SUB Euler(x,y,vx,vy,t,A,g,dt,ncalc)    ! Euler-Cromer method
    LET v2 = vx*vx + vy*vy
    LET v = sqr(v2)
    LET ax = -A*v*vx
    LET ay = -g - A*v*vy
    LET vx = vx + ax*dt
    LET vy = vy + ay*dt
    LET x = x + vx*dt
    LET y = y + vy*dt
    LET t = t + dt
END SUB