Rem the purple wave is made out of two simple sinosoidal waves

fastgraphics

for t = 1 to 1000 step 0.1

clg

for n = 1 to 30 step 0.1

r=30*sin(t+n*0.2)

b=10*sin(t+n*0.8)

p= r+b

color red

circle 10*n,r+250,3

color blue

circle 10*n,b+200,3

color purple

circle 10*n,p+100,3

next n

refresh

next t