# Forecast(), set\_history() or set\_output\_multiple()

**URL:** <https://www.ruby-forum.com/t/forecast-set-history-or-set-output-multiple/240545>\
**Category:** GNU Radio\
**Created:** [April 19, 2014, 8:50pm UTC](https://www.ruby-forum.com/t/forecast-set-history-or-set-output-multiple/240545 "2014-04-19T20:50:38Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Detlef\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/58f4c7/32.png) [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\
**Post date:** [April 19, 2014, 8:50pm UTC](https://www.ruby-forum.com/t/forecast-set-history-or-set-output-multiple/240545/1 "2014-04-19T20:50:38Z")

</div>

Hi everybody,

I’m working on building a block which processes samples in chunks: if  
the energy of each chunk is greater than a given threshold, the chunk is  
reported in output. Moreover for each chunk reported in output, the N  
preceding chunks should be reported in output as well.

How can I manage this last requirement? Which is the best function to be  
used for this purpose( forecast(), set\_history(), set\_output\_multiple()  
or others) and how can I set it?

Thanks in advance.