Just have a variable holding the old value, to update at the end of draw() with the new value. Like pmouse, precisely.

delay() is rarely useful...
The idea is more like:

1. float oldLongitude;
2. void draw()
3. {
4.   // I suppose longitude is updated somewhere
5.   // [...]
6.   float d = dist(oldLongiture, longitude);
7.   // [...]
8.   oldLongitude = longitude; // Might check time to update only after some time is spent
9. }

hey PhiLho,

The processing dist() method takes in 4 variables. However, if you had your own method called dist() you could define how many variables you want. I think in the example above it was more about showing how to store a previous value, than about the what is happening in the dist() method. Are you trying to do something similar with storing a variable or with the dist() method?

I am; I have a line I am trying to draw with incoming OSC variable coordinates.

It is exactly the same idea, except you store the point (whatever its type) instead of a float.

1. SomePointClass previousPoint;
2. 
   
3. void draw()
4. {
5.   // ... (get newPoint from OSC)
6.  
7.   if (previousPoint != null)
8.   {
9.     line(previousPoint.getScreenX(width), previousPoint.getScreenY(height), newPoint.getScreenX(width), newPoint.getScreenY(height));
10.   }
11.   previousPoint = newPoint;
12. }

woah, nevermind. I just needed to rearrange a couple of methods. all is well.