Basic Vector Field Maker Bases off principles of eigenvalues and eigenvectors. I believe the one being displayed is a unstable saddle point Try 1,3,-1,-1 for a Center Try 1,-4,1,2 for an unstable spiral Also see a properly made one: https://anvaka.github.io/fieldplay/?cx=-0.010000000000000009&cy=-0.006350000000000008&w=0.6262&h=0.6262&dt=0.001&fo=0.998&dp=0.009&cm=2&vf=%2F%2F%20p.x%20and%20p.y%20are%20current%20coordinates%0A%2F%2F%20v.x%20and%20v.y%20is%20a%20velocity%20at%20point%20p%0Avec2%20get_velocity%28vec2%20p%29%20%7B%0A%20%20vec2%20v%20%3D%20vec2%280.%2C%200.%29%3B%0A%0A%20%20%2F%2F%20change%20this%20to%20get%20a%20new%20vector%20field%0A%20%20v.x%20%3D%20%28p.x%29%20%2B%20%20%284.0%20*%20p.y%29%3B%0A%20%20v.y%20%3D%20%282.0%20*%20p.x%29%20%2B%20%20%28-1.0%20*%20p.y%29%3B%0A%0A%20%20return%20v%3B%0A%7D&code=%2F%2F%20p.x%20and%20p.y%20are%20current%20coordinates%0A%2F%2F%20v.x%20and%20v.y%20is%20a%20velocity%20at%20point%20p%0Avec2%20get_velocity%28vec2%20p%29%20%7B%0A%20%20vec2%20v%20%3D%20vec2%280.%2C%200.%29%3B%0A%0A%20%20%2F%2F%20change%20this%20to%20get%20a%20new%20vector%20field%0A%20%20v.x%20%3D%20%28p.x%29%20%2B%20%20%284.0%20*%20p.y%29%3B%0A%20%20v.y%20%3D%20%282.0%20*%20p.x%29%20%2B%20%20%28-1.0%20*%20p.y%29%3B%0A%0A%20%20return%20v%3B%0A%7D
Learned how all this works in my DiffEq Class
