Mailing-List: contact dev-help@poi.apache.org; run by ezmlm
Precedence: bulk
Reply-To: "POI Developers List" <dev@poi.apache.org>
MIME-Version: 1.0
Message-ID: <pony-a2404be515bfb17799c455c18c0debfdcda1e6db-fd1a1ed0aedff3582363382dc4a5944975f98401@dev.poi.apache.org>
Subject: Re: Table Formula Manipulation and Matrix Function Implementation in HSSF/XSSF
References: <CAEwphwqdao1BTeSS4wrjVKwDzMPq52EMmGs4sQF6Ae3692RS=w@mail.gmail.com> <SN1PR09MB1039C8EFDECC8E5F8147F36AEADC0@SN1PR09MB1039.namprd09.prod.outlook.com>
From: "Robert Hulbert"<bob951321@gmail.com>
In-Reply-To: <CAEwphwqdao1BTeSS4wrjVKwDzMPq52EMmGs4sQF6Ae3692RS=w@mail.gmail.com>
Content-Type: text/plain; charset="iso-8859-1"
Date: Wed, 28 Jun 2017 22:35:40 -0000
To: <dev@poi.apache.org>
archived-at: Wed, 28 Jun 2017 22:35:45 -0000

Correction, I meant to say array formulas. For example, when I attempted testing component binary operations (+,-,*,/) using array formulas (formula over an area w/ CTRL+SHIFT+ENTER), it evaluated to [!VALUE] in the cell where the formula was and empty string in subsequent cells.

On 2017-06-27 15:59 (-0700), Greg Woolsey <greg.woolsey@gmail.com> wrote: 
> I implemented the current table formula handling, based on a patch I found
> languishing in the bug database.  It's been a year or so, but here's what I
> remember:
> 
> Data Table syntax works in most cases, but there is definitely room for
> more test cases looking for bugs in less common scenarios - Unicode in
> table header names, characters requiring quoting, references to the current
> or external workbooks are some I can think of off the top.
> 
> There are exceptions and JavaDoc notes in many places stating array
> formulas are not supported, and some open bugs about functions that work
> only partially or incorrectly because of incomplete array formula support.
> For example you can set array formulas for a sheet, but POI doesn't
> evaluate them when calculating.
> 
> I don't think there is much support at all currently for anything matrix
> related.  Parsing array syntax will be a tricky challenge, but if done
> would likely allow a good portion of array/matrix function implementations
> without much further fuss.
> 
> Table formula syntax is not allowed by Excel in places like chart
> definitions.  If someone wanted to work on functionality similar to that in
> Excel that can attempt to infer table/chart relationships, and thus offer
> some support for automatically adjusting chart definitions based on table
> additions/deletions, that would be an amazingly helpful feature to many
> users, I suspect (and myself for sure! :)  )
> 
> Somewhere on one of the mailing lists was a good collection of links to
> pages and videos related to implementing functions in POI, but I'm failing
> to find them right now.
> 
> On Tue, Jun 27, 2017 at 1:01 PM Hulbert, Robert Douglas <hulbert2@llnl.gov>
> wrote:
> 
> > Hi,
> >
> > I'm a summer student at Lawrence Livermore National Laboratory and was
> > hired to find or implement POI's table formulas and matrix functions.
> >
> > Over the last week or so, I have checked the POI page/Contributor
> > guidelines and have looked through the source code for handling this
> > functionality.
> >
> > Is anyone still interested in this functionality? If not, is there any
> > documentation on where this aspect left off?
> >
> > Thank you so much for any help you can give!
> >
> > Best Regards,
> > Robert Hulbert
> >
> 

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@poi.apache.org
For additional commands, e-mail: dev-help@poi.apache.org