"""
meca - Plot focal mechanisms.
"""
import numpy as np
import pandas as pd
from pygmt.clib import Session
from pygmt.exceptions import GMTError, GMTInvalidInput
from pygmt.helpers import build_arg_list, fmt_docstring, kwargs_to_strings, use_alias
def convention_code(convention, component="full"):
"""
Determine the convention code for focal mechanisms.
The convention code can be used in meca's -S option.
Parameters
----------
convention : str
The focal mechanism convention. Can be one of the following:
- ``"aki"``: Aki and Richards
- ``"gcmt"``: Global Centroid Moment Tensor
- ``"partial"``: Partial focal mechanism
- ``"mt"``: Moment tensor
- ``"principal_axis"``: Principal axis
Single letter convention codes like ``"a"`` and ``"c"`` are also
supported but undocumented.
component : str
The component of the focal mechanism. Only used when ``convention`` is
``"mt"`` or ``"principal_axis"``. Can be one of the following:
- ``"full"``: Full moment tensor
- ``"deviatoric"``: Deviatoric moment tensor
- ``"dc"``: Double couple
Returns
-------
str
The single-letter convention code used in meca's -S option.
Examples
--------
>>> convention_code("aki")
'a'
>>> convention_code("gcmt")
'c'
>>> convention_code("partial")
'p'
>>> convention_code("mt", component="full")
'm'
>>> convention_code("mt", component="deviatoric")
'z'
>>> convention_code("mt", component="dc")
'd'
>>> convention_code("principal_axis", component="full")
'x'
>>> convention_code("principal_axis", component="deviatoric")
't'
>>> convention_code("principal_axis", component="dc")
'y'
>>> for code in ["a", "c", "m", "d", "z", "p", "x", "y", "t"]:
... assert convention_code(code) == code
>>> convention_code("invalid")
Traceback (most recent call last):
...
pygmt.exceptions.GMTInvalidInput: Invalid convention 'invalid'.
>>> convention_code("mt", "invalid") # doctest: +NORMALIZE_WHITESPACE
Traceback (most recent call last):
...
pygmt.exceptions.GMTInvalidInput:
Invalid component 'invalid' for convention 'mt'.
"""
# Codes for focal mechanism formats determined by "convention"
codes1 = {"aki": "a", "gcmt": "c", "partial": "p"}
# Codes for focal mechanism formats determined by both "convention" and
# "component"
codes2 = {
"mt": {"deviatoric": "z", "dc": "d", "full": "m"},
"principal_axis": {"deviatoric": "t", "dc": "y", "full": "x"},
}
if convention in codes1:
return codes1[convention]
if convention in codes2:
if component not in codes2[convention]:
raise GMTInvalidInput(
f"Invalid component '{component}' for convention '{convention}'."
)
return codes2[convention][component]
if convention in {"a", "c", "m", "d", "z", "p", "x", "y", "t"}:
return convention
raise GMTInvalidInput(f"Invalid convention '{convention}'.")
def convention_name(code):
"""
Determine the name of a focal mechanism convention from its code.
Parameters
----------
code : str
The single-letter convention code.
Returns
-------
str
The name of the focal mechanism convention.
Examples
--------
>>> convention_name("a")
'aki'
>>> convention_name("aki")
'aki'
"""
name = {
"a": "aki",
"c": "gcmt",
"p": "partial",
"z": "mt",
"d": "mt",
"m": "mt",
"x": "principal_axis",
"y": "principal_axis",
"t": "principal_axis",
}.get(code)
return name if name is not None else code
def convention_params(convention):
"""
Return the list of focal mechanism parameters for a given convention.
Parameters
----------
convention : str
The focal mechanism convention. Can be one of the following:
- ``"aki"``: Aki and Richards
- ``"gcmt"``: Global Centroid Moment Tensor
- ``"partial"``: Partial focal mechanism
- ``"mt"``: Moment tensor
- ``"principal_axis"``: Principal axis
Returns
-------
list
The list of focal mechanism parameters.
"""
return {
"aki": ["strike", "dip", "rake", "magnitude"],
"gcmt": [
"strike1",
"dip1",
"rake1",
"strike2",
"dip2",
"rake2",
"mantissa",
"exponent",
],
"mt": ["mrr", "mtt", "mff", "mrt", "mrf", "mtf", "exponent"],
"partial": ["strike1", "dip1", "strike2", "fault_type", "magnitude"],
"principal_axis": [
"t_value",
"t_azimuth",
"t_plunge",
"n_value",
"n_azimuth",
"n_plunge",
"p_value",
"p_azimuth",
"p_plunge",
"exponent",
],
}[convention]
@fmt_docstring
@use_alias(
A="offset",
B="frame",
C="cmap",
E="extensionfill",
Fr="labelbox",
G="compressionfill",
J="projection",
L="outline",
N="no_clip",
R="region",
T="nodal",
V="verbose",
W="pen",
c="panel",
p="perspective",
t="transparency",
)
@kwargs_to_strings(R="sequence", c="sequence_comma", p="sequence")
def meca( # noqa: PLR0912, PLR0913, PLR0915
self,
spec,
scale,
convention=None,
component="full",
longitude=None,
latitude=None,
depth=None,
plot_longitude=None,
plot_latitude=None,
event_name=None,
**kwargs,
):
r"""
Plot focal mechanisms.
Full option list at :gmt-docs:`supplements/seis/meca.html`
{aliases}
Parameters
----------
spec : str, 1-D array, 2-D array, dict, or pd.DataFrame
Data that contain focal mechanism parameters.
``spec`` can be specified in either of the following types:
- *str*: a file name containing focal mechanism parameters as
columns. The meaning of each column is:
- Columns 1 and 2: event longitude and latitude
- Column 3: event depth (in km)
- Columns 4 to 3+n: focal mechanism parameters. The number of columns
*n* depends on the choice of ``convention``, which will be
described below.
- Columns 4+n and 5+n: longitude, latitude at which to place
beachball. Using ``0 0`` will plot the beachball at the longitude,
latitude given in columns 1 and 2. [optional and requires
``offset=True`` to take effect].
- Text string to appear near the beachball [optional].
- *1-D array*: focal mechanism parameters of a single event.
The meanings of columns are the same as above.
- *2-D array*: focal mechanism parameters of multiple events.
The meanings of columns are the same as above.
- *dictionary or pd.DataFrame*: The dictionary keys or pd.DataFrame
column names determine the focal mechanism convention. For
different conventions, the following combination of keys are allowed:
- ``"aki"``: *strike, dip, rake, magnitude*
- ``"gcmt"``: *strike1, dip1, rake1, strike2, dip2, rake2, mantissa,*
*exponent*
- ``"mt"``: *mrr, mtt, mff, mrt, mrf, mtf, exponent*
- ``"partial"``: *strike1, dip1, strike2, fault_type, magnitude*
- ``"principal_axis"``: *t_value, t_azimuth, t_plunge, n_value,
n_azimuth, n_plunge, p_value, p_azimuth, p_plunge, exponent*
A dictionary may contain values for a single focal mechanism or
lists of values for multiple focal mechanisms.
Both dictionary and pd.DataFrame may optionally contain
keys/column names: ``latitude``, ``longitude``, ``depth``,
``plot_longitude``, ``plot_latitude``, and/or ``event_name``.
If ``spec`` is either a str, a 1-D array or a 2-D array, the
``convention`` parameter is required so we know how to interpret the
columns. If ``spec`` is a dictionary or a pd.DataFrame,
``convention`` is not needed and is ignored if specified.
scale : float or str
*scale*\ [**+a**\ *angle*][**+f**\ *font*][**+j**\ *justify*]\
[**+l**][**+m**][**+o**\ *dx*\ [/\ *dy*]][**+s**\ *reference*].
Adjust scaling of the radius of the beachball, which is
proportional to the magnitude. By default, *scale* defines the
size for magnitude = 5 (i.e., scalar seismic moment
M0 = 4.0E23 dynes-cm). If **+l** is used the radius will be
proportional to the seismic moment instead. Use **+s** and give
a *reference* to change the reference magnitude (or moment), and
use **+m** to plot all beachballs with the same size. A text
string can be specified to appear near the beachball
(corresponding to column or parameter ``event_name``).
Append **+a**\ *angle* to change the angle of the text string;
append **+f**\ *font* to change its font (size,fontname,color);
append **+j**\ *justify* to change the text location relative
to the beachball [Default is ``"TC"``, i.e., Top Center];
append **+o** to offset the text string by *dx*\ /*dy*.
convention : str
Focal mechanism convention. Choose from:
- ``"aki"`` (Aki & Richards)
- ``"gcmt"`` (global CMT)
- ``"mt"`` (seismic moment tensor)
- ``"partial"`` (partial focal mechanism)
- ``"principal_axis"`` (principal axis)
Ignored if ``spec`` is a dictionary or pd.DataFrame.
component : str
The component of the seismic moment tensor to plot.
- ``"full"``: the full seismic moment tensor
- ``"dc"``: the closest double couple defined from the moment tensor
(zero trace and zero determinant)
- ``"deviatoric"``: deviatoric part of the moment tensor (zero trace)
longitude : float, list, or 1-D numpy array
Longitude(s) of event location(s). Must be the same length as the
number of events. Will override the ``longitude`` values
in ``spec`` if ``spec`` is a dictionary or pd.DataFrame.
latitude : float, list, or 1-D numpy array
Latitude(s) of event location(s). Must be the same length as the
number of events. Will override the ``latitude`` values
in ``spec`` if ``spec`` is a dictionary or pd.DataFrame.
depth : float, list, or 1-D numpy array
Depth(s) of event location(s) in kilometers. Must be the same length
as the number of events. Will override the ``depth`` values in ``spec``
if ``spec`` is a dictionary or pd.DataFrame.
plot_longitude : float, str, list, or 1-D numpy array
Longitude(s) at which to place beachball(s). Must be the same length
as the number of events. Will override the ``plot_longitude`` values
in ``spec`` if ``spec`` is a dictionary or pd.DataFrame.
plot_latitude : float, str, list, or 1-D numpy array
Latitude(s) at which to place beachball(s). List must be the same
length as the number of events. Will override the ``plot_latitude``
values in ``spec`` if ``spec`` is a dictionary or pd.DataFrame.
event_name : str, list of str, or 1-D numpy array
Text string(s), e.g., event name(s) to appear near the beachball(s).
List must be the same length as the number of events. Will override
the ``event_name`` labels in ``spec`` if ``spec`` is a dictionary
or pd.DataFrame.
labelbox : bool or str
[*fill*].
Draw a box behind the label if given. Use *fill* to give a fill color
[Default is ``"white"``].
offset : bool or str
[**+p**\ *pen*][**+s**\ *size*].
Offset beachball(s) to longitude(s) and latitude(s) specified in the
the last two columns of the input file or array, or by
``plot_longitude`` and ``plot_latitude`` if provided. A small circle
is plotted at the initial location and a line connects the beachball
to the circle. Use **+s**\ *size* to set the diameter of the circle
[Default is no circle]. Use **+p**\ *pen* to set the pen attributes
for this feature [Default is set via ``pen``]. The fill of the
circle is set via ``compressionfill`` or ``cmap``, i.e.,
corresponds to the fill of the compressive quadrants.
compressionfill : str
Set color or pattern for filling compressive quadrants
[Default is ``"black"``]. This setting also applies to the fill of
the circle defined via ``offset``.
extensionfill : str
Set color or pattern for filling extensive quadrants
[Default is ``"white"``].
pen : str
Set pen attributes for all lines related to beachball [Default is
``"0.25p,black,solid"``]. This setting applies to ``outline``,
``nodal``, and ``offset``, unless overruled by arguments passed to
those parameters. Draws circumference of beachball.
outline : bool or str
[*pen*].
Draw circumference and nodal planes of beachball. Use *pen* to set
the pen attributes for this feature [Default is set via ``pen``].
nodal : bool, int, or str
[*nplane*][/*pen*].
Plot the nodal planes and outline the bubble which is transparent.
If *nplane* is
- ``0`` or ``True``: both nodal planes are plotted [Default].
- ``1``: only the first nodal plane is plotted.
- ``2``: only the second nodal plane is plotted.
Use /*pen* to set the pen attributes for this feature [Default is
set via ``pen``].
For double couple mechanisms, ``nodal`` renders the beachball
transparent by drawing only the nodal planes and the circumference.
For non-double couple mechanisms, ``nodal=0`` overlays best
double couple transparently.
cmap : str
File name of a CPT file or a series of comma-separated colors (e.g.,
*color1,color2,color3*) to build a linear continuous CPT from those
colors automatically. The color of the compressive quadrants is
determined by the z-value (i.e., event depth or the third column for
an input file). This setting also applies to the fill of the circle
defined via ``offset``.
no_clip : bool
Do **not** skip symbols that fall outside the frame boundaries
[Default is ``False``, i.e., plot symbols inside the frame
boundaries only].
{projection}
{region}
{frame}
{verbose}
{panel}
{perspective}
{transparency}
"""
kwargs = self._preprocess(**kwargs)
# Convert spec to pandas.DataFrame unless it's a file
if isinstance(spec, dict | pd.DataFrame): # spec is a dict or pd.DataFrame
# determine convention from dict keys or pd.DataFrame column names
for conv in ["aki", "gcmt", "mt", "partial", "principal_axis"]:
if set(convention_params(conv)).issubset(set(spec.keys())):
convention = conv
break
else:
if isinstance(spec, dict):
msg = "Keys in dict 'spec' do not match known conventions."
else:
msg = "Column names in pd.DataFrame 'spec' do not match known conventions."
raise GMTError(msg)
# convert dict to pd.DataFrame so columns can be reordered
if isinstance(spec, dict):
# convert values to ndarray so pandas doesn't complain about "all
# scalar values". See
# https://github.com/GenericMappingTools/pygmt/pull/2174
spec = pd.DataFrame(
{key: np.atleast_1d(value) for key, value in spec.items()}
)
elif isinstance(spec, np.ndarray): # spec is a numpy array
if convention is None:
raise GMTInvalidInput("'convention' must be specified for an array input.")
# make sure convention is a name, not a code
convention = convention_name(convention)
# Convert array to pd.DataFrame and assign column names
spec = pd.DataFrame(np.atleast_2d(spec))
colnames = ["longitude", "latitude", "depth", *convention_params(convention)]
# check if spec has the expected number of columns
ncolsdiff = len(spec.columns) - len(colnames)
if ncolsdiff == 0:
pass
elif ncolsdiff == 1:
colnames += ["event_name"]
elif ncolsdiff == 2:
colnames += ["plot_longitude", "plot_latitude"]
elif ncolsdiff == 3:
colnames += ["plot_longitude", "plot_latitude", "event_name"]
else:
raise GMTInvalidInput(
f"Input array must have {len(colnames)} to {len(colnames) + 3} columns."
)
spec.columns = colnames
# Now spec is a pd.DataFrame or a file
if isinstance(spec, pd.DataFrame):
# override the values in pd.DataFrame if parameters are given
for arg, name in [
(longitude, "longitude"),
(latitude, "latitude"),
(depth, "depth"),
(plot_longitude, "plot_longitude"),
(plot_latitude, "plot_latitude"),
(event_name, "event_name"),
]:
if arg is not None:
spec[name] = np.atleast_1d(arg)
# Due to the internal implementation of the meca module, we need to
# convert the following columns to strings if they exist
if "plot_longitude" in spec.columns and "plot_latitude" in spec.columns:
spec["plot_longitude"] = spec["plot_longitude"].astype(str)
spec["plot_latitude"] = spec["plot_latitude"].astype(str)
if "event_name" in spec.columns:
spec["event_name"] = spec["event_name"].astype(str)
# Reorder columns in DataFrame to match convention if necessary
# expected columns are:
# longitude, latitude, depth, focal_parameters,
# [plot_longitude, plot_latitude] [event_name]
newcols = ["longitude", "latitude", "depth", *convention_params(convention)]
if "plot_longitude" in spec.columns and "plot_latitude" in spec.columns:
newcols += ["plot_longitude", "plot_latitude"]
if kwargs.get("A") is None:
kwargs["A"] = True
if "event_name" in spec.columns:
newcols += ["event_name"]
# reorder columns in DataFrame
if spec.columns.tolist() != newcols:
spec = spec.reindex(newcols, axis=1)
# determine data_format from convention and component
data_format = convention_code(convention=convention, component=component)
# Assemble -S flag
kwargs["S"] = f"{data_format}{scale}"
with Session() as lib:
with lib.virtualfile_in(check_kind="vector", data=spec) as vintbl:
lib.call_module(module="meca", args=build_arg_list(kwargs, infile=vintbl))