Reading and Writing Files

Reading trajectory data

traja allows reading files via traja.parsers.read_file(). For example a CSV file trajectory.csv with the following contents:

x,y
1,1
1,2
1,3

Could be read in like:

import traja

df = traja.read_file('trajectory.csv')

read_file returns a TrajaDataFrame with access to all pandas and traja methods.

Any keyword arguments passed to read_file will be passed to pandas.read_csv().

Data frames can also be read with pandas pandas.read_csv() and then converted to TrajaDataFrames with:

import traja
import pandas as pd

df = pd.read_csv('data.csv')

# If x and y columns are named different than "x" and "y", rename them, eg:
df = df.rename(columns={"x_col": "x", "y_col": "y"}) # original column names x_col, y_col

# If the time column doesn't include "time" in the name, similarly rename it to "time"

trj = traja.TrajaDataFrame(df)

Writing trajectory data

Files can be saved using the built-in pandas pandas.to_csv().

df.to_csv('trajectory.csv')