Different matrix sizes

[Lila14]

Am I correct in understanding that the two input matrices must be of the same size with the same genomic coordinate for every row? I think this is the reason for the following error:

Error in data.frame(vec_Rep1, vec_Rep2[, 3]) : 
  arguments imply differing number of rows: 38167684, 38130625
Calls: htrain -> prep -> data.frame

It would be useful if future versions could include support for matrices with different sizes or genomic coordinates. Thanks!