p = 115792089237316195423570985008687907853269984665640564039457584007908834671663
$E4 = EllipticCurve(GF(p), [0,4])$
$E7 = EllipticCurve(GF(p), [0,7])$
base_x = 0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798
base_y = 0x483ADA7726A3C4655DA4FBFC0E1108A8FD17B448A68554199C47D08FFB10D4B8
#Basepoint of $y^2=x^3+7$
BP = E7(base_x, base_y, 1)$
#Point on $y^2=x^3+7$
Q = E([81119306557295043947776230900539651493257160932663731932698523086255548483211,69833235478127881789123626297864036834549011744885041054439092651501655231589])
#base point of $y^2=x3+4$
BasePoint2(
[44959049921401095561708555029356671875656137150174062590365663013295388555357, 83434812528180346320431259926231725911951822121210091498845843183726829396473])
- How to convert coordinates of $Q(x,y)$ on $y^2=x3+7$ to coordinates in $y^2=x3+4$ ? Code needed(SAGE, Python etc.).