data processing for machine learning ---scratch pad

Grab the 1st three rows of data files to analyze:

cat ex2x.dat | awk 'NR >= 1  && NR <= 3 { print }' > ex2x.short.dat

cat ex2y.dat | awk 'NR >= 1  && NR <= 3 { print }' > ex2y.short.dat

https://stackoverflow.com/questions/6491532/how-to-subset-a-file-select-a-numbers-of-rows-or-columns