how to get a wavy look like this

hi everyone i'm kinda newbie in grasshopper , i wanna know what would be the best approach to get a shape like the following image ?

i've come up with some stuffs by having some series of points in vertical direction, controlling them by sine waves(vertically, horizontally) through graph mapper and making a interpolate curve out of them .. but it's not exactly what i want .. i used some BREPS to pick the points and make them stand out but haven't reached to a decent curvature and look like this ..

you're technical opinions are so much welcomed and appreciated.. thanks a lot for your time..