diff --git a/theory/Multipoles/mesh_summary.tex b/theory/Multipoles/mesh_summary.tex index 69242300a4f45d4575e614b70180da552221aa69..3069257c8845804d9a307cc54fffec5e36e4ae8c 100644 --- a/theory/Multipoles/mesh_summary.tex +++ b/theory/Multipoles/mesh_summary.tex @@ -1,6 +1,23 @@ \subsection{Coupling the FMM to a mesh for periodic long-range forces} \label{ssec:mesh_summary} +\begin{equation} + S(x) = \frac{e^x}{1 + e^x} +\end{equation} + +\begin{align} + \varphi_s(r) &= \frac{1}{r}\left[2 - 2S\left(\frac{2r}{r_s}\right)\right] \nonumber\\ + &= \frac{1}{r}\left[2 - \frac{2e^{\frac{2r}{r_s}}}{1+e^{\frac{2r}{r_s}}}\right] +\end{align} +\begin{align} + |\mathbf{f}_s(r)| &= \frac{1}{r^2}\left[\frac{4r}{r_s}S'\left(\frac{2r}{r_s}\right) - 2S\left(\frac{2r}{r_s}\right) + 2\right] \nonumber \\ + &= \frac{1}{r^2}\left[\frac{4r}{r_s}\frac{e^{\frac{2r}{r_s}}}{(1+e^{\frac{2r}{r_s}})^2} - \frac{2e^{\frac{2r}{r_s}}}{1+e^{\frac{2r}{r_s}}} + 2\right] +\end{align} + +\begin{equation} + \tilde\varphi_l(k) = \frac{1}{k^2}\left[\frac{\upi}{2}kr_s\textrm{csch}\left(\frac{\upi}{2}kr_s\right) \right] +\end{equation} + \begin{figure} \includegraphics[width=\columnwidth]{potential_short.pdf} \caption{aa} @@ -9,7 +26,14 @@ \begin{figure} -\includegraphics[width=\columnwidth]{potential_long.pdf} +\includegraphics[width=\columnwidth]{force_short.pdf} \caption{bb} +\label{fig:fmm:force_short} +\end{figure} + + +\begin{figure} +\includegraphics[width=\columnwidth]{potential_long.pdf} +\caption{cc} \label{fig:fmm:potential_long} \end{figure} diff --git a/theory/Multipoles/plot_mesh.py b/theory/Multipoles/plot_mesh.py index f8432a993531ea9a06abc48b8e075c4ee112fce6..6706016f73b4b6251c6d517ec89eacbb7a469417 100644 --- a/theory/Multipoles/plot_mesh.py +++ b/theory/Multipoles/plot_mesh.py @@ -67,56 +67,42 @@ phi_newton = 1. / r phit_newton = 1. / k**2 force_newton = 1. / r**2 -def smoothstep(x): #S_2(x) - ret = 6*x**5 - 15*x**4 + 10*x**3 - #ret = 3*x**2 - 2*x**3 - ret[x < 0] = 0. - ret[x > 1] = 1. - return ret - def my_exp(x): - #return 1. + x + (x**2 / 2.) + (x**3 / 6.) + (x**4 / 24.) + (x**5 / 120.)# + (x**6 / 720.) - return exp(x) + return 1. + x + (x**2 / 2.) + (x**3 / 6.) + (x**4 / 24.) + (x**5 / 120.)# + (x**6 / 720.) + #return exp(x) + +def csch(x): # hyperbolic cosecant + return 1. / sinh(x) def sigmoid(x): - return 1. / (1. + 1./my_exp(x)) - #return x / sqrt(1. + x**2) + return my_exp(x) / (my_exp(x) + 1.) def d_sigmoid(x): return my_exp(x) / ((my_exp(x) + 1)**2) def swift_corr(x): - #return 2. * smoothstep(x/4. + 1./2.) - 1. - #return sigmoid(4. * x) return 2 * sigmoid( 4 * x ) - 1 -def d_swift_corr(x): - return 2 * d_sigmoid( 4 * x ) - -def csch(x): # hyperbolic cosecant - return 1. / sinh(x) - -figure() -x = linspace(-4, 4, 100) -plot(x, special.erf(x), '-', color=colors[0]) -plot(x, swift_corr(x), '-', color=colors[1]) -plot(x, x, '-', color=colors[2]) -ylim(-1.1, 1.1) -xlim(-4.1, 4.1) -#plot(x, exp(x), '-', color=colors[0]) -#plot(x, my_exp(x), '-', color=colors[1]) -savefig("temp.pdf") +#figure() +#x = linspace(-4, 4, 100) +#plot(x, special.erf(x), '-', color=colors[0]) +#plot(x, swift_corr(x), '-', color=colors[1]) +#plot(x, x, '-', color=colors[2]) +#ylim(-1.1, 1.1) +#xlim(-4.1, 4.1) +#savefig("temp.pdf") # Correction in real space corr_short_gadget2 = special.erf(r / (2.*r_s)) -corr_long_gadget2 = exp(-k**2*r_s**2) corr_short_swift = swift_corr(r / (2.*r_s)) -#corr_long_swift = k * r_s * math.pi / (2. * sinh(0.5 * math.pi * r_s * k)) -corr_long_swift = math.pi * k * r_s * csch(0.5 * math.pi * r_s * k) / 2. eta_short_gadget2 = special.erfc(r / 2.*r_s) + (r / (r_s * math.sqrt(math.pi))) * exp(-r**2 / (4.*r_s**2)) -eta_short_swift = (2. * r * d_swift_corr(r / (2.*r_s)) / r_s) - 2*sigmoid(2*r / (r_s)) + 2. +eta_short_swift = 4. * (r / r_s) * d_sigmoid(2. * r / r_s) - 2. * sigmoid(2 * r / r_s) + 2. + +# Corection in Fourier space +corr_long_gadget2 = exp(-k**2*r_s**2) +corr_long_swift = math.pi * k * r_s * csch(0.5 * math.pi * r_s * k) / 2. -# Shortrange term2 +# Shortrange term phi_short_gadget2 = (1. / r ) * (1. - corr_short_gadget2) phi_short_swift = (1. / r ) * (1. - corr_short_swift) force_short_gadget2 = (1. / r**2) * eta_short_gadget2 @@ -149,18 +135,17 @@ legend(loc="upper right", frameon=True, handletextpad=0.1, handlelength=3.2, fon # Correction subplot(312, xscale="log", yscale="log") -#plot(r_rs, np.ones(np.size(r)), '--', lw=1.4, color=colors[0]) +plot(r_rs, np.ones(np.size(r)), '--', lw=1.4, color=colors[0]) plot(r_rs, 1. - corr_short_gadget2, '-', lw=1.4, color=colors[2]) plot(r_rs, 1. - corr_short_swift, '-', lw=1.4, color=colors[3]) -#plot(r_rs, np.zeros(np.size(r)), 'k--', alpha=0.5, lw=0.5) -plot(r_rs, np.ones(np.size(r)), 'k--', alpha=0.5, lw=0.5) -plot(r_rs, np.ones(np.size(r))*0.01, 'k--', alpha=0.5, lw=0.5) +plot(r_rs, np.ones(np.size(r))*0.01, 'k:', alpha=0.5, lw=0.5) plot([1., 1.], [-1e5, 1e5], 'k-', alpha=0.5, lw=0.5) yticks([1e-2, 1e-1, 1], ["$0.01$", "$0.1$", "$1$"]) xlim(1.1*r_min/r_s, 0.9*r_max/r_s) ylim(3e-3, 1.5) -ylabel("$\\chi_s(r)$", labelpad=-3) +#ylabel("$\\chi_s(r)$", labelpad=-3) +ylabel("$\\varphi_s(r) \\times r$", labelpad=-2) # 1 - Correction subplot(313, xscale="log", yscale="log") @@ -168,12 +153,13 @@ plot(r_rs, corr_short_gadget2, '-', lw=1.4, color=colors[2]) plot(r_rs, corr_short_swift, '-', lw=1.4, color=colors[3]) plot([1., 1.], [1e-5, 1e5], 'k-', alpha=0.5, lw=0.5) -plot(r_rs, np.ones(np.size(r)), 'k--', alpha=0.5, lw=0.5) -plot(r_rs, np.ones(np.size(r))*0.01, 'k--', alpha=0.5, lw=0.5) +plot(r_rs, np.ones(np.size(r)), 'k:', alpha=0.5, lw=0.5) +plot(r_rs, np.ones(np.size(r))*0.01, 'k:', alpha=0.5, lw=0.5) xlim(1.1*r_min/r_s, 0.9*r_max/r_s) ylim(3e-3, 1.5) -ylabel("$1 - \\chi_s(r)$", labelpad=-2) +#ylabel("$1 - \\chi_s(r)$", labelpad=-2) +ylabel("$1 - \\varphi_s(r) \\times r$", labelpad=-2) yticks([1e-2, 1e-1, 1], ["$0.01$", "$0.1$", "$1$"]) xlabel("$r / r_s$", labelpad=-3) @@ -200,16 +186,17 @@ legend(loc="upper right", frameon=True, handletextpad=0.1, handlelength=3.2, fon # Correction subplot(312, xscale="log", yscale="log") +plot(r_rs, np.ones(np.size(r)), '--', lw=1.4, color=colors[0]) plot(r_rs, eta_short_gadget2, '-', lw=1.4, color=colors[2]) plot(r_rs, eta_short_swift, '-', lw=1.4, color=colors[3]) -plot(r_rs, np.ones(np.size(r)), 'k--', alpha=0.5, lw=0.5) -plot(r_rs, np.ones(np.size(r))*0.01, 'k--', alpha=0.5, lw=0.5) +plot(r_rs, np.ones(np.size(r))*0.01, 'k:', alpha=0.5, lw=0.5) plot([1., 1.], [-1e5, 1e5], 'k-', alpha=0.5, lw=0.5) yticks([1e-2, 1e-1, 1], ["$0.01$", "$0.1$", "$1$"]) xlim(1.1*r_min/r_s, 0.9*r_max/r_s) ylim(3e-3, 1.5) -ylabel("$\\eta_s(r)$", labelpad=-3) +#ylabel("$\\eta_s(r)$", labelpad=-3) +ylabel("$|\\mathbf{f}_s(r)|\\times r^2$", labelpad=-2) # 1 - Correction subplot(313, xscale="log", yscale="log") @@ -217,12 +204,13 @@ plot(r_rs, 1. - eta_short_gadget2, '-', lw=1.4, color=colors[2]) plot(r_rs, 1. - eta_short_swift, '-', lw=1.4, color=colors[3]) plot([1., 1.], [1e-5, 1e5], 'k-', alpha=0.5, lw=0.5) -plot(r_rs, np.ones(np.size(r)), 'k--', alpha=0.5, lw=0.5) -plot(r_rs, np.ones(np.size(r))*0.01, 'k--', alpha=0.5, lw=0.5) +plot(r_rs, np.ones(np.size(r)), 'k:', alpha=0.5, lw=0.5) +plot(r_rs, np.ones(np.size(r))*0.01, 'k:', alpha=0.5, lw=0.5) xlim(1.1*r_min/r_s, 0.9*r_max/r_s) ylim(3e-3, 1.5) -ylabel("$1 - \\eta_s(r)$", labelpad=-2) +#ylabel("$1 - \\eta_s(r)$", labelpad=-2) +ylabel("$1 - |\\mathbf{f}_s(r)|\\times r^2$", labelpad=-3) yticks([1e-2, 1e-1, 1], ["$0.01$", "$0.1$", "$1$"]) xlabel("$r / r_s$", labelpad=-3) @@ -231,7 +219,7 @@ savefig("force_short.pdf") ################################################################################################## figure() -subplot(211, xscale="log", yscale="log") +subplot(311, xscale="log", yscale="log") # Potential plot(k_rs, phit_newton, '--', lw=1.4, label="${\\rm Newtonian}$", color=colors[0]) @@ -245,22 +233,35 @@ legend(loc="lower left", frameon=True, handletextpad=0.1, handlelength=3.2, font xlim(1.1*r_min/ r_s, 0.9*r_max / r_s) ylim(1.1/r_max**2, 0.9/r_min**2) ylabel("$\\tilde{\\varphi_l}(k)$", labelpad=-3) +yticks([1e-4, 1e-2, 1e0, 1e2], ["$10^{-4}$", "$10^{-2}$", "$10^{0}$", "$10^{2}$"]) - -subplot(212, xscale="log", yscale="log") +subplot(312, xscale="log", yscale="log") # Potential normalized plot(k_rs, phit_newton * k**2, '--', lw=1.4, label="${\\rm Newtonian}$", color=colors[0]) plot(k_rs, phit_long_gadget2 * k**2, '-', lw=1.4, label="${\\rm Gadget}$", color=colors[2]) plot(k_rs, phit_long_swift * k**2, '-', lw=1.4, label="${\\rm SWIFT}$", color=colors[3]) -plot(k_rs, -phit_long_swift * k**2, ':', lw=1.4, label="${\\rm SWIFT}$", color=colors[3]) plot([1., 1.], [1e-5, 1e5], 'k-', alpha=0.5, lw=0.5) -plot(r_rs, np.ones(np.size(r))*0.01, 'k--', alpha=0.5, lw=0.5) +plot(r_rs, np.ones(np.size(r))*0.01, 'k:', alpha=0.5, lw=0.5) xlim(1.1*r_min/ r_s, 0.9*r_max / r_s) ylim(3e-3, 1.5) ylabel("$k^2 \\times \\tilde{\\varphi_l}(k)$", labelpad=-3) yticks([1e-2, 1e-1, 1], ["$0.01$", "$0.1$", "$1$"]) + +subplot(313, xscale="log", yscale="log") + +plot(k_rs, 1. - phit_long_gadget2 * k**2, '-', lw=1.4, label="${\\rm Gadget}$", color=colors[2]) +plot(k_rs, 1. - phit_long_swift * k**2, '-', lw=1.4, label="${\\rm SWIFT}$", color=colors[3]) +plot([1., 1.], [1e-5, 1e5], 'k-', alpha=0.5, lw=0.5) +plot(r_rs, np.ones(np.size(r)), 'k:', alpha=0.5, lw=0.5) +plot(r_rs, np.ones(np.size(r))*0.01, 'k:', alpha=0.5, lw=0.5) + +xlim(1.1*r_min/ r_s, 0.9*r_max / r_s) +ylim(3e-3, 1.5) +ylabel("$1 - k^2 \\times \\tilde{\\varphi_l}(k)$", labelpad=-3) +yticks([1e-2, 1e-1, 1], ["$0.01$", "$0.1$", "$1$"]) + xlabel("$k \\times r_s$", labelpad=0) savefig("potential_long.pdf")