while and for loops!

[zesty]

ok, so basically heres my problem...in my program i have to write to my output file column of time, against x(t)..so i have to output time[i] and x[i], where
time[0]=0 and x[0] is given by reader input.

but i have to only display time until some parameter known as p..But I cant seem to get it to stop when time[i]<p..it just keeps on listing time for all values up to the size of my array..with a while loop i can get time[i]<p but then my values of x[i] are all 0 which is cleary wrong..just need some tips on how to constuct the loops..at the moment it looks like this:

time[0]=0;
time_increment =1.0;
fprintf(output, "%f %f\n", time[0], x[0]);
 i=0;
  i++;
  while((time[i]>=0)&&(time[i] < p))
  {
   i++;
    
    time[i] = i*time_increment;
    v[i+1] = v[i] - (g*v[i] + w2*x[i])*time_increment + (1/m)*f[i]*time_increment;
    x[i+1] = x[i] + v[i+1]*time_increment;
  
	fprintf(output, "%f %f\n", time[i], x[i]);
  }

also, as u can see i cant seem to get it to display time[0] and x[0] automically for i=0, in my output file..how can i fix this?

thanx for any help at all!
}

my first draft i used a for loop, but i did not know what the statment to be evaluted could be other than time[i]<p, which clearly doesnt work for the for loop.

  for(i=0; time[i] <p; i++)
  {
 
   
 
    
    time[i] = i*time_increment;
    v[i+1] = v[i] - (g*v[i] + w2*x[i])*time_increment + (1/m)*f[i]*time_increment;
	x[i+1] = x[i] + v[i+1]*time_increment;
  
	fprintf(output, "%f %f\n", time[i], x[i]);
  }

[dwks]

You should avoid using variables called time -- time() is a function from <time.h>, and calling variables time hides time() and might make readers confused.

I'll quote a recent PM here:

A for loop of the form

for(initialization; condition; increment) {
    code;
}

is syntactically equivalent to a while loop of the form

initialization;
while(condition) {
    code;
    increment;
}

Perhaps that will help you figure out what to do . . . .

[Elysia]

As you can see, the forum messes up your code when you mix spaces and tabs - so don't! Stick to one and keep it that way. I recommend tabs.
Keep your indentation consistent! Don't indent one space at once space and two more spaces at one line in the same block! All should be the same - one tab for each block - no more, no less.
This is helpful in making others reading your code correctly. No one wants to go through a poorly indented code! Make yourself favor (and everyone else) - indent properly.

[dwks]

As you can see, the forum messes up your code when you mix spaces and tabs - so don't! Stick to one and keep it that way. I recommend tabs.

Actually, I don't. Here's why: if you go to edit code with spaces in the forum's quick or advanced reply boxes directly, you can type spaces enough to match the OP's indentation. However, typing a tab doesn't work: you just tab to the next widget or whatever. You have to copy a tab and paste it whenever you want to add a new line.

Not to mention that tabs are 8 spaces on this forum, which is usually more than (double?) what tabs are usually set to in our editors. Posts take up a lot of horizontal space this way; you might even have to end up scrolling sideways, depending on your screen etc.

Plus I always use spaces instead of tabs in all of my code anyway.

[Elysia]

Actually, I don't. Here's why: if you go to edit code with spaces in the forum's quick or advanced reply boxes directly, you can type spaces enough to match the OP's indentation. However, typing a tab doesn't work: you just tab to the next widget or whatever. You have to copy a tab and paste it whenever you want to add a new line.

So what does the have to do with it? You should be using tabs in your editor!
And there's a very handy extension for FF that allows you to insert tabs into text fields. Plus when I don't reply from home, I just open notepad, do a tab and copy it.
Problem solved.

Not to mention that tabs are 8 spaces on this forum, which is usually more than (double?) what tabs are usually set to in our editors. Posts take up a lot of horizontal space this way; you might even have to end up scrolling sideways, depending on your screen etc.

Forum problem. If you really want, you can use tabs -> spaces conversion for temporary posting of code on forum. But that doesn't mean you shouldn't use tabs in your editor.

Plus I always use spaces instead of tabs in all of my code anyway.

Well, I don't - I always use tabs and no exceptions and no spaces