Source code for pyrfu.pyrf.mean_bins
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# 3rd party imports
import numpy as np
import xarray as xr
__author__ = "Louis Richard"
__email__ = "louisr@irfu.se"
__copyright__ = "Copyright 2020-2023"
__license__ = "MIT"
__version__ = "2.4.2"
__status__ = "Prototype"
[docs]def mean_bins(inp0, inp1, bins: int = 10):
r"""Computes mean of values of y corresponding to bins of x.
Parameters
----------
inp0 : xarray.DataArray
Time series of the quantity of corresponding to the bins.
inp1 : xarray.DataArray
Time series of the quantity to compute the binned mean.
bins : int, Optional
Number of bins.
Returns
-------
out : xarray.Dataset
Dataset with :
* bins : xarray.DataArray
bin values of the x variable.
* data : xarray.DataArray
Mean values of y corresponding to each bin of x.
* sigma : xarray.DataArray
Standard deviation.
Examples
--------
>>> import numpy
>>> from pyrfu import mms, pyrf
Time interval
>>> tint = ["2019-09-14T07:54:00.000", "2019-09-14T08:11:00.000"]
Spacecraft indices
>>> mms_list = numpy.arange(1,5)
Load magnetic field and electric field
>>> r_mms, b_mms = [[] * 4 for _ in range(2)]
>>> for mms_id in range(1, 5):
>>> r_mms.append(mms.get_data("R_gse", tint, mms_id))
>>> b_mms.append(mms.get_data("B_gse_fgm_srvy_l2", tint, mms_id))
>>>
Compute current density, etc
>>> j_xyz, _, b_xyz, _, _, _ = pyrf.c_4_j(r_mms, b_mms)
Compute magnitude of B and J
>>> b_mag = pyrf.norm(b_xyz)
>>> j_mag = pyrf.norm(j_xyz)
Mean value of J for 10 bins of B
>>> m_b_j = pyrf.mean_bins(b_mag, j_mag)
"""
assert isinstance(inp0, xr.DataArray), "inp0 must be xaray.DataArray"
assert isinstance(inp1, xr.DataArray), "inp1 must be xaray.DataArray"
assert inp0.ndim == 1, "inp0 must be a scalar"
assert inp1.ndim == 1, "inp1 must be a scalar"
x_sort = np.sort(inp0.data)
x_edge = np.linspace(x_sort[0], x_sort[-1], bins + 1)
y_avg, y_std = [np.zeros(bins), np.zeros(bins)]
for i in range(bins):
idx_left = inp0.data > x_edge[i]
idx_right = inp0.data < x_edge[i + 1]
y_bins = inp1.data[idx_left * idx_right]
y_avg[i], y_std[i] = [np.mean(y_bins), np.std(y_bins)]
bins = x_edge[:-1] + np.median(np.diff(x_edge)) / 2
out_dict = {
"data": (["bins"], y_avg),
"sigma": (["bins"], y_std),
"bins": bins,
}
out = xr.Dataset(out_dict)
return out