% Load data and display
load challenge_2_data.mat;
T = array2table(X,'VariableNames',participants,'RowNames',meas_names)
T = 2924 table
Compute the principal components of the dataset . Refer to Table 1 for a visual representation of
the data. Once you have computed the principal components, answer the following questions.
What is the dimension of each principal component? What is the significance of this dimension?
How many principal components are needed to adequately represent the original dataset? Justify
your reasoning with supporting calculations and plots. At the minimum, your justification should
include a bar graph showing the relative contribution of each principal component to the total
variance in the dataset.
% Enter your code for calculating the principal components and plotting the
% contributions from each component here:
P 1P 2P 3P 4P 5P 6P 7P 8P 9P 10P 11P 12P 13P 14P 15P 16P 17P 18P 19P 20P 21P 22P 23P
241 Distance
(m)54.166243.205052.167346.985353.657953.964550.963651.556449.406550.394734.056754.3
46147.739852.500753.624751.774349.350851.562953.569655.104552.706051.490947.116954.
26232 Ambulation Time
(sec)88.050036.440057.050038.4600108.0300116.620071.760050.020053.940063.100046.0800
87.370054.220066.890079.270057.020067.610069.310070.920066.100082.410048.890063.270
069.90003 Velocity
(cm/sec)61.5000118.600091.4000122.200049.700046.300071103.100091.600079.900073.90006
2.20008878.500067.600090.80007374.400075.500083.400064105.300074.500077.60004 Step
Count13066967011818110289837958150861031139091879910411680761105 Cadence
(steps/min)88.6000108.7000101109.200065.500093.100085.3000106.800092.300075.100075.5
00010395.200092.400085.500094.700080.800075.300083.800094.400084.500098.200072.1000
94.40006 Step Time (sec)
L0.68400.61100.59600.57100.96000.72800.81100.51700.61900.76600.80200.57000.60800.628
00.79200.66700.82700.78300.61800.59800.72900.66200.83900.62207 Step Length (cm)
L43.147062.368056.563067.367043.960045.799055.858058.395054.972056.265052.383039.72
6052.199052.306049.200055.923060.674054.335050.259053.987049.217066.824057.142045.3
6308 Step Time (sec)
R0.67000.50000.59300.53100.86900.56800.61600.60700.68000.83000.78700.59400.65100.669
00.61500.60000.66800.81100.79800.66800.69300.56700.82400.64909 Step Length (cm)
R40.139068.202052.210066.915047.037015.344045.123057.452063.972071.129064.632032.73
6058.529049.713045.801059.131048.460064.315057.320052.092042.027062.247067.682053.2
96010 Cycle Time (sec)
L1.34901.11001.18801.09901.82901.30901.42201.12401.30301.60101.58901.16601.25901.299
01.40001.26001.49801.58801.42101.26701.42401.23101.66301.271011 Cycle Time (sec)
R1.34701.10501.19501.10701.84201.29801.43701.12201.30401.60101.58701.16101.25601.297
01.41001.26601.49201.59301.41701.26601.42401.23801.66301.273012 Stride Length (cm)
L82.6850131.0970109.4710135.604091.651063.1200101.4760115.5490119.2550127.7270116.4
14072.5150110.7650102.112094.9320115.1840109.7780118.8840107.6140106.181091.369012
9.1110124.516098.805013.
Load data and displayload challenge_2_data.mat;T = array2table.pdf
1. % Load data and display
load challenge_2_data.mat;
T = array2table(X,'VariableNames',participants,'RowNames',meas_names)
T = 2924 table
Compute the principal components of the dataset . Refer to Table 1 for a visual representation of
the data. Once you have computed the principal components, answer the following questions.
What is the dimension of each principal component? What is the significance of this dimension?
How many principal components are needed to adequately represent the original dataset? Justify
your reasoning with supporting calculations and plots. At the minimum, your justification should
include a bar graph showing the relative contribution of each principal component to the total
variance in the dataset.
% Enter your code for calculating the principal components and plotting the
% contributions from each component here:
P 1P 2P 3P 4P 5P 6P 7P 8P 9P 10P 11P 12P 13P 14P 15P 16P 17P 18P 19P 20P 21P 22P 23P
241 Distance
(m)54.166243.205052.167346.985353.657953.964550.963651.556449.406550.394734.056754.3
46147.739852.500753.624751.774349.350851.562953.569655.104552.706051.490947.116954.
26232 Ambulation Time
(sec)88.050036.440057.050038.4600108.0300116.620071.760050.020053.940063.100046.0800
87.370054.220066.890079.270057.020067.610069.310070.920066.100082.410048.890063.270
069.90003 Velocity
(cm/sec)61.5000118.600091.4000122.200049.700046.300071103.100091.600079.900073.90006
2.20008878.500067.600090.80007374.400075.500083.400064105.300074.500077.60004 Step
Count13066967011818110289837958150861031139091879910411680761105 Cadence
(steps/min)88.6000108.7000101109.200065.500093.100085.3000106.800092.300075.100075.5
00010395.200092.400085.500094.700080.800075.300083.800094.400084.500098.200072.1000
94.40006 Step Time (sec)
L0.68400.61100.59600.57100.96000.72800.81100.51700.61900.76600.80200.57000.60800.628
00.79200.66700.82700.78300.61800.59800.72900.66200.83900.62207 Step Length (cm)
L43.147062.368056.563067.367043.960045.799055.858058.395054.972056.265052.383039.72
6052.199052.306049.200055.923060.674054.335050.259053.987049.217066.824057.142045.3
6308 Step Time (sec)
R0.67000.50000.59300.53100.86900.56800.61600.60700.68000.83000.78700.59400.65100.669
00.61500.60000.66800.81100.79800.66800.69300.56700.82400.64909 Step Length (cm)
R40.139068.202052.210066.915047.037015.344045.123057.452063.972071.129064.632032.73
2. 6058.529049.713045.801059.131048.460064.315057.320052.092042.027062.247067.682053.2
96010 Cycle Time (sec)
L1.34901.11001.18801.09901.82901.30901.42201.12401.30301.60101.58901.16601.25901.299
01.40001.26001.49801.58801.42101.26701.42401.23101.66301.271011 Cycle Time (sec)
R1.34701.10501.19501.10701.84201.29801.43701.12201.30401.60101.58701.16101.25601.297
01.41001.26601.49201.59301.41701.26601.42401.23801.66301.273012 Stride Length (cm)
L82.6850131.0970109.4710135.604091.651063.1200101.4760115.5490119.2550127.7270116.4
14072.5150110.7650102.112094.9320115.1840109.7780118.8840107.6140106.181091.369012
9.1110124.516098.805013 Stride Length (cm)
R82.7100130.8740109.0680132.285091.265062.7440101.7700116.0350119.3890127.8810117.4
17072.3630112.2410102.516095.3820115.3700108.8890118.6090108.2910106.260091.010013
0.7910125.659098.965014 HH Base Support (cm)
L12.77909.86809.36606.74508.531015.797019.676018.23206.74505.14608.895029.602016.786
04.29403.16604.337013.68306.630012.07307.93107.29402.84004.05903.1380
