code: def MRA(biomf, sampleIDs=None, transform=None):
      
      ra = relative_abundance(biomf, sampleIDs)
      if transform is not None:
          ra = {sample: {otuID: transform(abd) for otuID, abd in ra[sample].items()}
                for sample in ra.keys()}
      otuIDs = biomf.ids(axis="observation")
      return mean_otu_pct_abundance(ra, otuIDs)
docs: Calculate the mean relative abundance percentage.
  
      :type biomf: A BIOM file.
      :param biomf: OTU table format.
  
      :type sampleIDs: list
      :param sampleIDs: A list of sample id's from BIOM format OTU table.
  
      :param transform: Mathematical function which is used to transform smax to another
                        format. By default, the function has been set to None.
  
      :rtype: dict
      :return: A dictionary keyed on OTUID's and their mean relative abundance for a given
               number of sampleIDs.