Dear list,
Histograms are usually used to check the quality of microarray 
experiments. If there are bi-modalities in a particular array, it is a 
candidate to exclude it from the experiment. It is easy to check 
bi-modalities or multi-modalities visually, but I would like to know if 
there is a way (using a statistical test or something) to check 
multi-modalities using the data returned by the hist function.

For an Affybatch object, hist function returns the X and Y values, but 
that's all, it doesn't return the variables breaks, counts, etc as it is 
said in the help manual for hist. So, I have two questions:

    * Is there a test to check for multi-modalities in histograms?
    * Is there a way to know the cells and the number of values per cell
      used by hist to check for multi-modalities in a rudimentary way?

Thanks again,
Javier


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