Audiovisuals with SC - Example08b - faster is slower

//Example08b - faster is slower
//only one line differs from Example08a.  the one in the main loop where we invert the mapping.
(
s.latency= 0.05;
s.waitForBoot{
       
        //--window setup
        var width= 640, height= 480;
        var w= Window("Example08b - faster is slower", Rect(99, 99, width, height), false);
        var u= UserView(w, Rect(0, 0, width, height));
       
        //--variables
        var pat= Pn(Pshuf(#[0, 0, 0, 0, 0.1, 0.25, 0.5, 0.75, 1, 1], 8), inf).asStream;
        var syn= SynthDef(\av, {|rate= 1|
                var x= Decay2.kr(Impulse.kr(rate), 0.01, 0.1, 2, 0.2);
                var z= LPF.ar(LFSaw.ar(#[300, 301, 80, 81]).mean, 2000, x);
                Out.ar(0, Pan2.ar(z));
        }, #[0.05]).play(s);            //short lag time to avoid clipping
        var posx= 0;
        var fre= 0;
       
        //--interface
        ~radius= 100;
        ~fps= 60;
        ~spreadx= 100;
       
        //--main loop
        u.drawFunc= {
                if(u.frame%~fps==0, {                                           //pick a new frequency only once per second
                        fre= pat.next;                                          //get the next value from the stream
                        syn.set(\rate, 1-fre*4+1);                              //send to the synth
                });
                posx= sin(u.frame*(fre+1)%50/50*2pi);
                Pen.translate(width*0.5, height*0.5);                   //offset drawing to the centre
                Pen.fillColor= Color.white;                                     //always fill with white color
                Pen.fillOval(Rect.aboutPoint(Point(posx*~spreadx, 0), ~radius, ~radius));
        };
       
        //--window management
        u.clearOnRefresh= true;
        u.background= Color.black;
        w.onClose= {syn.free};
        w.front;
        u.animate= true;
        CmdPeriod.doOnce({if(w.isClosed.not, {w.close})});
};
)

//change these while the program is running
~radius= 200;
~radius= 50;
~spreadx= 250;
~radius= 15;
~spreadx= 40;

//close the window to stop or press cmd+.