Loads Pupil Mobile IMu data into a pandas dataframe

pupil_mobile_imu_data.py

import numpy as np
import pandas as pd
 
G = 9.78033 
IMU_TYPE = np.dtype([
    ("time_s", "<f8"),
    *((f"accel_{d}", "<f4") for d in "xyz"),
    *((f"gyro_{d}", "<f4") for d in "xyz")
]) 

def load_imu(imu_path):
    return np.fromfile(imu_path, IMU_TYPE) 

def load_imu_df(imu_path):
    imu = load_imu(imu_path)
    imu["time_s"] -= imu["time_s"][0]
    df = pd.DataFrame(imu, columns=imu.dtype.names)
    df["time_s"] = pd.to_datetime(df["time_s"], unit="s")
    acc = df[[f"accel_{d}" for d in "xyz"]]
    energy = np.linalg.norm(acc, axis=1) - G
    df.insert(len(df.columns), "energy", energy)
    
    return df