# Source code for yt.visualization.particle_plots

"""
This is a simple mechanism for interfacing with Particle plots

"""

#-----------------------------------------------------------------------------
# Copyright (c) 2013, yt Development Team.
#
#
# The full license is in the file COPYING.txt, distributed with this software.
#-----------------------------------------------------------------------------

import numpy as np

from yt.visualization.fixed_resolution import \
ParticleImageBuffer
from yt.funcs import \
ensure_list, \
fix_axis
from yt.units.yt_array import YTArray
from .plot_window import \
get_axes_unit, \
get_window_parameters, \
PWViewerMPL
from yt.data_objects.profiles import \
create_profile
from yt.visualization.profile_plotter import \
PhasePlot

[docs]class ParticleAxisAlignedDummyDataSource(object):
_type_name = 'Particle'
_dimensionality = 2
_con_args = ('center', 'axis', 'width', 'fields', 'weight_field')
_tds_attrs = ()
_key_fields = []

def __init__(self, center, ds, axis, width, fields,
weight_field=None,
field_parameters=None, data_source=None):
self.center = center
self.ds = ds
self.axis = axis
self.width = width
self.weight_field = weight_field

if field_parameters is None:
self.field_parameters = {}
else:
self.field_parameters = field_parameters

LE = center - 0.5*YTArray(width)
RE = center + 0.5*YTArray(width)
self.dd = ds.region(center, LE, RE, fields,
field_parameters=field_parameters,
data_source=data_source)

fields = self.dd._determine_fields(fields)
self.fields = fields

def _determine_fields(self, *args):
return self.dd._determine_fields(*args)

[docs]    def get_field_parameter(self, name, default=None):
"""
This is typically only used by derived field functions, but
it returns parameters used to generate fields.
"""
if name in self.field_parameters:
return self.field_parameters[name]
else:
return default

[docs]class ParticleProjectionPlot(PWViewerMPL):
r"""Creates a particle plot from a dataset

Given a ds object, an axis to slice along, and a field name
string, this will return a PWViewerMPL object containing
the plot.

The plot can be updated using one of the many helper functions
defined in PlotWindow.

Parameters
----------
ds : Dataset
This is the dataset object corresponding to the
simulation output to be plotted.
axis : int or one of 'x', 'y', 'z'
An int corresponding to the axis to slice along (0=x, 1=y, 2=z)
or the axis name itself
fields : string, list or None
If a string or list, the name of the particle field(s) to be used
one the colorbar. If None, the particle positions will be indicated
using a fixed color, instead. Default is None.
color : 'b', 'g', 'r', 'c', 'm', 'y', 'k', or 'w'
One the matplotlib-recognized color strings.
The color that will indicate the particle locations
on the mesh. This argument is ignored if z_fields is
not None. Default is 'b'.
center : A sequence of floats, a string, or a tuple.
The coordinate of the center of the image. If set to 'c', 'center' or
left blank, the plot is centered on the middle of the domain. If set to
'max' or 'm', the center will be located at the maximum of the
('gas', 'density') field. Centering on the max or min of a specific
field is supported by providing a tuple such as ("min","temperature") or
("max","dark_matter_density"). Units can be specified by passing in *center*
as a tuple containing a coordinate and string unit name or by passing
in a YTArray. If a list or unitless array is supplied, code units are
assumed.
width : tuple or a float.
Width can have four different formats to support windows with variable
x and y widths.  They are:

==================================     =======================
format                                 example
==================================     =======================
(float, string)                        (10,'kpc')
((float, string), (float, string))     ((10,'kpc'),(15,'kpc'))
float                                  0.2
(float, float)                         (0.2, 0.3)
==================================     =======================

For example, (10, 'kpc') requests a plot window that is 10 kiloparsecs
wide in the x and y directions, ((10,'kpc'),(15,'kpc')) requests a
window that is 10 kiloparsecs wide along the x axis and 15
kiloparsecs wide along the y axis.  In the other two examples, code
units are assumed, for example (0.2, 0.3) requests a plot that has an
x width of 0.2 and a y width of 0.3 in code units.  If units are
provided the resulting plot axis labels will use the supplied units.
depth : A tuple or a float
A tuple containing the depth to project through and the string
key of the unit: (width, 'unit').  If set to a float, code units
are assumed. Defaults to the entire domain.
weight_field : string
The name of the weighting field.  Set to None for no weight.
axes_unit : A string
The name of the unit for the tick labels on the x and y axes.
Defaults to None, which automatically picks an appropriate unit.
If axes_unit is '1', 'u', or 'unitary', it will not display the
units, and only show the axes name.
origin : string or length 1, 2, or 3 sequence of strings
The location of the origin of the plot coordinate system.  This is
represented by '-' separated string or a tuple of strings.  In the
first index the y-location is given by 'lower', 'upper', or 'center'.
The second index is the x-location, given as 'left', 'right', or
'center'.  Finally, the whether the origin is applied in 'domain'
space, plot 'window' space or 'native' simulation coordinate system
is given. For example, both 'upper-right-domain' and ['upper',
'right', 'domain'] both place the origin in the upper right hand
corner of domain space. If x or y are not given, a value is inferred.
For instance, 'left-domain' corresponds to the lower-left hand corner
of the simulation domain, 'center-domain' corresponds to the center
of the simulation domain, or 'center-window' for the center of the
plot window. Further examples:

==================================     ============================
format                                 example
==================================     ============================
'{space}'                              'domain'
'{xloc}-{space}'                       'left-window'
'{yloc}-{space}'                       'upper-domain'
'{yloc}-{xloc}-{space}'                'lower-right-window'
('{space}',)                           ('window',)
('{xloc}', '{space}')                  ('right', 'domain')
('{yloc}', '{space}')                  ('lower', 'window')
('{yloc}', '{xloc}', '{space}')        ('lower', 'right', 'window')
==================================     ============================
fontsize : integer
The size of the fonts for the axis, colorbar, and tick labels.
field_parameters : dictionary
A dictionary of field parameters than can be accessed by derived
fields.
window_size : float
The size of the window on the longest axis (in units of inches),
including the margins but not the colorbar.
aspect : float
The aspect ratio of the plot.  Set to None for 1.
data_source : YTSelectionContainer Object
Object to be used for data selection.  Defaults to a region covering
the entire simulation.

Examples
--------

This will save an image the the file
'galaxy0030_Particle_z_particle_mass.png'

>>> p = yt.ParticleProjectionPlot(ds, 2, 'particle_mass')
>>> p.save()

"""
_plot_type = 'Particle'
_frb_generator = ParticleImageBuffer

def __init__(self, ds, axis, fields=None, color='b', center='c', width=None,
depth=(1, '1'), weight_field=None, axes_unit=None,
origin='center-window', fontsize=18, field_parameters=None,
window_size=8.0, aspect=None, data_source=None):
# this will handle time series data and controllers
ts = self._initialize_dataset(ds)
self.ts = ts
ds = self.ds = ts[0]
axis = fix_axis(axis, ds)
(bounds, center, display_center) = \
get_window_parameters(axis, center, width, ds)
if field_parameters is None:
field_parameters = {}

if axes_unit is None:
axes_unit = get_axes_unit(width, ds)

# if no fields are passed in, we simply mark the x and
# y fields using a given color. Use the 'particle_ones'
# field to do this. We also turn off the colorbar in
# this case.
self._use_cbar = True
splat_color = None
if fields is None:
fields = ['particle_ones']
weight_field = 'particle_ones'
self._use_cbar = False
splat_color = color

depth = ds.coordinates.sanitize_depth(depth)

x_coord = ds.coordinates.x_axis[axis]
y_coord = ds.coordinates.y_axis[axis]

width = np.zeros_like(center)
width[x_coord] = bounds[1] - bounds[0]
width[y_coord] = bounds[3] - bounds[2]
width[axis] = depth[0].in_units(width[x_coord].units)

ParticleSource = ParticleAxisAlignedDummyDataSource(center, ds, axis,
width, fields, weight_field,
field_parameters=field_parameters,
data_source=data_source)

PWViewerMPL.__init__(self, ParticleSource, bounds, origin=origin,
fontsize=fontsize, fields=fields,
window_size=window_size, aspect=aspect,
splat_color=splat_color)

self.set_axes_unit(axes_unit)

if self._use_cbar is False:
self.hide_colorbar()

[docs]class ParticlePhasePlot(PhasePlot):
r"""
Create a 2d particle phase plot from a data source or from
a yt.data_objects.profiles.ParticleProfile object.

Given a data object (all_data, region, sphere, etc.), an x field,
y field, and z field (or fields), this will create a particle plot
by depositing the particles onto a two-dimensional mesh, using either
nearest grid point or cloud-in-cell deposition.

Parameters
----------
data_source : YTSelectionContainer Object
The data object to be profiled, such as all_data, region, or
sphere.
x_field : str
The x field for the mesh.
y_field : str
The y field for the mesh.
z_fields : None, str, or list
If None, particles will be splatted onto the mesh,
but no colormap will be used.
If str or list, the name of the field or fields to
be displayed on the colorbar.
Default: None.
color : 'b', 'g', 'r', 'c', 'm', 'y', 'k', or 'w'
One the matplotlib-recognized color strings.
The color that will indicate the particle locations
on the mesh. This argument is ignored if z_fields is
not None.
Default : 'b'
x_bins : int
The number of bins in x field for the mesh.
Default: 800.
y_bins : int
The number of bins in y field for the mesh.
Default: 800.
weight_field : str
The field to weight by. Default: None.
deposition : str
Either 'ngp' or 'cic'. Controls what type of
interpolation will be used to deposit the
particle z_fields onto the mesh.
Default: 'ngp'
fontsize: int
Font size for all text in the plot.
Default: 18.
figure_size : int
Size in inches of the image.
Default: 8 (8x8)

Examples
--------

>>> import yt
"particle_position_y", ["particle_mass"],
...                          x_bins=800, y_bins=800)
>>> plot.save()

>>> # Change plot properties.
>>> plot.set_log('particle_mass', True)
>>> plot.set_unit('particle_position_x', 'Mpc')
>>> plot.set_unit('particle_velocity_z', 'km/s')
>>> plot.set_unit('particle_mass', 'Msun')

"""
_plot_type = 'ParticlePhase'

def __init__(self, data_source, x_field, y_field, z_fields=None,
color='b', x_bins=800, y_bins=800, weight_field=None,
deposition='ngp', fontsize=18, figure_size=8.0):

# if no z_fields are passed in, use a constant color
if z_fields is None:
self.use_cbar = False
self.splat_color = color
z_fields = ['particle_ones']

profile = create_profile(
data_source,
[x_field, y_field],
ensure_list(z_fields),
n_bins=[x_bins, y_bins],
weight_field=weight_field,
deposition=deposition)

type(self)._initialize_instance(self, data_source, profile, fontsize,
figure_size)

[docs]def ParticlePlot(ds, x_field, y_field, z_fields=None, color='b', *args,
**kwargs):
r"""
A factory function for
:class:yt.visualization.particle_plots.ParticleProjectionPlot
and :class:yt.visualization.profile_plotter.ParticlePhasePlot objects.
This essentially allows for a single entry point to both types of particle
plots, the distinction being determined by the fields passed in.

If the x_field and y_field combination corresponds to a valid, right-handed
spatial plot, an ParticleProjectionPlot will be returned. This plot
object can be updated using one of the many helper functions defined in
PlotWindow.

If the x_field and y_field combo do not correspond to a valid
ParticleProjectionPlot, then a ParticlePhasePlot. This object can be
modified by its own set of  helper functions defined in PhasePlot. We note
below which arguments are only accepted by ParticleProjectionPlot and
which arguments are only accepted by ParticlePhasePlot.

Parameters
----------

ds : :class:yt.data_objects.static_output.Dataset
This is the dataset object corresponding to the
simulation output to be plotted.
x_field : string
This is the particle field that will be plotted on the x-axis.
y_field : string
This is the particle field that will be plotted on the y-axis.
z_fields : string, list, or None.
If None, particles will be splatted onto the plot, but no colormap
will be used. The particle color will instead be determined by
the 'color' argument. If str or list, the name of the field or fields
to be displayed on the colorbar.
Default: None.
color : 'b', 'g', 'r', 'c', 'm', 'y', 'k', or 'w'
One the matplotlib-recognized color strings.
The color that will indicate the particle locations
on the plot. This argument is ignored if z_fields is
not None. Default is 'b'.
weight_field : string
The name of the weighting field.  Set to None for no weight.
fontsize : integer
The size of the fonts for the axis, colorbar, and tick labels.
data_source : YTSelectionContainer Object
Object to be used for data selection.  Defaults to a region covering
the entire simulation.
center : A sequence of floats, a string, or a tuple.
The coordinate of the center of the image. If set to 'c', 'center' or
left blank, the plot is centered on the middle of the domain. If set to
'max' or 'm', the center will be located at the maximum of the
('gas', 'density') field. Centering on the max or min of a specific
field is supported by providing a tuple such as ("min","temperature") or
("max","dark_matter_density"). Units can be specified by passing in *center*
as a tuple containing a coordinate and string unit name or by passing
in a YTArray. If a list or unitless array is supplied, code units are
assumed. This argument is only accepted by ParticleProjectionPlot.
width : tuple or a float.
Width can have four different formats to support windows with variable
x and y widths.  They are:

==================================     =======================
format                                 example
==================================     =======================
(float, string)                        (10,'kpc')
((float, string), (float, string))     ((10,'kpc'),(15,'kpc'))
float                                  0.2
(float, float)                         (0.2, 0.3)
==================================     =======================

For example, (10, 'kpc') requests a plot window that is 10 kiloparsecs
wide in the x and y directions, ((10,'kpc'),(15,'kpc')) requests a
window that is 10 kiloparsecs wide along the x axis and 15
kiloparsecs wide along the y axis.  In the other two examples, code
units are assumed, for example (0.2, 0.3) requests a plot that has an
x width of 0.2 and a y width of 0.3 in code units.  If units are
provided the resulting plot axis labels will use the supplied units.
This argument is only accepted by ParticleProjectionPlot.
depth : A tuple or a float
A tuple containing the depth to project through and the string
key of the unit: (width, 'unit').  If set to a float, code units
are assumed. Defaults to the entire domain. This argument is only
accepted by ParticleProjectionPlot.
axes_unit : A string
The name of the unit for the tick labels on the x and y axes.
Defaults to None, which automatically picks an appropriate unit.
If axes_unit is '1', 'u', or 'unitary', it will not display the
units, and only show the axes name.
origin : string or length 1, 2, or 3 sequence of strings
The location of the origin of the plot coordinate system.  This is
represented by '-' separated string or a tuple of strings.  In the
first index the y-location is given by 'lower', 'upper', or 'center'.
The second index is the x-location, given as 'left', 'right', or
'center'.  Finally, the whether the origin is applied in 'domain'
space, plot 'window' space or 'native' simulation coordinate system
is given. For example, both 'upper-right-domain' and ['upper',
'right', 'domain'] both place the origin in the upper right hand
corner of domain space. If x or y are not given, a value is inferred.
For instance, 'left-domain' corresponds to the lower-left hand corner
of the simulation domain, 'center-domain' corresponds to the center
of the simulation domain, or 'center-window' for the center of the
plot window. Further examples:

==================================     ============================
format                                 example
==================================     ============================
'{space}'                              'domain'
'{xloc}-{space}'                       'left-window'
'{yloc}-{space}'                       'upper-domain'
'{yloc}-{xloc}-{space}'                'lower-right-window'
('{space}',)                           ('window',)
('{xloc}', '{space}')                  ('right', 'domain')
('{yloc}', '{space}')                  ('lower', 'window')
('{yloc}', '{xloc}', '{space}')        ('lower', 'right', 'window')
==================================     ============================

This argument is only accepted by ParticleProjectionPlot.
window_size : float
The size of the window on the longest axis (in units of inches),
including the margins but not the colorbar. This argument is only
accepted by ParticleProjectionPlot.
aspect : float
The aspect ratio of the plot.  Set to None for 1. This argument is
only accepted by ParticleProjectionPlot.
x_bins : int
The number of bins in x field for the mesh. Defaults to 800. This
argument is only accepted by ParticlePhasePlot.
y_bins : int
The number of bins in y field for the mesh. Defaults to 800. This
argument is only accepted by ParticlePhasePlot.
deposition : str
Either 'ngp' or 'cic'. Controls what type of interpolation will be
used to deposit the particle z_fields onto the mesh. Defaults to 'ngp'.
This argument is only accepted by ParticlePhasePlot.
figure_size : int
Size in inches of the image. Defaults to 8 (product an 8x8 inch figure).
This argument is only accepted by ParticlePhasePlot.

Examples
--------

>>> p = yt.ParticlePlot(ds, 'particle_position_x', 'particle_position_y',
...                     'particle_mass', width=(0.5, 0.5))
>>> p.set_unit('particle_mass', 'Msun')
>>> p = yt.ParticlePlot(ds, 'particle_position_x', 'particle_velocity_z',
...                     color='g')

"""
dd = kwargs.get('data_source', None)
if dd is None:
dd = ds.all_data()
x_field = dd._determine_fields(x_field)[0]
y_field = dd._determine_fields(y_field)[0]

direction = 3
# try potential axes for a ParticleProjectionPlot:
for axis in [0, 1, 2]:
xax = ds.coordinates.x_axis[axis]
yax = ds.coordinates.y_axis[axis]
ax_field_template = 'particle_position_%s'
xf = ax_field_template % ds.coordinates.axis_name[xax]
yf = ax_field_template % ds.coordinates.axis_name[yax]
if (x_field[1], y_field[1]) == (xf, yf):
direction = axis
break

if direction < 3:
# Make a ParticleProjectionPlot
return ParticleProjectionPlot(ds, direction, z_fields, color,
*args, **kwargs)

# Does not correspond to any valid PlotWindow-style plot,