Exploration of Projection Spaces
Source: UCI Machine Learning Repository
Publication: Anguita et al., 2013
Institution: Smartlab - University of Genoa
Purpose: HAR from smartphone sensors for ambient assisted living
Collection: Controlled lab environment, 30 volunteers (ages 19-48)
Samples
10,299
Features
561
Activities
6
Train/Test Split
70% (7,352) / 30% (2,947)
Static (3)
Dynamic (3)
Balanced distribution (~1,700 samples/activity)
Data Loading: Merged train/test splits (X_all, y_all)
Normalization: StandardScaler (zero mean, unit variance)
Label Encoding: Activity names → integers (0-5)
Features: All 561 pre-extracted features retained
Time domain: mean, std, mad, max, min, sma, energy, iqr, entropy
Frequency domain: FFT coefficients, spectral energy, entropy, skewness, kurtosis
Signal processing: Butterworth filter for body/gravity separation
Jerk signals: Time derivatives of acceleration and angular velocity
Combines high dimensionality (561D) with clear structure (6 activities). Pre-extracted features allow focus on visualization and pattern discovery rather than signal processing, perfect for comparing DR methods like PCA, t-SNE, UMAP, and autoencoders.