smoothRatio function

A function to smooth ratio values using cubic smoothing spline smoothRatio function splits values from 'ratio' column by chromosome and based the supplied 'groupMin' and 'split' parameters and then applies smooth.spline() function from R stats package. The supplied dataframe may contain multiple ratios, i.e. ratios produced using multiple replicating samples and/or multiple non-replicating samples. This must be reflected in 'name.rep' and 'name.nonRep' columns. In other words, different ratio dataframes may be merged using rbind() function before calling smoothRatio() function.