repeat elements ('a','b') where 'a' has to repeat 157 times and 'b' has to repeat 173 times, sequentially?

157 values of 'a' then 173 values of 'b'

Answer 1

[Raj]

What is the exact issue here? Your 'tags' themselves are answers to your question. Use repelem and repmat to get what you want depending on whether a and b are matrices or elements.