Just if you dont know, Most of Australia's power is from coal and we have no nuclear
Ironic as Australia is swimming in Uranium, with the largest reserves in the world.
Funny how we'd go from digging up one type of fossil fuel (coal - remenents of old biological matter) to another (uranium - remenents of exceedingly old supernovae).
I suspect that is vaguely deliberate...... If you ever saw the originals you'd probably understand why. If they over modernised it there would be a massive backlash. No seriously.. Death on the streets, arson, massive - widespread public unrest.....
A collapsing skyscraper is not going to be adequately modelled by dropping imaginarly steel balls of varying diameters.
Though it may seem unintuitive air resistance will have less impact than you think. It is not simply a case of something falling through the air. If you can ignore the (likely complex but subtle) mechanics of the structure the motion is most closely going to mirror that of free-fall in a vacuum.
To gain insight as to why, do the following experiment:
Get a thick heavy book, drop it from roughly head height - note the motion is dominated by gravity
Do the same with a sheet of paper - note the motion is dominated by air resistance
Now put the paper on top of the book and drop that - note that the motion of the paper is the same as the book. This is the same slipstream-like concept as a set of cyclists in "le Tour"
Now imagine doing the same - but with a concertina like structure - the top of the concertina will accelerate more rapidly than if the material below it didn't exist!
The idea of an "implosion" is laughable!
Since they also make no mention of their error estimates I think this can be clearly disregarded.
I assume it means time taken for a cycle of read/write/erasure. If it's based on Chalcogenide phase change materials (typically found in optical media) I suspect the timescale for writing and erasing will be ~10s of nS.
Can you outline examples of these conformance tests, or even better, are they freely available? I assume these are intended to make sure things that go on the wire have a sane value, fall between certain daily trading limits etc (to prevent things like the Mizuho cock-up) [*].
I suspect that the main culprit of "dodgy doubles" is likely to be people throwing together ad hoc codes behind the scenes, not the official interface to the exchanges.. (the "front" and "back" doors I mentioned earlier).
NatW^H^Hmeless huh? That gives me some confidence. Though it still doesn't make me happy with their online banking (the numbers don't add up). I still need to find someone that can make my balance - you know - balance..... Yes, I know, "retail" banking... Yuk!
I assume you know plenty of people that work deeper in the bowls of such organisations. Would you do an unofficial survey and find out how other people implement financial numerics? I'd wager you will be shocked!
[*] Tee hee, that story did make me smile. Poor guy I bet he felt terrible....
Believe me I was surprised and dismayed as well. I don't even work in banking and this is obvious to me.
The LSE feeds all use 18 digits for values, with the first 10 being implicitly before the decimal point and the remaining eight being after the implicit decimal point.
Fixed point arithmetic... fine. I'm sure the stuff that comes in the "front door" and goes out the "back door" is appropriately conforming. It has to be. What happens in between however seems to be up to the whim of the people in the bank.
No-one with the slightest clue about how to code would use floating point maths....
Perhaps you have hit the nail on the head...;-)
Are there any people in financial institutions that can comment (anonymously) on this? My information is limited to a handful of anecdotal evidence.
I suspect you will end up having to avoid most of them.
Friends of mine went off to work "In The City", when I quizzed them about their use of numbers for stock prices etc they were equally dismayed that things were being passed around as doubles. Often encoded as ASCII text in data streams as well, requiring different people to write their own ASCII->DOUBLE conversion depending on the representation of the stock tick. I think this kind of madness is quite prevelant.
As someone else pointed out, if you want to do things properly you can end up needing very big integers.
Perhaps the best option is to make sure people can only by and sell equities etc in numbers that can be exactly represented as doubles on a computer. It sounds crazy, but it's not as crazy as it looks. One of the reasons stocks etc are quoted as they are is probably due to the ease of the mental arithmetic.
Kudos to the parent of your post. At least he knows what he is having to do is dodgy and cares enough to check!
I don't know what the US laws are like, but over here in the UK if you find someone's lost property and keep it that's "stealing by finding". If the person is caught they can be prosecuted. I know this due to the "loss" of a laptop and an ensuing conversation with the boys in blue. Unfortunately it still hasn't phoned home, so I can't track the blighter....
As an addendum, I talked on the phone with a police officer explaining my desire to find the cuprit by tracing their IP etc and he understood, and was highly encouraging. Ah well...
It will be keeping somone elses lap hot now... (It was a PowerBook)...
We often read about managment problems with large software projects. The Apache web server is a large, well maintained and stable platform. This obviously didn't happen by accident but as a result of the team all knowing what they were supposed to do.
With this in mind, what are your personal top ten management do's and dont's with regard to large software projects?
Yeah, just imagine he'd seen a bunch of dangerous looking Mohawks or something. He might think it was some sort of hack attack..... [ducks]
[exit stage left]
Re:Works great with older setups & configs
on
Amanda 2.5 Released
·
· Score: 1
Ah, yes hence the "yet". That's why I called mine yarbu;-). It was really just a hack together to make sure I understood how rsync worked with hardlinks. I really wanted something that was very easy to configure, hence the RPM packages. Just install the rpm, do "man rpm" and off you go.
I'm quite pleased with it as having hourly backups has been a real life saver. The thing I always noted is that the stuff that's the most important is the most recent.... Frequent backups are good!
I'll probably update it in the near future to rewrite with Python. I think my desire to keep it as a shell script was misguided, really the server only works properly on Linux, though it will backup other clients just fine.
Ideally I'd like to couple it with inotify. That way backups can be done exceedingly quickly with inotify keeping track of what needs shifting. Also on the agenda is tolerance of server failure, when the server dies that means there is no backup protection! At the moment server replication is crude and wasteful.
If any one fancies joining in on this by all means let me know!
Re:Works great with older setups & configs
on
Amanda 2.5 Released
·
· Score: 1
As has been said many many times, history will repeat itself.
"History never repeats itself, but it does rhyme" - Mark Twain
Re, the disks. That's why I set up a script for backup called "yarbu", Yet Another Rsync Backup Utility. It's dirty but does its job remarkably well....
You mean like a Sun Sparc 5?
Those things seem nigh on indestructable. I remember opening one up once (the hard disk filled up) it was clogged solid with dust....
Slashdot Mirror
Ironic as Australia is swimming in Uranium, with the largest reserves in the world.
Funny how we'd go from digging up one type of fossil fuel (coal - remenents of old biological matter) to another (uranium - remenents of exceedingly old supernovae).
They really call it that? Wow! How.....
I suspect that is vaguely deliberate...... If you ever saw the originals you'd probably understand why. If they over modernised it there would be a massive backlash. No seriously.. Death on the streets, arson, massive - widespread public unrest.....
Sounds like a case for The Doctor....
So what are you saying....? Time to refactor? ;-)
At least they didn't try slapping on "terrorism" charges.
No, but I am intrigued. Do you have a link you can cite?
This is junk!
A collapsing skyscraper is not going to be adequately modelled by dropping imaginarly steel balls of varying diameters.
Though it may seem unintuitive air resistance will have less impact than you think. It is not simply a case of something falling through the air. If you can ignore the (likely complex but subtle) mechanics of the structure the motion is most closely going to mirror that of free-fall in a vacuum.
To gain insight as to why, do the following experiment:
The idea of an "implosion" is laughable!
Since they also make no mention of their error estimates I think this can be clearly disregarded.
I assume it means time taken for a cycle of read/write/erasure. If it's based on Chalcogenide phase change materials (typically found in optical media) I suspect the timescale for writing and erasing will be ~10s of nS.
Can you outline examples of these conformance tests, or even better, are they freely available? I assume these are intended to make sure things that go on the wire have a sane value, fall between certain daily trading limits etc (to prevent things like the Mizuho cock-up) [*].
I suspect that the main culprit of "dodgy doubles" is likely to be people throwing together ad hoc codes behind the scenes, not the official interface to the exchanges.. (the "front" and "back" doors I mentioned earlier).
NatW^H^Hmeless huh? That gives me some confidence. Though it still doesn't make me happy with their online banking (the numbers don't add up). I still need to find someone that can make my balance - you know - balance..... Yes, I know, "retail" banking... Yuk!
I assume you know plenty of people that work deeper in the bowls of such organisations. Would you do an unofficial survey and find out how other people implement financial numerics? I'd wager you will be shocked!
[*] Tee hee, that story did make me smile. Poor guy I bet he felt terrible....
The LSE feeds all use 18 digits for values, with the first 10 being implicitly before the decimal point and the remaining eight being after the implicit decimal point.
Fixed point arithmetic... fine. I'm sure the stuff that comes in the "front door" and goes out the "back door" is appropriately conforming. It has to be. What happens in between however seems to be up to the whim of the people in the bank.
No-one with the slightest clue about how to code would use floating point maths....
Perhaps you have hit the nail on the head... ;-)
Are there any people in financial institutions that can comment (anonymously) on this? My information is limited to a handful of anecdotal evidence.
The cynic in me would say that there was nothing wrong with their logic, just their arithmetic.
Friends of mine went off to work "In The City", when I quizzed them about their use of numbers for stock prices etc they were equally dismayed that things were being passed around as doubles. Often encoded as ASCII text in data streams as well, requiring different people to write their own ASCII->DOUBLE conversion depending on the representation of the stock tick. I think this kind of madness is quite prevelant.
As someone else pointed out, if you want to do things properly you can end up needing very big integers.
Perhaps the best option is to make sure people can only by and sell equities etc in numbers that can be exactly represented as doubles on a computer. It sounds crazy, but it's not as crazy as it looks. One of the reasons stocks etc are quoted as they are is probably due to the ease of the mental arithmetic.
Kudos to the parent of your post. At least he knows what he is having to do is dodgy and cares enough to check!
Tsk.... that was about five years ago..... *ahem*
As an addendum, I talked on the phone with a police officer explaining my desire to find the cuprit by tracing their IP etc and he understood, and was highly encouraging. Ah well...
It will be keeping somone elses lap hot now... (It was a PowerBook)...
Very good! Whoever you are. I wondered if anyone would get the link.
What enemy?
Obligatory PAL - "Picture Always Lousy".... Any others?
-ed
That's consultancy for you.
Never underestimate the amount of money to be made stating the obvious.
-ed
As I like to say:
"Be nice to people on the way up. You will meet them again on the way down."
We often read about managment problems with large software projects. The Apache web server is a large, well maintained and stable platform. This obviously didn't happen by accident but as a result of the team all knowing what they were supposed to do.
With this in mind, what are your personal top ten management do's and dont's with regard to large software projects?
Regards,
-ed
Yeah, just imagine he'd seen a bunch of dangerous looking Mohawks or something. He might think it was some sort of hack attack..... [ducks]
[exit stage left]
I'm quite pleased with it as having hourly backups has been a real life saver. The thing I always noted is that the stuff that's the most important is the most recent.... Frequent backups are good!
I'll probably update it in the near future to rewrite with Python. I think my desire to keep it as a shell script was misguided, really the server only works properly on Linux, though it will backup other clients just fine.
Ideally I'd like to couple it with inotify. That way backups can be done exceedingly quickly with inotify keeping track of what needs shifting. Also on the agenda is tolerance of server failure, when the server dies that means there is no backup protection! At the moment server replication is crude and wasteful.
If any one fancies joining in on this by all means let me know!
"History never repeats itself, but it does rhyme" - Mark Twain
Re, the disks. That's why I set up a script for backup called "yarbu", Yet Another Rsync Backup Utility. It's dirty but does its job remarkably well....
I really should get around to cleaning it up!
You mean like a Sun Sparc 5?
Those things seem nigh on indestructable. I remember opening one up once (the hard disk filled up) it was clogged solid with dust....