import_pulldown: Reads an input pulldown .csv file and organizes it for...
In dereksonderegger/PepSeq: Tools for analyzing Peptide Sequencing results

This function is intended to be how users import data from a pulldown.

import_pulldown(file, standardization_method = "additive",
  scale = TRUE, trim_proportion = 0.25, read_indicator = "X",
  protein_column = "protein_ID", position_column = "Peptide.start",
  Cleaved_Type_Indicators = c("Cl_", "Un_"))

`file`	The input .csv, .xls, or .xlsx file. It can be a full path to a file or a relative path from the current working directory.
`standardization_method`	The method by which the cleaved and uncleaved read counts are combined. Valid choices are 'additive' or 'multiplicative'. The default is additive.
`scale`	Should we rescale the signal result so that the maximum signal is between 100 and 1000.
`trim_proportion`	In the rescaling, what percent of the large values should be removed to get to a background rate.
`read_indicator`	An argument that identifies what columns are responses to be plotted. This could be either a vector of integers or a character string (or vector of strings) that is at the beginning of all of the column names of the response data.
`protein_column`	A character string indicating which column denotes the protein.
`position_column`	A character string indicating which column corresponds to the position within a protein.