I have a 1x1 structure which has 1x3 fields which further has 1x5 runs. Each run has different double data(same no. of columns, different no. rows). I want to concatenate it like run 1 its data 203x7 double, run 2 its data 216x7 double and so on. Also assign Column names to each 7 columns. How to do that within a loop?