niimpy is a Python package for managing individual-level data. The
best way to describe it is to look at the big picture:
koota-server is a platform for collecting data from different sources, managing it for users and studies, and downloading it. Before downloading, it can be converted into tabular format.
Koota can provide data in the form of sqlite databases, which provides a nice interface for basic querying but still not enough for really efficient use. You can access these databases using the Python
sqlite3command line utility,
pandas.read_sql, and many other options.
niimpycan open these databases and provide a querying shortcut for basic operations, which saves you from having to write so much SQL yourself.
niimpyalso provides some more high-level operations, such as basic preprocessing/aggregation, visualizing data quality, and other transformations so that you can focus on your interesting work.
... but you need to do the real analysis work. If you make good, generalizable functions, they can be added to
Table of contents:
Only supports Python 3 (tested on 3.5 and above)
This is a normal Python package to install. It is not currently in PyPI, so can be installed manually
pip install https://github.com/digitraceslab/niimpy/archive/master.zip
First, you need to download the data. (Note: in normal use, this is
done for you). You can download in the
sqlite3 format from the
Koota interface and import yourself to sqlite, or use the
download_sync.sh script in Koota.
So, then usage is fairly simple:
data = niimpy.open('/path/to/database.sqlite') # Get hourly summaries of MurataBSN data (mean/std/count), hr and rr columns d = data.hourly(table='MurataBSN', user='rkr561Rkn-3t', columns=['hr', 'rr']) d.head(5) day hour count hr_mean hr_std hr_count rr_mean rr_std rr_count 2017-06-08 21:00:00 2017-06-08 21 3575 52.565145 12.561495 3575 6.165038 2.165948 3555
hourly function provides hourly summaries. The output is always
[pandas]( 2.243038 4.184948 3555) data frames, which are a somewhat
standard way of representing tabular-like data.
There are different functions to provide summaries of the data in different formats, but it is expected that you will be the one doing the core analysis with your own code.
Getting started with location data
All of the functions for reading, preprocessing, and feature extraction for location data is in
location.py. Currently implemented features are:
dist_total: total distance a person traveled in meter.
log_variance: variance is defined as sum of variance in latitudes and longitudes.
speed_max: statistics of speed (m/s). Speed, if not given, can be calculated by dividing the distance between two consequitive bins by their time difference.
n_bins: number of location bins that a user recorded in dataset.
n_static: number of static points. Static points are defined as bins whose speed is lower than a threshold.
n_moving: number of moving points. Equivalent to
n_bins - n_static.
n_home: number of static bins which are close to the person's home. Home is defined the place most visited during nights. More formally, all the locations recorded during 12 Am and 6 AM are clusterd and the center of largest cluster is assumed to be home.
max_dist_home: maximum distance from home.
n_sps: number of significant places. All of the static bins are clusterd using DBSCAN algorithm. Each cluster represents a Signicant Place (SP) for a user.
n_rare: number of rarely visited (referred as outliers in DBSCAN).
n_transitions: number of transitions between significant places.
n_top5: number of bins in the top
Ncluster. In other words,
n_top1shows the number of times the person has visited the most freqently visited place.
normalized_entropy: entropy of time spent in clusters. Normalized entropy is the entropy divided by the number of clusters.
import pandas as pd import niimpy import niimpy.location as nilo CONTROL_PATH = "PATH/TO/CONTROL/DATA" PATIENT_PATH = "PATH/TO/PATIENT/DATA" # Read data of control and patients from database location_control = niimpy.read_sqlite(CONTROL_PATH, table='AwareLocation', add_group='control', tz='Europe/Helsinki') location_patient = niimpy.read_sqlite(PATIENT_PATH, table='AwareLocation', add_group='patient', tz='Europe/Helsinki') # Concatenate the two dataframes to have one dataframe location = pd.concat([location_control, location_patient]) # Remove low-quality and outlier locations location = nilo.filter_location(location) # Downsample locations (median filter). Bin size is 10 minute. location = niimpy.util.aggregate(location, freq='10T', method_numerical='median') location = location.reset_index(0).dropna() # Feature extraction features = nilo.extract_features( lats=location['double_latitude'], lons=location['double_longitude'], users=location['user'], groups=location['group'], times=location.index, speeds=location['double_speed'] )
For now, see the included [docs/Introduction.ipynb] and [docs/Manual.ipynb] notebooks.
To learn about what converters exist and what they mean, see the Koota wiki, in particular the data sources section.
This is a pretty typical Python project with code and documentation as you might expect.
requirements-dev.txt contains some basic dev requirements, which
includes a editable dev install of niimpy itself (
pip install -e).
Run tests with:
Documentation is built with Sphinx:
cd docs make html # output in _build/html/
Enable nbdime Jupyter notebook diff and merge via git with:
nbdime config-git --enable
To learn about pandas, see its documentation. It is not the most clearly written documentation you will find, but you should try starting with the "Package overview" and "10 minutes to pandas" sections.