With more points points are less poor visible in plot. Why?

[Cornel]

Hi,

What is the reason that with N = 4000 I can see the points more pregnant, but with N = 5000 points are visible poor:

[StuartBruff]

Possibly because around 5000 points is when Mathcad changes the 2D plot behaviour.

If the number of data points is less than 5000, Mathcad uses one pixel torepresent one data point.  If there are 5000 or more data points, then Mathcad uses one pixel to represent one or more (near coincident) data points.  

Another side effect of "density plotting" is that the available trace formatting options for Symbols are (none) or solid circle only.  I'm guessing that a further side effect of density plotting is that it reduces the symbol size to 1 pixel (although this doesn't seem to appear in Help), even though Line Thickness is still a valid option.

Stuart

[Werner_E · Accepted solution]

---

@Cornel wrote:

Hi,

What is the reason that with N = 4000 I can see the points more pregnant, but with N = 5000 points are visible poor:

---

That's one of the limitations of Primes 3D plot.

The maximum number allowed seems to be 4999, so you have to set N to 4997 or lower because you are plotting N+2 points (guess your range is supposed to only run up to N-1, not N? Maybe even N-2 if N should denote the number of points and not the number of iteration steps.)

Another limitation of Primes 3D plot is that it will completely refuse to plot more than 40000 points. 😞

EDIT:

These limits are per trace limits, so as a workaround you could split your data and create two (or more) traces. Of course you may format and color them the same 😉