The Role of the Graphing Calculator in 2021 and Beyond

[Didier Lachieze]

(04-13-2021 02:58 PM)StephenG1CMZ Wrote:  

(04-13-2021 09:08 AM)toml_12953 Wrote:  What does RND 2-3 do? In standard BASICs, RND generates a random number in the range [0,1) but the 2-3 would be a syntax error.

If RND takes a single parameter I'd assume it would probably parse as
X +( 2*RND(2)) -3

Yes, from what I can see on my G850VS and in the English manual:
RND 2 returns either 1 or 2 randomly
so:
2*RND 2-3 returns either -1 or +1 randomly
and:
X=X+2*RND 2-3 increments or decrements X by 1, randomly

(04-13-2021 02:58 PM)StephenG1CMZ Wrote:  It's IF POINT(X, Y) NEXT Y
that has my confused.

POINT return the status of the specified point on the screen, so this loop looks for the highest value of Y for which the point (X,Y) is not set, so it looks for the top of the pixel column related to X to add a new pixel with PSET(X,Y).

Here is an example of the program output on my G850VS: