zZfM0mEtWku setxyrapport 25 setxunit 7.5 setborder -5 5 setxrange -5 5 setyrange jpegmode /nycspineandpain.com/bitcoin-mining-difficulty-explained.html">bitcoin mining difficulty explained</a> /gavinmarshalldental.com/can-i-buy-bitcoins-with-a-credit-card.html">can i buy bitcoins with a credit card</a> 1 1 settkstep .5 .5 setsubtkstep 2 2 setmkstep ticks subticks marks traceaxes axesarrow /R {settvar #rpn# a * Sin (k*t) } def 0 2 pi mul settrange gsave 0.75 setlinewidth continu bleu (R) courbepolar grestore