Source code for polyfemos.data.utils
# -*- coding: utf-8 -*-
# -----------------------------------------------------------------------------
# This file is part of Polyfemos.
#
# Polyfemos is free software: you can redistribute it and/or modify it under
# the terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 3 of the License, or any later version.
#
# Polyfemos is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License and
# GNU General Public License along with Polyfemos. If not, see
# <https://www.gnu.org/licenses/>.'
#
# Author: Henrik Jänkävaara
# -----------------------------------------------------------------------------
"""
Miscellanous data manipulation functions
:copyright:
2019, University of Oulu, Sodankyla Geophysical Observatory
:license:
GNU Lesser General Public License v3.0 or later
(https://spdx.org/licenses/LGPL-3.0-or-later.html)
"""
import numpy as np
[docs]def log10_decimation(data, maxn=100):
"""
Remove datapoints logarithmicly
remove every n datapoints starting from 0, ending maxn-1
n increases exponentially
Mainly used for logarithmic plotting where there are
too many datapoints to be properly plot
Returns decimated data as list
:type data: list or array-like
:param data: data array to be decimated
:type maxn: int
:param maxn: defines the amount of decimation made
:rtype: list
:return: Logarithmically decimated list
"""
len_ = len(data)
maxexp = np.log10(maxn)
exps = np.arange(0, maxexp, maxexp / len_)
indices = []
i = 0
while i < len_:
indices.append(i)
i += int(10 ** exps[i])
return [data[i] for i in indices]