Extracts time-series acceleration from a csv of Raven amateur rocket altimeter data and plots it.

raven_extract.py

import matplotlib.pyplot as plt
import numpy as np
import csv

def extract_raven_accel(ravenfile, start_time = 0.0, end_time = 60.0, trim_head = 0, print_interval = 1000000):
    """
        Use this to pull acceleration data from a raven raw export file.
        Returns an Nx2 array of times (col 1) and accel values (col 2) in ft/s/s
        Assumes col 0 of the raven csv data is time, and col 15 is acceleration.
    """
    raven_accel_col = 15
    
    accel = np.zeros((1,2))
    # Read through the rows of the csv file and read accel time and accel values
    with open(ravenfile, 'r') as ravencsv:
        ravenreader = csv.reader(ravencsv, delimiter =',')
        i = 0
        for rowN, row in enumerate(ravenreader):
            # Trim the first N lines of the csv
            if rowN < trim_head:
                continue
            # Only extract accel values up to end_time
            if float(row[0]) <= end_time:
                if i > print_interval:
                    print row[0], rowN, row[15]
                    i = 0
                accel = np.append(accel, [[row[0], row[15]]], axis=0)
                i += 1
            else:
                break
            
    # Returns an Nx2 array with time and accel values as the columns
    return accel

#Plot the Raven accelerations
fig = plt.figure(1)
plt.subplot(211)
plt.scatter(accel[:,0], accel[:,1])