Principal component analysis (PCA) is becoming a routine mathematical tool in several fields for data analysis,
dimensionality and noise reduction, data compression. The new branch of data analysis called as big data analysis or data
mining has emerged in which data in very large quantities, having large number of variables in the form of signal or an image
has to be processed. PCA is, usually the first step in data mining and automated decision making as a feature extraction
technique. The data may contain variables having different units in which they were measured. Data pre-processing plays an
important role in the final results of PCA.
