Re: Applying a function to selected element type in a mixed-type cell array

[Philip Nienhuis]

Ben Abbott wrote:
> On May 21, 2012, at 5:43 PM, Philip Nienhuis wrote:
>
> > Suppose a cell array like:
> >
> > arr = {10, int32(15), 'Txt'; '', 25, true; NaN, 'String', single(100)}
> >
> > How can all numeric values efficiently (w/o for loops etc.) be converted to 
> > double, leaving the other cell array contents untouched?
> >
> > Getting at something like  "arr(find (cellfun ("isnumeric", [arr])))" is easy 
> > enough, but the follow-up is a hazy to me.
> >
> > Thanks,
> >
> > Philip
>
> A Two-liner ?
>
>         n = cellfun (@isnumeric, arr, "UniformOutput", true);
>         arr(n) = cellfun (@double, arr(n), "UniformOutput", false);

Yep that'll work fast enough. I got close to something like the second 
line myself but I guess I forgot about the '"UniformOutput", false' thing.

BTW I need this to fix a bug in the io pkg spreadsheet writing scripts 
that turns out to have been there from the very beginning:
The various Java and ActiveX methods that transfer numerical values to 
spreadsheets accept only doubles, no int<x>, single or unsigned.
Not so strange when you realize that spreadsheets essentially contain 
just boolean, double or text values (cell formatting makes for a 
-cosmetic- wider variety). I never hit this limitation until today at 
work when I was converting text files containing integer values into 
spreadsheets.

Thanks Ben & Juan,

Philip