Is the gigantic grocery chain Whole Foods, owned by the even more gigantic Amazon, now going after that most treasured NYC institution, the humble bodega? Maybe? Earlier this month, the vast conglomerate opened what they’re calling the Whole Foods Market Daily Shop, taking over a busy corner on Seventh Avenue and 25th Street and selling many of the usual bodega items with a fancier, organic, wellness-lifestyle-promoting spin. What even is a "Cranberry Energy Bagel Flat"? We refuse to find out. [ more › ] Gothamist https://ift.tt/2OtsDV2 March 28, 2019 at 08:57PM
Van der Pol’s differential equation is The equation describes a system with nonlinear damping, the degree of damping given by μ. If μ = 0 the system is linear and undamped, but for positive μ the system is nonlinear and damped. We will plot the phase portrait for the solution to Van der Pol’s equation in Python using SciPy’s new ODE solver ivp_solve . The function ivp_solve does not solve second-order systems of equations directly. It solves systems of first-order equations, but a second-order differential equation can be recast as a pair of first-order equations by introducing the first derivative as a new variable. Since y is the derivative of x , the phase portrait is just the plot of ( x , y ). If μ = 0, we have a simple harmonic oscillator and the phase portrait is simply a circle. For larger values of μ the solutions enter limiting cycles, but the cycles are more complicated than just circles. Here’s the Python code that made the plot. from scipy import linspace from ...
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