3D scatter plots

[Catfish4]

I want to create 3D scatter plots of the PRNG's in the C++11 random library for amusement.

With inspiration from the Internet^* my current algorithm looks like:

x = random() % max
y = random() % max
z = random() % max

while (do more dots)
{
    Vertex3i(x, y, z)
    x = y
    y = z
    z = random() % max
}

I don't like it, mostly because of the modulo. How should I do things?

^* http://www.de-brauwer.be/wiki/wikka.php?wakka=PyOpenGLScatter

[z05DSL3A]

Catfish4 wrote:

I don't like it, mostly because of the modulo. How should I do things?

Are the 'things' generating random numbers? If so, take a look at 'Random Number Generation in C++11'^[1]
________________________________________________________
[1] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3551.pdf

[Catfish4]

Are the 'things' generating random numbers?

No. Sorry for not being clear enough. (Thanks for the link though, which I will read.)

My question was: what is a better algorithm for generating the 3D points in the scatter plot?
I ask this because by using modulo, information is lost.

So how else can I create the random points for the plot? Should I scale them down by a factor of say 1000 and use double?

[z05DSL3A]

I ask this because by using modulo, information is lost.

This is why I was thinking you where asking about generating randon numbers, std::uniform_real_distribution it what I was thinking as a replacement for the modulo op.

[Catfish4]

Thanks again for the link. That PDF even exemplified the modulo method I've been using as an anti-pattern. The more you re-learn...

Now the resulting plots are nice. I still don't fully understand what I'm seeing, but I guess herein lies the decay of autumn.

If anybody wants the horrible code (based NeHe Lesson 7, and for Visual Studio 2012), here it is:
http://filebin.ca/x2AEsCM4KmW/Lesson07-scatterplots.zip

I suggest you edit the screen_width and screen_height constants before building.
After that, use the arrow keys to rotate, and Page Up and Page Down to zoom.