API reference

simpthon

simpthon.body

class simpthon.body.Body(m, x, v)

class representing a body/particle

get_mass()

return mass of a body/particle

get_pos()

return position of a body/particle

get_vel()

return velocity of a body/particle

set_mass(m)

set mass of a body/particle as m

set_phase_space(x, v)

set phase space of a body/particle as \(\mathbf{x,v}\)

set_pos(x)

set position of a body/particle as \(\mathbf{x}\)

set_vel(v)

set velocity of a body/particle as \(\mathbf{v}\)

class simpthon.body.NBody

class representing a bunch of bodies or particles (N-body)

add(b)

append a body to bodies

member()

return a list of body in bodies

number()

return number of bodies

simpthon.body.mass(b)

mass of a body

Parameters:

b (class Body) – body.

Returns:

mass of a body.

Return type:

float

simpthon.body.pos(b)

position of a body

Parameters:

b (class Body) – body.

Returns:

position of a body.

Return type:

numpy array

simpthon.body.vel(b)

velocity of a body

Parameters:

b (class Body) – body.

Returns:

velocity of a body.

Return type:

numpy array

simpthon.body.angmom(b)

angular momentum per unit mass of body b

\[\mathbf{L} = \mathbf{r \times v}\]

Parameters:

b (class Body) – body.

Returns:

angular momentum per unit mass of a body.

Return type:

numpy array

simpthon.body.kinetic(b)

kinetic energy per unit mass of body b

\[K = \frac{1}{2} \mathbf{v} \cdot \mathbf{v}\]

Parameters:

b (class Body) – body.

Returns:

kinetic energy per unit mass of a body.

Return type:

float

simpthon.body.radius(b)

radius of position of a body b i.e. \(r=\sqrt{\mathbf{x}\cdot \mathbf{x}}\).

Args:

b (class Body): body.

Returns:

radius of position of a body.

Return type:

float

simpthon.body.vradial(b)

radial velocity

Parameters:

b (class Body) – body.

Returns:

radial velocity of a body.

Return type:

numpy array

simpthon.body.vtangent(b)

tangential velocity

Parameters:

b (class Body) – body.

Returns:

radial velocity of a body.

Return type:

numpy array

simpthon.body.omega(b)

angular frequency of body b

\[\Omega = \frac{v_{\mathrm{tangential}}}{r}\]

Parameters:

b (class Body) – body.

Returns:

angular frequency of a body.

Return type:

float

simpthon.integrator

class simpthon.integrator.integrator

integrator for solving dynamical sistem:

\[\frac{dv}{dt} = a(x)\]

\[\frac{dx}{dt} = v (t)\]

abstract integrate(v, ti, tf, dt, pot)

return time, position, and velocity from ti to tf.

abstract step(v, dt)

return position and velocity after 1 step

class simpthon.integrator.leapfrog(pot)

Bases: integrator

a Kick-Drift-Kick version of leapfrog integrator

class simpthon.integrator.Euler(pot)

Bases: integrator

Euler Method \(w(t+dt) = w(t) + dt f(w(t))\)

for \(w(t) = (x(t),v(t))\).

class simpthon.integrator.RungeKutta4(pot)

Bases: integrator

a Runge-Kutta 4th Order integrator

class simpthon.integrator.Forward4OSymplectic(pot)

Bases: integrator

a Forward 4th Order Symplectic Integrator (Chin & Chen, 2005)

simpthon.potential

class simpthon.potential.potential

abstract acc()

return vector acceleration \(a\) at given position \(x\).

abstract mass()

return scalar mass \(m\) inside radius \(r\).

abstract pot()

return scalar potential \(\Phi\) at given position \(x\).

abstract tid()

return tensor tidal force \(T\) at given position \(x\).

class simpthon.potential.potentials(pots=[])

Bases: potential

list of potential:

\[\Phi (x) = \Sigma_i \Phi_i (x).\]

class simpthon.potential.osilator(k, m)

Bases: potential

Harmonik oscilator potential:

\[\Phi (x) = \frac{1}{2} k x^2.\]

class simpthon.potential.pointmass(GM)

Bases: potential

Point mass potential:

\[\Phi (x) = -\frac{GM}{r}.\]

class simpthon.potential.plummer(GM, b)

Bases: potential

Plummer potential :

\[\Phi (x) = -\frac{GM}{\sqrt{r^2 + b^2}},\]

with \(b\) scale factor.

class simpthon.potential.jaffe(GM, b)

Bases: potential

Jaffe potential:

\[\Phi (x) = -\frac{GM}{b} \frac{\ln (1+r/b)}{(r/b)^2},\]

with \(b\) scale factor.

class simpthon.potential.cluster_potential(pot, X=array([0, 0, 0]))

Bases: potential

simpthon.hplot

simpthon.hplot.plot(x, y, label=['x', 'f(x)'], label_fontsize=20, style='-', xlim=[0, 0], ylim=[0, 0], hide_tick=True, hide_tick_label=True, save_fig=' ', dpi=150, plot_xaxis=False, plot_yaxis=False, remove_axis=False, legend_label=' ', legend_loc=-1, tight_layout=True, y2=' ', style2='r-.', legend_label2=' ', y3=' ', style3='g--', legend_label3=' ', texts=[[0, 0, ' ']])

plot given data x,y up to 3 graphs

Parameters:

• x (array_like) – data x-axis

• y (array_like) – data y-axis

• label (list, optional) – label of axes, e.g. [‘x’,f(x)’].

• style (str, optional) – style of plot, similar to matplotlib.pyplot.plot style.

• xlim (list, optional) – limit of x-axis, list of lower and upper limits

• ylim (list) – limit of y axis, list of lower and upper limits

• hide_tick (bool, optional) – do you want to hide tick?

• hide_tick_label (bool, optional) – do you want to hide tick label

• save_fig (str, optional) – filename for saving figure

• dpi (int, optional) – number of dots per inch

• plot_xaxis (bool, optional) – do you want to plot x-axis (y=0)?

• plot_yaxis (bool, optional) – plot y-axis (x=0)?

• remove_axis (bool, optional) – remove_axis?

• legend_label (str, optional) – label for legend

• legend_loc (int, optional) – location of legend

• tight_layout (bool, optional) – do you want to tight layout

• y2 (array_like, optional) – second data y

• style2 (str, optional) – style of 2nd data y

• legend_label2 (str, optional) – label for legend 2nd function.

• y3 (array_like, optional) – third data y.

• style3 (str, optional) – style of 3rd data y.

• legend_label3 (str, optional) – label for legend 3rd data y.

• texts (list, optional) – list of [x pos text,y pos text,text].

Returns:

figure – show figure and save it if save_fig given.

Return type:

matplotlib_object

simpthon.hplot.plotf(func, label=['x', 'f(x)'], label_fontsize=20, style='-', xlim=[0, 0], ylim=[0, 0], points=100, hide_tick=True, hide_tick_label=True, save_fig=' ', dpi=150, plot_xaxis=False, plot_yaxis=False, remove_axis=False, legend_label=' ', legend_loc=-1, tight_layout=True, func2=' ', style2='r-.', legend_label2=' ', func3=' ', style3='g--', legend_label3=' ', texts=[[0, 0, ' ']])

plot given function

Parameters:

• func (function) – function

• label (list, optional) – label of axes, e.g. [‘x’,f(x)’].

• style (str, optional) – style of plot, similar to matplotlib.pyplot.plot style.

• xlim (list, optional) – limit of x-axis, list of lower and upper limits

• ylim (list) – limit of y axis, list of lower and upper limits

• points (int) – number of datum.

• hide_tick (bool, optional) – do you want to hide tick?

• hide_tick_label (bool, optional) – do you want to hide tick label

• save_fig (str, optional) – filename for saving figure

• dpi (int, optional) – number of dots per inch

• plot_xaxis (bool, optional) – do you want to plot x-axis (y=0)?

• plot_yaxis (bool, optional) – plot y-axis (x=0)?

• remove_axis (bool, optional) – remove_axis?

• legend_label (str, optional) – label for legend

• legend_loc (int, optional) – location of legend

• tight_layout (bool, optional) – do you want to tight layout

• func2 (function, optional) – second function

• style2 (str, optional) – style of 2nd function

• legend_label2 (str, optional) – label for legend 2nd function.

• func3 (function, optional) – third function y.

• style3 (str, optional) – style of 3rd function.

• legend_label3 (str, optional) – label for legend 3rd function.

• texts (list, optional) – list of [x pos text,y pos text,text].

Returns:

figure – show figure and save it if save_fig given.

Return type:

matplotlib_object