Razacaz' Conjoiner node

Program Update

2006-04-23T16:06:00.000Z

I expect anyone reading this is getting tired of me talking about my program all the time, but it's nearly finished now. And it can do 4 planets now. And colours. And Is accurate. And stuff.
I should probably mention that to do the graphics, I'm using a program called GrWin, which has a website here: http://spdg1.sci.shizuoka.ac.jp/grwinlib/english/. It's very, very useful for vector graphics, and I'd have been lost without it. Also, it's free. Kudos to the programmers who wrote it.
What I've done since I posted last night is move almost everything in function main into other functions. That separated the data from the process, and allowed me to add the other planets without having to rewrite everything. What I mean is that the procses was then generalised, and would accept any data fed into it, not just Earth[X_POS], or whatever.
That's another thing I changed. Instead of having separate variables for x and y coordinates etc, I created 1 array per planet to contain everything. That meant I only needed one parameter for my functions, not 5 or 6.
The last thing I did was the coloured trails. Previously, I had only a single colour. However, this had the disadvantage that once the planet had orbited once, you couldn't tell where it was. So I had to expand the arrays to store the last 2 positions, and then draw over them with the new colour.

YES!

2006-04-22T19:44:00.000Z

I did it! It's working! I have a planet that goes round the sun in a circular orbit once a year! Hah!
Also, I may be hyper.
Yes!

Status report

2006-03-16T18:44:00.000Z

Some more code for you to look at:

/* Gravity simulator version 3.0 by Alex Heywood*/
/* Actual units km, kg, N, days, */
#include
#include
#include
#include
#define GRAVITY 6.67e-11
#define PMASS 5.97e22
#define SUNMASS 2e22
main()
{
int days, secs;
double pX, pY, vX, vY, fX, fY, f, n;
/* Set starting Conditions */
pX = 0;
pY = 15e10;
vX = 8.9e11;
vY = 0;
days = 365;
/* Main Process */
while ( days > 0 )
{
secs = 86400;
while ( secs > 0 && (pX * pX) + (pY * pY) != 0) /* Second half of this statement prevent division by 0 */
{
f = (GRAVITY * SUNMASS * PMASS)/((pX * pX) + (pY * pY)); if (pX == 0) /* If either co-ordinate is 0, all the force will be along the othre axis. */
{ /* These if statements allow this, and prevent division of/by 0 */
fX = 0; fY = f;
}
else if (pY == 0)
{
fX = f; fY = 0;
}
else
{
n = (pX * pX) / (pY * pY);
fX = sqrt (n * f * f / (n + 1));
fY = sqrt (f * f / (n + 1));
}
if (pX > 0)
{
vX = vX - (fX / PMASS);
}
else
{
vX = vX + (fX / PMASS);
}
if (pY > 0)
{
vY = vY - (fY / PMASS);
}
else
{
vY = vY + (fY / PMASS);
}
pX = pX + vX; /* Definitely looking dodgy. What about halves? */
pY = pY + vY;
--secs;
}
--days;
printf ("x = %.2f, y = %.2f, days left = %4d \n", pX, pY, days);
}
printf ("End\n");
}
I should mention that it doesn't work properly yet. I messed around with the numbers to get it to work at all, and there's an error in it somewhere causing some strange behaviour. Still, the maths part is pretty much all there. Which leaves the graphics...
If anyone reading this has some experience writing in C or programming in general, feel free to get in touch and make suggestions.

The code continues...

2006-02-15T14:43:00.000Z

Ok, its definately less than perfect, but its a good start.
Using the gotoxy() function, I've got it to display the rough position of the 'planet' on the screen. It doesn't show the sun but it's assumed that is at the center.
The numbers are the number of seconds left of the simulation. It starts at 70, but they overwrite each other.
It's worked better than I expected. Now I need to put a slight delay on the while loop so that I can see it's progress better. Then I'll research into graphics programs.

More code

2006-02-13T22:58:00.000Z

Ok, I didn't work on the programme today, all I've got is:
/* Test of the gotoxy() function */
#include
#include
main()
{
gotoxy(10, 10);
printf("O");
}
This is probably the single least useful program ever written. What does it do? It repositions the cursor on the MS-Dos prompt.
The reason for writing this at all is because currently my gravity simulator only outputs the numbers, and the MS dod prompt can only show 52 lines. I need to output as a graphic, but at the moment I don't know how (It doesn't seem to be in the C version 4 library reference book). One option I've been looking at is a program called Delphi which I got free a while back, but that's another thing to learn.
I had hoped to get it finished today, but it got a lot harder. Hopefully I can get the graphics hooked up before school starts again, then look into calculus.

What the Hell?

2006-02-12T20:51:00.000Z

The unthinkable has happened. I've posted on my blog
(well, I did warn you in the description)
Anyway, I need to talk about programming, and this seems the best place.
Ok, I'm trying to simulate the effects of gravity on an object in a C program.
This is it so far:
#include
#include
#define GRAVITY 6.67 /* This needs to be changed to 6.67e-11 */
main()
{
long sunmass, planetmass, cycles;
float pX, pY, fX, fY, vX, vY, f, n;
/* Set starting Conditions */
planetmass = 1;
sunmass = 10;
vX = 0;
vY = 0;
printf("Initial X co-ordinate\n");
scanf("%f", &pX);
printf("Initial Y co-ordinate\n");
scanf("%f", &pY);
printf("Number of seconds\n");
scanf("%d", &cycles);
printf("%4.2f, %4.2f, %d\n", pX, pY, cycles);
/* Main process */
while ((cycles > 0) && (pX != 0) && (pY != 0)) /* Last two statements are required to avoid dividing by 0 */
{
n = (pX * pX)/(pY * pY);
f = (GRAVITY * sunmass * planetmass)/((pX*pX) + (pY*pY));
fX = sqrt(n * (f * f / (n + 1)));
fY = sqrt(f * f / (n + 1));
if (pX > 0) /* These 8 lines allow for negative values of pX and pY */
vX = vX - (fX / planetmass);
else vX = vX + (fX / planetmass);
if (pY > 0) vY = vY - (fY / planetmass);
else vY = vY + (fY / planetmass);
pX = pX + vX;
pY = pY + vY;
printf("x=%4.2f, y=%4.2f vX=%4.2f, vY=%4.2f, fX=%4.2f, fY=%4.2f, f=%4.2f, t=%d\n", pX, pY, vX, vY, fX, fY, f, cycles);
if ( (pX <> -1)) /* These 4 lines prevent a bug where after passing (0,0), the planet accelerates rapidly. */
pX = 0;
if ((pY <> -1))
pY = 0;
--cycles;
}
printf("End of Simulation\n");
}
Apologies for the messiness, it didn't copy across properly.
Pretty impressive for learning to write in C two days ago, hmm?

The problem I'm faced with now is that gravity is only calculated every second in the simulation. This has led to some blatant physics errors, such as violation of the conservation of energy principle etc.
I could just calculate it more often, but that won't solve the basic problem. I suspect that this is why Newton invented fluxions (calculus to the rest of us). So I nowhave to learn that too. Wonderful. Oh well, it was in my New Years resolution...

Feedback

2005-12-07T18:10:00.000Z

A couple of people (real people, not internet one) have mentioned that they feel this blog is too depressing. I'll take that as a compliment to my ability to portray the world realistically.
Wasn't that depressing.
Anyway, what I actually want to say is that Civilization 4 (http://2kgames.com/civ4/home.htm) is a great game. I've been unable to tear myself away from it to do anything useful or important on my compute since I installed it. Very addictive.

Grief

2005-10-31T15:40:00.000Z

Someone I knew fairly well died last week, and I've only just found out. My trombone teacher Niel was killed in an accident. I had a lot of respect for him.
This is the first time someone I've know well has died, and it's quite a shock. Since I'm not religious, I've got no illusions that his soul will go to heaven or anything like that, so possibly it's harder on me than it could be. Writing this helps though. As long as people remember him though, his life hasn't been a waste.
His funeral is tomorrow. I've run out of words.

Forum members required

2005-10-13T21:48:00.000Z

One of my friends has now got a website at http://www.gameradar.bravehost.com. If you're interested, sign up for the forum. Go on... you know you want too.

Edit: Also check out http://www.robonline.tk/

Return of the Lost Blog!

2005-10-07T21:44:00.000Z

Well, it's been a while since I updated this (bloody hell: 7 months!). To tell the truth I'd forgotten about it. It's not really telling anyone anything important, so I guess it doesn't matter.
I ought to say how much I respect the people who are risking their lives to get news out of China and other oppressive countries. Freedom of Information is one of the greatest things about the internet, and is sometimes all that keeps my faith in humanity going.
It's got a lot to go against. From what I've read of George Bush (admittedly my sources aren't exactly unbiased but honestly: "I call upon all nations to stop these terrorist killers. Thank You. Now watch this drive." That borders on the sick), and of events in China, the Middle East and the US, it seems the world is sliding. Groups with in the UK scare me too (UKIP for example) There were a couple of days where a while back where I was scared of everything.
Still it's hard to believe that the world will have a new Dark Age. The point hasn't really been driven home to me yet that everything could collapse around me. Let's hope it doesn't happen.

How can we be sure?

2005-03-07T22:36:00.000Z

I've been thinking about right and wrong lately. Some of the things I believe are right are for logical reasons, and about keeping people safe. Others... I can see no reason for them, but they still seem right to me. Is it because of my upbringing, or is it human nature. Is human nature just an excuse for our personal failings. And most importantly, can we change?

If the answers to these questions show we have little choice over our actions and thoughts, I see little point in living.

Sci-fi

2005-02-06T21:21:00.000Z

Alastair Reynold's books just get more and more depressing as they go on. Revelation Space ends fairly hopefully, in Redemption Ark they achieve something, but in Absolution Gap, there doesn't seem to be any chance of a happy ending. However, I haven't finished it yet, so I'll just have to wait and see.
Oh, and I saw I, Robot today. Excellent film, manages to cover many of the points in Asimov's stories, and entails both the Robots as Pathos and Robots as Menace ideas. Susan Calvin could have been better though.

The pointlessness of it...

2005-02-06T17:58:00.000Z

English coursework really depresses me.
Only 3 more sections to go...

Post Script

2005-02-03T22:47:00.000Z

I should really mention some of the Webcomics I read, just cause I think they're cool. Both the art and the writing is usually great.
General:
MacHall
PvP
Warhammer 40K:
Golden Throne

The future...

2005-02-03T22:30:00.000Z

Now that I've finally finished my homework, I can write some more.
Occasionally I worry about the future. As I get older, things are becoming more and more complex, and my various plans for when I'm an adult look like they're going to much more difficult than I anticipated. Maybe I'll talk about them sometime. Meanwhile, with Global warming posing a constant threat, I wonder if the human race has a future.
Hopefully when we get into space, we'll have a chance.
With a bit of luck, that's what SpaceShipOne and the beginnings of commercial space flight will achieve. One of the ambitions I mentioned before is to go into Space. Still, if it doesn't happen in my lifetime, something else important will. Perhaps the development of AI, or servitor Robots. Maybe a second information Revolution, or a revolution of something not yet dreamed of. Maybe neural interfaces, but they're probably too far into the future.
On the other hand, it's possible that I will be in the last generation of humanity. I hope not, and I don't think we're quite stupid enough to wipe ourselves out but you never know...
The near future is probably going to be a very depressing and amazing place.

Damn Homework

2005-02-03T19:40:00.000Z

Got Homework, so I can't say much. I really shouldn't leave it all until last minute like this. Well, at least the coursework doesn't have to be in until Monday...
Sometimes, I hate my life.

I wish I had a better computer...

2005-02-02T20:51:00.000Z

Unfortunately, the Pentium 4 I am supposed to be getting is not working (well it's a bit more complicated than that, but never mind). Currently I have to make do with a Pentium 2 with a graphics card that's a joke. The two games that I most want to run, Black and White and Dawn of War, do not run in any playable way. In addition, I very much doubt that Freelancer is supposed to be composed mainly of yellow, pink and green. At least it's playable. With a bit of luck, it should be ready in a month or two. Until then I'll just have to watch Babylon 5 and paint my Warhammer. My Howling Banshees beckon...

Moon landings a hoax? I think not.

2005-02-01T18:44:00.000Z

I found an excellent site which disproves most, if not all, evidence that the moonlandings were a hoax. Here it is.

Babylon 5, Stargate SG1 or Firefly? That is the question.

2005-02-01T18:33:00.000Z

The above three are definitely my three favourite TV programs. I doubt I will ever decide which I like most, but I can try.
Babylon 5 is definitely the most meaningful, as it is not only a realistic portrayal of life on a space station, but it usually has a moral. Stargate has lasted the longest, being now in its 7th or 8th Season, and has some brilliant characters. Firefly has the most different and therefore most intriguing picture of the future, and the mysteries left by its early shutdown are still waiting to be answered (I hear there is a film planned).
It doesn't really matter, they're all brilliant.

Intro - Hello World

2005-01-14T06:40:00.000Z

Finally! It took me ages to remember what the Conjoiners in Alastair Reynold's books called the beginning of their culture. This is my first Blog, and I'm hoping I can write about some of the things that are important to me, such as Space flight, global warming and science. I think I've said enough.

Transenlightenment complete!

2005-01-13T22:37:00.000Z

Test

2005-01-12T12:36:00.000Z

Checking Implants...
Receiving Thoughts...
Network Ready...