Help with rowfun?

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amen45 2017-2-21

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评论： Rik 2017-2-24

I've created a table with columns Go,Export, and Directory and row names from a list of strings (ex {'First Row','Second Row'})

I have a helper function, generic_helper that takes each of a Go, Export, and Directory values from a table, along with the string corresponding to the row (ex 'First Row') and a binary flag that does not change across rows.

How can I apply rowfun to call generic_helper(Go,Export,Directory,rowName,ex_bin_flag) for the values of Go,Export,Directory, and rowName in each row of my table?

Thanks in advance!

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Rik 2017-2-21

Have you considered a for-loop? If so, why doesn't that do what you need?

amen45 2017-2-21

I have one now, but as I understand with tables in matlab vectorizing is particularly advantageous in terms of speed (unlike say cellfun for cell arrays). if I'm mistaken, I'd love an explanation!

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Rik 2017-2-22

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You should have the helper function with some output (one or multiple scalars (single values)). Then, in your code you can use

newtable=rowfun(@generic_helper,table);

Note from rowfunc doc: "To return more than one output from func, use the 'NumOutputs' or 'OutputVariableNames' name-value pair arguments."

PS you were correct in looking for a vectorized solution, they are indeed generally faster. For smaller problems the effect is often negligible, but it always affects readability.

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amen45 2017-2-24

sorry, should have been more specific. they are globals that are passed to the generic helper function, as shown in my example code above. This is all happening in a larger module.

Rik 2017-2-24

Well, then you can either declare bin_flag and rowName as global variables, or create two new global variables in which you paste the content of bin_flag and rowName.

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