Bug report split(string, delimiters) macro function

[Gabriel Schweighauser]

Dear List,

The built-in macro language function shows an unexpected behaviour if an
"empty" column is present in the string.

Example:

split("1,2,3,,5",",");

returns the same array as:

split("1,2,3,5",",");

Hence, parsing tables with "empty" cells from csv-files does not work.

Is there a way to fix this?

We're using ImageJ 1.49b.


Thanks for your reply,
Gabriel

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[Rainer M. Engel]

Am 23.07.2014 18:08, schrieb Gabriel Schweighauser:

> Dear List,
>
> The built-in macro language function shows an unexpected behaviour if an
> "empty" column is present in the string.
>
> Example:
>
> split("1,2,3,,5",",");
>
> returns the same array as:
>
> split("1,2,3,5",",");
>
> Hence, parsing tables with "empty" cells from csv-files does not work.
>
> Is there a way to fix this?
>
> We're using ImageJ 1.49b.
>
>
> Thanks for your reply,
> Gabriel
>

... [show rest of quote]

Hello Gabriel,

we came across this a few days ago. I don't think that it is a bug,
since this behaviour might be mandatory in other cases.

I wrote a macro function to fill empty fields for which the user has to
define a char he wants to fill with. This worked for my purposes.
https://dl.dropboxusercontent.com/u/414433/imagej/macros/function_fillEmptyFields.ijm

Does it work for you?

Best regards,
Rainer


--
Rainer M. Engel, Dipl. Digital Artist
scientific|Media GbR
Pichelsdorfer Str. 143
13595 Berlin

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[Michael Schmid]

Hi Gabriel,

the ImageJ 'split' (in ij.util.Tools) function uses the StringTokenizer, not the String.split function. Thus, multiple occurrences of the same delimiter are taken as one. Especially with whitespace characters as separators, this is usually the desired behavior.
I fear that changing this may break existing macros that rely on the current split function.

A way out would be having a second split function with a different name or a split function that behaves like String.split, but I don't know whether it's worth while.

A workaround might be adding spaces between the commas:

s="1,2,3,,5,,,8,,,,12,,,,,17";
s1=replace(replace(s,",,",", ,"),",,",", ,");
print(s1);
a=split(s1,",");
print(lengthOf(a));


Michael
________________________________________________________________
On Jul 23, 2014, at 18:08, Gabriel Schweighauser wrote:

> Dear List,
>
> The built-in macro language function shows an unexpected behaviour if an
> "empty" column is present in the string.
>
> Example:
>
> split("1,2,3,,5",",");
>
> returns the same array as:
>
> split("1,2,3,5",",");
>
> Hence, parsing tables with "empty" cells from csv-files does not work.
>
> Is there a way to fix this?
>
> We're using ImageJ 1.49b.
>
>
> Thanks for your reply,
> Gabriel
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html

... [show rest of quote]

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[Rasband, Wayne (NIH/NIMH) [E]]

On Jul 23, 2014, at 12:08 PM, Gabriel Schweighauser wrote:

> Dear List,
>
> The built-in macro language function shows an unexpected behaviour if an
> "empty" column is present in the string.
>
> Example:
>
> split("1,2,3,,5",",");
>
> returns the same array as:
>
> split("1,2,3,5",",");
>
> Hence, parsing tables with "empty" cells from csv-files does not work.
>
> Is there a way to fix this?

... [show rest of quote]

This bug is fixed in the latest ImageJ daily build (1.49e10).

-wayne

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