random sineblip wave help

[Linguininess]

hello! so I am trying to come up with an expression that combines the random and sin functions. I am trying to mimic something like morse code. It's either on or off....but with a falloff. Can someone help? Thanks

[animatrix]

Hi,

You can write something like this:

float radius = ch("radius");
float amp = ch("amplitude");
float seed = ch("seed");
int count = chi("count");
for ( int i = 0; i < count; ++i )
{
    float r = rand ( i + 34.13 + seed );
    vector p = primuv ( 0, "P", 0, r );
    float d = distance ( p, @P );
    float d2 = fit ( d, 0, radius, 0, PI );
    float y = amp + sin ( d2 + 0.5 * PI ) * amp;
    
    if ( d < radius )
        @P.y += y;
}

[Linguininess]

this is great, thanks! how would I configure this setup to output the x value of this curve to just a single float value to be plugged into a parameter? 

[animatrix]

There are many ways, but the easiest is to sample the resulting curve using a float parameter like this:

primuv("../attribwrangle1/", 0, "P", 1, ch("pos"), 0)

This would be the expression you use in your parameter. Then you can control where to sample using another float parameter (normalized) called pos for example. This could be the current time also if you want, or you can animate the curve while sampling the same location on the curve.