Thread: Txt file and data storage

If all you're trying to do is figure out the shortest distance, then you don't need to record every distance and then sort them. You can just calculate one distance; if it's the shortest distance found so far, then record the set of points you used to calculate this distance and the actual distance.

Something like this.

Code:

        double value, min_value = distance(trajectories[0]);
        Paths::size_type min_index = 0;
        
        for(Paths::size_type i=1; i < trajectories.size(); i++) {
                value = distance(trajectories[x]);
                if(value < min_value) {
                        min_value = value;
                        min_index = i;
                }
        }
        
        // now trajectories[min_index] has the minimum Euclidean distace,
        // the exact value of which is recorded in min_value.

You'll have to write the distance() function, of course. That should be pretty easy, though.

[edit] Just use a for loop to loop through all the items in a Paths. Calculate (x1-x2)**2 for each pair of coordinates, as your Wiki page indicates, sum those values, and return the square root of the final sum . . . . [/edit]

Best of luck, I'm off.

Ok i have problem again right at the start. I don't know how to pass vector with index (vector[x]) as function argument. I did this:

Code:

double distance (Paths path[i]) {
	double dist, tmp;
	
	for (Dots::size_type j=0; j<path[i].size[];j++) { 
	
		tmp += pow((path[i][j].xt - path[i][++j].xt),2) + pow((path[i][j].yt - path[i][++j].yt),2);
	}
	dist = sqrt(tmp);
	return dist;
}

and during compiling i got error that i and path aren't declared in this scope of course. How can i pass it as argument? And i'm not sure about the ++j in the calculation line. In fact i'm quite sure that it is wrong. How can i access the next coordinate if not in this manner?