relative motion?). Or is it playing 'catch up' with the Earth, coming up behind us so that the relative velocity is lower?
Hell yeah, a solid nickle object that size could hit the surface given the right conditions! But with a shallow, grazing entry it would be unlikely to do so. And shallow entries are more likely.
However a fast, dead straight approach would give the asteroid/meteoroid only tenths of seconds of actual atmospheric contact. Earths orbital velocity around the sun is around 30km per second, and if the object were coming straight at us you can assume that its orbital velocity would be near to that; if it were falling toward the sun it would be higher, if ascending the velocity would be lower. So 60km/second would give the object about 1/2 a second in any 'real' atmosphere in a vertical descent profile. For some object which was solid and metallic there would be a nice new crater - not enough time for heat transfer to create the massive thermal gradients which would make the object shatter.
If the object were not completely solid the shockwaves created by its own passage through the atmosphere would likely cause it to explode into smaller peices, but even then you could expect a good number of those pieces to blast some pretty serious holes in things.
I once read, LONG ago in some book meant for 'tweens, that objects smaller than a VW bus tend to burn up. Objects larger stand a good chance getting significant chunks of themselves onto the surface of the planet.
mmm, you are right and wrong; caffeine does appear in some medications for migranes. It contracts blood vessels which can, in some cases, reduce the suffering of a migrain. However, for the most part drugs that include caffeine do so to speed the uptake of the actual pain relieving drug.
the less they see.
Dir sir or madam: You obviously have no grasp of satire.
Or if you use an LCD screen:
A video display memory 24, which stores information in the form of a pixel bit map, receives the graphics data ultimately used for controlling the image on the CRT 28 during a raster scan.
Now wouldn't that be a bitch of an EULA:
By using this software you agree that you Computer System contains one or more of the following:
An AMD Central Processing Unit
A Non-CRT Monitor ;~)
A level playing field, a little more understanding and less of the arrogance and favouritism currently in place will quickly change the perception of the US,
;~)
Dude, I don't know what the hell you've been smoking.. The United States has always* been for a level playing field!
*except where it was more beneficial to install a pro-US dictator, etc
Guessing, but I imagine the difference you are seeing is the fact that E=mc^2 isn't a 'real world' way to measure the conversion of mass to energy via matter-antimatter interaction.
:~) check the numbers at your leisure.
Like anything else, there are inefficiencies which occure (e.g. energy is taken up by re-forming certain elements/compounds etc).
If I recall correctly the absolute most efficient energy conversion process is achieved by a black hole (ask me not the process by which this is done), with a conversion of mass to energy of something like 40% efficiency.
Matter-antimatter isn't anywhere near that.
Again, this is just a heads up
Uhm... incorporate.
The self employed pay LESS in taxes.... if they do it right.
And it can be a LOT less.
Me == case and point.
ymmv.
'Better that a thousand innocent be punished than a single guilty go free'
Or something near that.
We've found people buried under meters of ash too.
;~)
Personally, I fail to see how one can begin to claim to be able to tell the difference between a huge volcano erupting and a meteor which rips the core of the Earth open and ejects, oh yeah, everything that the volcano would.
The only difference is that meteors tend to contain larger concentrations of iridium and other fun elements. But if the asteriod didn't have that, could you ever tell the difference? I contend the answer is no.
So, if there is an iridium layer: Big ass whup'n. No layer? Then as you say... Who knows?
Or maybe the meteor landed on the top of a big ass volcano -- popped the cork
Yup. I'll take the non-radioactive smoking hole in the ground any day.
And you forgot poodles.
A really cool light show. After the initial 'massive glowing crater' excitement, the really depressing stuff begins:
;~)
Depending on the angle of impact effects would range from 'basically nothing' to 'global winter'.
* Near side hit: Asteroid passes by the Earth *then* smacks into the moon
* Far side hit: Moon plays left tackle; catches asteroid before it goes by the Earth.
A 'near side' hit would probably throw enough ejecta into Earth orbit to have global concequences, possible ranging all the way up to the same effect as a nuclear winter. A guess would be that we would probably just see some seriously bad winters until the solar wind pushed all the atomized dust out of orbit -- no super-long term effects, but it would still be an Unhappy Event. Certainly a number of people would be killed by incoming ejecta, but no more so than generally die in car wrecks. Actually, more people would probably die in car wrecks because they were looking up at the fireballs streaking across the sky instead of driving.
A far side hit would *probably* just create a big-ass halo around the moon for a while. The key difference is the the ejecta would go up and OUT -- away from Earth orbit.
The impact crater would act kind of like a rocket nozzle, aiming gobs of rock and atmomized moon dust out into space -- or towards whatever is in its way. If it aims towards or obliqe to earth, much of that would go into orbit or enter earths atmosphere. Bad times. But the amount of stuff ejected depends on a whole slew of factors, things like 'did it hit bedrock or a 'valley' full of lunar dust?
While I am a rocket scientist (well, I have a degree anyway), I don't study impacts. These are just educated guesses based on err, my education
Oh, and: No, a three mile asteroid could NOT significantly adjust the moons orbit and NO it would NOT end all tides, nor would it have any chance of seriously damaging the moon. Moon: 1738 km radius. asteroid: ~4.8km radius. We might need to re-calculate the moons orbit at the 5th decimal place after an impact.... Maybe.
DOH! I said Plain Old Text! bah. Fine,
.LT. 256^6 .LT. 37^10
37^9
I remember FORTRAN better than HTML. deal.
37^9 256^6 37^10
.info, what I found when searching for data).
:~)
Where 37 = 26 letters + 10 numbers + hyphen. Not case sensitive.
So, we saturate IPV6 at about 10 chars. Logically, 90% of those 10 char domains would be nonsense, which kinda makes the 63 char limit make sense for the length of a top-level domain (at least
Which is to say, you're right, there are certainly enough IP addresses! Sadly only one person gets 'biteme.com' for their VOIP number though....
I think it would make sense to consider a shift towards using email addresses for VOIP.
Anyway, I'm also probably the only guy here who thinks that we should have skipped 6 byte addressing and gone straight to 8. Do you think 47000 IP address per person will be enough in 50 years? I'll be marked flame bait for this, but I don't. Once the population reaches 10 billion, we are down to 28K IPs per person. Now lets start talking about networking street lights, cars, houses, pets, random plant life, etc etc etc...
The point is that we will always have NAT. It Just Makes Sense(tm). Why would you dump streets lights on the world network grid? etc etc I'm tired good night
I think you pointed to the one and only reason a government agency would 'need to be' (read: 'find a way to make themselves') involved: Defense.
;~)
A private company would get some flak for firing a bunch of SAMs at any plane which came within 25NM. A government (or consortium of governments) would just issue a press release.
And your only line of defense is to shoot down ANYTHING that comes within about 25 miles of your ground station. Warn 'em from 100, and if they don't divert...
25 miles may seem a tad overkill, but there are missiles out there that travel at mach 5 or so. Pretty expensive defense systems are required to counter those
cheers,
considering that ATi is better at DirectX and nVidia
You have that backwords, right? Or does ATI just suck at both? I suppose it *was* a year or so ago, so the 'right now' modifier might come into play....
I certainly have never heard of anyone that had to return a laptop because NVidia couldn't write to specs: link.
After dealing with the issue for a month (favorite advice from laptop vendor: 'just disable hardware acceleration') I will most certainly never buy a laptop from said dealer, nor I will ever own another ATI card.
Dealer wasn't IBM (as per the link); it was Dell. What the hell is it about the crooked 'E' that makes a company turn to the dark side?
I'd prefer to see some requirements put in place that completely remove control of the jet from anyone on board and puts it in the hands of a security group on the ground as soon as there are any questionable issues on-board. Some manner in which the plane cannot be flown by terrorists as the control over the aircraft leaves as soon as its taken over.
:~) And autopilot is SOOOO good, there is hardly any point in 'remote flying' except perhaps on that last mile.
Doesn't it just blow your mind how easy the solution could be to the whole 'airplanes as weapons' problem?
A big red button on the flight console. When the pilot pushes it the autopilot takes the plane to the nearest airport capable of taking said plane and lands. Period. End of discussion. No way to cancel the order, nadda.
The only issue, I believe, is weather; autopilot has issues with crosswind landings? Or won't attempt them over certain parameters? Not a commercial pilot, I wouldn't know.
Considering the ground control option.... it might be viable as a 'once the big red button is pushed option' (to handle those non-autopilot landings, lets say), but as a way to actually take control of an aircraft I would be a weee hesitant
The real problem is that there is no real interest in security.. only the illusion thereof, and then only enough to convince the general public that it's safe to fly.
As for air marshalls defending the cockpit... isn't that what first class is for?
Why the fuck isn't the parent marked flame bait?
The entire premise behind this "service" seems to be: fraud. I can think of no legitimate uses for it.
Ladies and gentlemen, a little background:
***All caller ID block does is add a 'do not show' flag to the ANI data****
It is up to the switch at the receiving end to strip that data when it sees said 'do not show' flag. THE DATA IS STILL THERE. How the hell else is the phone company going to bill for calls to 800 numbers? Collect the data from the dialing switch? HA! I'm not even sure that would be possible. Certainly not without a a hellofa lot of changes.
Spoofing is the only way to ensure you don't actually send your real call data (e.g. your phone number) down the line. I'm not positive, but I think you could seriously rape a company with an international 800 number too... just spoof your caller ID number to be some tiny ass third-world country and dial away.
For reference, I do software consulting for a phone company. Play with switch logs all to damned often.
Normally you rotate 3-vectors by multiplying them by an appropriate 3x3 matrix /. response which simply expounded upon my previous post ;~).
:~)
DOH! Sorry. I thought you were correcting me. I was confused by a
So, yes. A 3x3 describes your 'current' orientation in space, and a 1x3 matrix describes the angles of rotation about body axis. You must also assume *which* body axis to use. which is to say 'rotate about x, then z, then x again' by 20 deg, 30 deg and 15 deg, respectively. But this is so not the time for discussion of this long, *long* topic
Especially when its moot, as I am pretty bloody sure that graphics cards do all or most rotations using quaternions. WAAAAAY less overhead, no divide by zeros.
Cheers,
yeeesss. Or use quaternions. Please though, lets not confuse the boy ;~).
*wham* question answered.
My bad!
A processor has specific pathways for specific operations. A very very very basic RISC processor may not even have a special path for a multiply op (over simplifying here, I don't think there is such a processor). So, by definition, a multiply operation would have to use the addition pathway, many many times.
Graphics processors have very very specialized ops -- operations which are hardware pathways. If you take a RISC processor and tell it to rotate a matrix of numbers, then you have to reduce the problem to simple commands (add, subtract, multiply, divide, binary shift etc) using other simple commands *in software*, then obtain the results of each operation and put them in context.
(what follows is a logical assumption, I don't code graphics)
A typical GPU can rotate a 3x3 matrix using a hardware path: a method might be something like telling it the starting address of your 3x3 matrix, and that you want to rotate it by some sequence (euler angles are fun). The processor would handle the WHOLE TASK in hardware, and spit out your result, probably in the same memory addresses. So you have ONE operation to rotate the matrix. Not 200.
For way more detail, pretend you have no MULT op on some processor: Let us multiply 4*8 using some pretend asm language:
push 8 A: ; put '8' into the A register
push 8 B: ; put '8' into the B register
ADD A,B,C: ; put the result of A + B into C
push C, A: ; put C into A
ADD A,B,C: ; 16 + 8 = 24, in C
PUSH C, A: ; A = 24
ADD A,B,C: ; C is now 4*8
'C' is now 4*8 = 32. Obviously you would use a loop for more arbitrary cases etc.
Now let us do that with a MULT oparand:
push 4 A: ; the A register has a value of 4
push 8 B: ; the B register has a value of 8
MULT A,B,C: ; multiply A*B and store it in C
C = 32. YOu are done. You used 3 operations instead of 7. It is left as an exercise to the reader to calculate the number of cycles this took.
Cheers, and good luck!