Module correlate_to_reference_file

Determine the correlation between ct-level real properties from one
file to a reference.  CT's are matched by their titles. 
options
file_name {string} - Path to the file to check, readble by structurereader
file_property {string} - Name of the ct-level property in the file_name
    to use.  This should start with r_ or i_
ref_file_name {string} Path to the reference file, 
    readble by structurereader
ref_file_property {string} - Name of the ct-level property in ref_file_name
    to use.  This should start with a r_ or i_
min_correl {float} Correlation (R, not R-squared) should be less than 
    this value if this is a negative value (more negative correlation) 
    and more than this value if this is a positive value (more positive 
    correlation)