I have a little beginners problem I suppose. When using the histogram plot function the output data are translated to have min value = 0. Apart from that the plot seems to be correct (i.e. the densityfunction looks like it should). When plotting several histograms in the same plot all curves are starting from zero. There is not att data problem, since when lettting IDL compute the min value of the set it is !=0. Have anyone seen this before and/or have the (I suppose it is) simple solution to my problem. Regards