MATLAB helper function to load IMU data into matrices

load_imu_data.m

function [ imu_data, gps_data ] = load_imu_data( file_name )
%load data from txt file containing IMU output
%written by Shao Zhou billyzs.728[at] gmail.com
%   imu_data is n * 13 matrix that contains data fileds in the following sequence:
%   Time
%   Acceleration (x, y, z) in m/s
%   Angular Velocity (p, q, r) in rad/s
%   Magnetic field strength (x, y, z) in muT
%   Roll, Pitch, Yaw in deg

%   imu_data is m * 6 matrix that contains data fileds in the following sequence:
%   Time
%   GPS Lat in DDMM.MMMM
%   GPS Long in DDMM.MMMM
%   GPS Altitude in cm
%   GPS Speed in knots 
%   GPS Heading


l = sum(fileread(file_name) == 10) - 1; % count the number of data lines in the file by counting how many ASCII #10 (EOL) markers

id = fopen(file_name);
% imu data:
imu_data = csvread(file_name, 1, 0, [1, 0, l+1, 12]);
fclose(id);

%gps data:
gps_data = zeros(l, 6);
id = fopen(file_name, 'r');
format_spec = '%f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %f, %d';
n = 1;
c = 1;
line = fgetl(id);
while n <= l
    line = fgetl(id);
    if sum(line == ',') == 18 % if line contains gps data
        m = textscan(line, format_spec);
        m = cell2mat(m(1,1:18));
        gps_data(c, :) = [m(1,1), m(1, 14:18)];
        c = c + 1;
    end
    n = n+1;
end
gps_data = gps_data(1:c-1, :);
fclose(id);
end

main_script.m

% make sure txt file is in the same folder as this script
[imu_data, gps_data] = load_imu_data('your_file.txt');