WJcd WJcn WJcs WJdc WJdn WJds WJnc WJnd WJsc WJsd WJsn WJtheta1 WJtheta1t WJtheta2 WJtheta2t WJtheta3 WJtheta3m1 WJtheta3m1t WJtheta3t WJtheta4 WJtheta4m1 WJtheta4m1t WJtheta4t

WJtheta4() Function WJtheta4 ( X As  Double, Q As  Double  ) Jacobi theta function θ4(x, q) Purpose This function computes the Jacobi theta function θ4. θ4(x, q) = 1 + 2Σ(-1)^n q^(n^2) cos(2nx) (Σ for n = 1 to ∞) Returns Jacobi theta function θ4(x, q). Parameters [in] X Argument x. [in] Q Argument q. (0 < Q < 1) Reference boost/math/special_functions