added class to implement unionfind data structure
added code to find connected components in binary image
cluster finding refactored into function
added docstring for label_clusters
moved label_clusters to physutils
added fn to get cluster sizes
removed cluster sizes code to physutils
switched connected components scratch over to ipython notebook
changed time_frequency_scratch over to ipython notebook
refactored avg_time_frequency to use helper function per_event_time_frequency
added code to demonstrate contrast plot between conditions
fixed bug in label_clusters whereby last cluster cut off
added helper functions to produce contrast plots, thresholded difference images
added code to do bootstrap and plot result
have notebook version of code working to plot only significant clusters
more refactoring of avg_time_frequency to extract a helper function
notebook now has code to properly mask and plot significant regions
added code to convert labels to array in make_threshold_diff
notebook now working
added functions to select and threshold clusters in image