Sohen Patel
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Dimensionality reduction

Time Series with PCA and SVD

3

components retain about 99.9% of variance in global temperature data

Two very different datasets show how much shared structure a panel of time series really has.

What I did

  • Built country-by-year and station-by-year matrices from Berkeley Earth temperatures (about 234 countries, 1901 to 2012) and Canadian ozone readings (18 stations, 1995 to 2022).
  • Implemented PCA from the covariance matrix and SVD variants, then plotted scree curves and RMSE against number of components.
  • Global temperature is dominated by a few components; ozone needs many more, meaning weaker shared structure.

Stack

NumPyscikit-learnMatplotlib