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I have a list of around 100 matrices, that looks like this

A={{{425060., 2.14235*10^6, 0.49, 0.01, 0.38, 0.620161, 
   20.}, {1.24808*10^6, 1.53025*10^6, 0.04, 0.07, 0.31, 0.320312, 
   20.}, {7.39304*10^6, 1.40204*10^6, 0.83, 0.45, 0.09, 0.94842, 20.} .... {4.27537*10^6, 
 1.62124*10^6, 0.24, 0.28, 0.62, 0.721388, 20.1}, {3.27776*10^6, 
 2.25816*10^6, 0.01, 0.21, 0.72, 0.750067, 20.1}, {3.0814*10^6, 
 1.95624*10^6, 0.02, 0.19, 0.72, 0.744916, 20.1}, {2.42706*10^6, 
 1.25729*10^6, 0.03, 0.17, 0.7, 0.720972, 20.1}, {4.47196*10^6, 
 1.23247*10^6, 0.24, 0.27, 0.57, 0.674833, 20.1}, {1.57132*10^7, 
 1.65019*10^6, 0.76, 0.92, 0.5, 1.29383, 20.1} ...... 

Each matrix has an unknown number of rows. I want to make a frequency histogram, where the frequency is the number of rows in a matrix and the bin value is the last element of each row. So eg: the first matrix has 50 rows, and the last element of each row is 20.0, so the frequency is 50 for the value 20, and so on.

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  • $\begingroup$ Why not Histogram[Last /@ A]? $\endgroup$ – kglr Oct 31 '14 at 8:04
  • $\begingroup$ I tried that, but it doesn't seem to work for a list of matrices. $\endgroup$ – HuShu Oct 31 '14 at 18:11
  • $\begingroup$ For a list of matrices Histogram[A[[All, All, -1]]] should work. $\endgroup$ – kglr Oct 31 '14 at 18:47
  • $\begingroup$ That works! thank you. :) $\endgroup$ – HuShu Oct 31 '14 at 20:29
  • $\begingroup$ Nilanjan, great... just posted the comment as an answer. $\endgroup$ – kglr Oct 31 '14 at 20:38
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Perhaps

Histogram[A[[All, All, -1]]]
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