Commit 741d05e0 authored by Matthieu Schaller's avatar Matthieu Schaller
Browse files

Merge branch 'gravity_documentation' into 'master'

Small cosmetic improvements to the documentation of the FMM code.



See merge request !432
parents e778f1ef 30e71b68
......@@ -52,7 +52,7 @@ colors=['#4477AA', '#CC6677', '#DDCC77', '#117733']
# Parameters
r_s = 2.
r_min = 1e-2
r_min = 3e-2
r_max = 1.5e2
# Radius
......@@ -68,35 +68,56 @@ phit_newton = 1. / k**2
force_newton = 1. / r**2
def my_exp(x):
return 1. + x + (x**2 / 2.) + (x**3 / 6.) + (x**4 / 24.) + (x**5 / 120.)# + (x**6 / 720.)
return 1. + x + (x**2 / 2.) + (x**3 / 6.) + (x**4 / 24.) + (x**5 / 120.) + (x**6 / 720.)
#return exp(x)
def term(x): # 1 / (1 + e^x)
return 1. / (1. + exp(x))
def my_term(x): # 1 / (1 + e^x)
#return 0.5 - 0.25 * x + (x**3 / 48.) - (x**5 / 480)
return 1. / (1. + my_exp(x))
def csch(x): # hyperbolic cosecant
return 1. / sinh(x)
def sigmoid(x):
return my_exp(x) / (my_exp(x) + 1.)
return exp(x) * term(x)
def d_sigmoid(x):
return my_exp(x) / ((my_exp(x) + 1)**2)
return exp(x) * term(x)**2
def my_sigmoid(x):
#return my_exp(x) / (my_exp(x) + 1.)
return my_exp(x) * my_term(x)
def my_d_sigmoid(x):
#return my_exp(x) / ((my_exp(x) + 1)**2)
return my_exp(x) * my_term(x)**2
def swift_corr(x):
return 2 * sigmoid( 4 * x ) - 1
#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")
def swift_corr2(x):
return 2 * my_sigmoid( 4 * x ) - 1
figure()
x = linspace(-4, 4, 100)
plot(x, special.erf(x), '-', color=colors[2])
plot(x, swift_corr(x), '-', color=colors[3])
plot(x, swift_corr2(x), '-.', color=colors[3])
plot(x, x, '-', color=colors[0])
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_short_swift = swift_corr(r / (2.*r_s))
eta_short_gadget2 = special.erfc(r / 2.*r_s) + (r / (r_s * math.sqrt(math.pi))) * exp(-r**2 / (4.*r_s**2))
corr_short_swift = swift_corr(r / (2.*r_s))
corr_short_swift2 = swift_corr2(r / (2.*r_s))
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 = 4. * (r / r_s) * d_sigmoid(2. * r / r_s) - 2. * sigmoid(2 * r / r_s) + 2.
eta_short_swift2 = 4. * (r / r_s) * my_d_sigmoid(2. * r / r_s) - 2. * my_sigmoid(2 * r / r_s) + 2.
# Corection in Fourier space
corr_long_gadget2 = exp(-k**2*r_s**2)
......@@ -105,8 +126,10 @@ corr_long_swift = math.pi * k * r_s * csch(0.5 * math.pi * r_s * k) / 2.
# Shortrange term
phi_short_gadget2 = (1. / r ) * (1. - corr_short_gadget2)
phi_short_swift = (1. / r ) * (1. - corr_short_swift)
phi_short_swift2 = (1. / r ) * (1. - corr_short_swift2)
force_short_gadget2 = (1. / r**2) * eta_short_gadget2
force_short_swift = (1. / r**2) * eta_short_swift
force_short_swift2 = (1. / r**2) * eta_short_swift2
# Long-range term
phi_long_gadget2 = (1. / r ) * corr_short_gadget2
......@@ -125,6 +148,7 @@ subplot(311, xscale="log", yscale="log")
plot(r_rs, phi_newton, '--', lw=1.4, label="${\\rm Newtonian}$", color=colors[0])
plot(r_rs, phi_short_gadget2, '-', lw=1.4, label="${\\rm Gadget}$", color=colors[2])
plot(r_rs, phi_short_swift, '-', lw=1.4, label="${\\rm SWIFT}$", color=colors[3])
plot(r_rs, phi_short_swift2, '-.', lw=1.4, color=colors[3])
plot([1., 1.], [1e-5, 1e5], 'k-', alpha=0.5, lw=0.5)
xlim(1.1*r_min/ r_s, 0.9*r_max / r_s)
......@@ -138,8 +162,11 @@ subplot(312, xscale="log", yscale="log")
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, 1. - corr_short_swift2, '-.', lw=1.4, color=colors[3])
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)
plot([-1, -1], [-1, -1], 'k-', lw=1.2, label="${\\textrm{Exact}~e^x}$")
plot([-1, -1], [-1, -1], 'k-.', lw=1.2, label="${6^\\textrm{th}~\\textrm{order~series}~e^x}$")
yticks([1e-2, 1e-1, 1], ["$0.01$", "$0.1$", "$1$"])
xlim(1.1*r_min/r_s, 0.9*r_max/r_s)
......@@ -147,10 +174,13 @@ ylim(3e-3, 1.5)
#ylabel("$\\chi_s(r)$", labelpad=-3)
ylabel("$\\varphi_s(r) \\times r$", labelpad=-2)
legend(loc="center left", frameon=False, handletextpad=0.1, handlelength=2.2, fontsize=7)
# 1 - Correction
subplot(313, xscale="log", yscale="log")
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(r_rs, corr_short_swift2, '-.', 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)
......@@ -161,7 +191,7 @@ ylim(3e-3, 1.5)
#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)
xlabel("$r / r_s$", labelpad=1)
savefig("potential_short.pdf")
......@@ -175,6 +205,7 @@ subplot(311, xscale="log", yscale="log")
plot(r_rs, force_newton, '--', lw=1.4, label="${\\rm Newtonian}$", color=colors[0])
plot(r_rs, force_short_gadget2, '-', lw=1.4, label="${\\rm Gadget}$", color=colors[2])
plot(r_rs, force_short_swift, '-', lw=1.4, label="${\\rm SWIFT}$", color=colors[3])
plot(r_rs, force_short_swift2, '-.', lw=1.4, color=colors[3])
plot([1., 1.], [1e-5, 1e5], 'k-', alpha=0.5, lw=0.5)
xlim(1.1*r_min/ r_s, 0.9*r_max / r_s)
......@@ -189,8 +220,11 @@ 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, eta_short_swift2, '-.', lw=1.4, color=colors[3])
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)
plot([-1, -1], [-1, -1], 'k-', lw=1.2, label="${\\textrm{Exact}~e^x}$")
plot([-1, -1], [-1, -1], 'k-.', lw=1.2, label="${6^\\textrm{th}~\\textrm{order~series}~e^x}$")
yticks([1e-2, 1e-1, 1], ["$0.01$", "$0.1$", "$1$"])
xlim(1.1*r_min/r_s, 0.9*r_max/r_s)
......@@ -198,10 +232,13 @@ ylim(3e-3, 1.5)
#ylabel("$\\eta_s(r)$", labelpad=-3)
ylabel("$|\\mathbf{f}_s(r)|\\times r^2$", labelpad=-2)
legend(loc="center left", frameon=False, handletextpad=0.1, handlelength=2.2, fontsize=7)
# 1 - Correction
subplot(313, xscale="log", yscale="log")
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(r_rs, 1. - eta_short_swift2, '-.', 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)
......@@ -212,7 +249,7 @@ ylim(3e-3, 1.5)
#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)
xlabel("$r / r_s$", labelpad=1)
savefig("force_short.pdf")
......@@ -225,7 +262,6 @@ subplot(311, xscale="log", yscale="log")
plot(k_rs, phit_newton, '--', lw=1.4, label="${\\rm Newtonian}$", color=colors[0])
plot(k_rs, phit_long_gadget2, '-', lw=1.4, label="${\\rm Gadget}$", color=colors[2])
plot(k_rs, phit_long_swift, '-', lw=1.4, label="${\\rm SWIFT}$", color=colors[3])
plot(k_rs, -phit_long_swift, ':', lw=1.4, color=colors[3])
plot([1., 1.], [1e-5, 1e5], 'k-', alpha=0.5, lw=0.5)
legend(loc="lower left", frameon=True, handletextpad=0.1, handlelength=3.2, fontsize=8)
......@@ -262,6 +298,6 @@ 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)
xlabel("$k \\times r_s$", labelpad=1)
savefig("potential_long.pdf")
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