Writing formulas to excel spreadsheet

W

Will James

Hi, everyone. I've just started using ruby a couple of days ago, and
I've been using it to read data from text files and write to excel
spreadsheets. I also need to be able to write formulas to spreadsheets,
but when I open the excel file, the formula is in there without having
been evaluated - for example, the cell will appear as "=A1+A58+A114"
instead of whatever the value of that sum happens to be. If I click on
the cell and hit "enter," the formula will evaluate, but it does not do
so automatically.

Is there any way to get ruby to force excel to evaluate? Thanks!
 
M

Mike Stephens

Have a look at :rubyonwindows.blogspot.com/search/label/excel

and look for 'formula'
 
7

7stud --

Mike Stephens wrote in post #999754:
Have a look at :rubyonwindows.blogspot.com/search/label/excel

and look for 'formula'

...which shows this:

Adding Formulae

emptyRow = 15
worksheet.Range("t#{emptyRow}")['Formula'] =
"=(Q#{emptyRow}+L#{emptyRow}+I#{emptyRow}+S#{emptyRow})"
 
W

Will James

7stud -- wrote in post #999761:
Mike Stephens wrote in post #999754:
Have a look at :rubyonwindows.blogspot.com/search/label/excel

and look for 'formula'

...which shows this:

Adding Formulae

emptyRow = 15
worksheet.Range("t#{emptyRow}")['Formula'] =
"=(Q#{emptyRow}+L#{emptyRow}+I#{emptyRow}+S#{emptyRow})"

Thanks, guys. However, the above seems to require win32ole, for which,
if I'm not mistaken, you need office to be installed on the system.

Is there a way to do this with just the spreadsheet gem (i.e. just
require spreadsheet)?
 
C

Chuck Remes

7stud -- wrote in post #999761:
Mike Stephens wrote in post #999754:
Have a look at :rubyonwindows.blogspot.com/search/label/excel

and look for 'formula'

...which shows this:

Adding Formulae

emptyRow = 15
worksheet.Range("t#{emptyRow}")['Formula'] =
"=(Q#{emptyRow}+L#{emptyRow}+I#{emptyRow}+S#{emptyRow})"

Thanks, guys. However, the above seems to require win32ole, for which,
if I'm not mistaken, you need office to be installed on the system.
Is there a way to do this with just the spreadsheet gem (i.e. just
require spreadsheet)?

I looked through the code in the spreadsheet gem a few months ago (2?) looking for this functionality. As far as I could tell, it was not yet possible to *write* formulas to a spreadsheet cell. It looks like that functionality is on the roadmap. Look at the "roadmap" section on the homepage: http://spreadsheet.rubyforge.org/

Looks like formula support isn't slated until version 0.8.0 (and we're on 0.6.x right now).

cr
 
M

Mike Stephens

Will James wrote in post #999789:
the above seems to require win32ole, for which,
if I'm not mistaken, you need office to be installed on the system.

I'm intrigued - how are you running Excel to get it to calculate
formulae if it's not on your computer?

As it happens, I don't think win32ole has got anything to do with Office
anyway. It's to do with OLE, which is a Windows feature. Excel happens
to present an OLE object model.
 
W

Will James

Mike Stephens wrote in post #999926:
Will James wrote in post #999789:

I'm intrigued - how are you running Excel to get it to calculate
formulae if it's not on your computer?

As it happens, I don't think win32ole has got anything to do with Office
anyway. It's to do with OLE, which is a Windows feature. Excel happens
to present an OLE object model.

There are alternatives to office (i.e. openoffice) which allow you to
work with excel spreadsheets but don't provide the necessary COM objects
or whatever it is that's needed to use some features of certain
libraries or modules in certain languages. I think to do:

class ExcelConst
end
WIN32OLE.const_load(excel, ExcelConst)

or

excel = WIN32OLE::new('excel.Application')

you do need to have excel installed. I remember in perl, to do stuff
like:

use Win32::OLE qw(in with);
use Win32::OLE::Const 'Microsoft Excel';

you need to have excel on the system. I'm not a professional programmer
(these days, I mostly program to automate a lot of painful data
crunching tasks that would take ages to do by hand), so some of this is
a bit beyond me...

Chuck - thanks. It's too bad that the formula stuff isn't implemented
yet, but could there be some clever workarounds to force or trick excel
into evaluating?
 
M

Mike Stephens

Will

I'm still fascinated why you are doing sophisticated things with Excel
(not Open Office) but steadfastly refuse to load it on your computer.
Windows and Excel can be purchased for the price of a monitor. You gain
ownership of software that costs hundreds and hundreds of millions to
develop.

Why fanny around with some Micky Mouse spreadsheet gem when you can have
the Full Monty?
 
D

Daniel Berger

Will

I'm still fascinated why you are doing sophisticated things with Excel
(not Open Office) but steadfastly refuse to load it on your computer.
Windows and Excel can be purchased for the price of a monitor. You gain
ownership of software that costs hundreds and hundreds of millions to
develop.

Why fanny around with some Micky Mouse spreadsheet gem when you can have
the Full Monty?

Even if he had it installed locally, I'm guessing that he would want
to generate the document in code since generating it by hand would be
cumbersome. In addition, the spreadsheet gem works on any platform
(last I checked).

Regards,

Dan
 
W

Will James

Daniel Berger wrote in post #999984:
Even if he had it installed locally, I'm guessing that he would want
to generate the document in code since generating it by hand would be
cumbersome. In addition, the spreadsheet gem works on any platform
(last I checked).

Regards,

Dan

Yep, that's correct - I want the scripts to work across a variety of
platforms, with as little dependence on outside applications and
libraries as possible. This is partly because the scripts I'm writing
may be used by a few others; I don't know about what software they will
or won't have on their systems, and they will likely not be too willing
to resolve too many dependency issues. I do have office installed on one
of my systems, but don't have access to that one right now, and will not
buy another copy just for this task.

The spreadsheet gem meets the above requirements, and it was working
brilliantly until I got to writing formulas to spreadsheets.
 
M

Mike Stephens

Chad Perrin wrote in post #1000098:
and frankly, you shouldn't have to explain why you're writing code
for something like this, unless it's actually relevant to the problem
you want help solving.

Chad, if you ever want to learn anything,and my experience of you -like
others before me - is you don't, learn this: it is always vital to
understand why you are doing something.
 
D

Damjan Rems

Just my 5 cents. What do you need formulas for. Is your data going to be
changed by hand in the future?

If not, why not calculate it by your program.

by
TheR
 
M

Mike Stephens

Chad Perrin wrote in post #1000266:
but it is *not* vital to explain to some
Microsoft obsessed shitbird why you are using Ruby to interact with an
XLS file rather than doing it "by hand" in Excel.

The trouble with you Chad is you always manage to miss the point.

No-one on this thread has mentioned doing it by hand. The issue was
whether or not to use Windows OLE rather than a Linux environment, given
that the end-product is for Windows users, and that it is does what Will
wants - unlike his Linux solution.

I'm not Microsoft obsessed. The simple fact is it is the Linga Franca of
the computing world. Linux is only on a tiny minority of desktops. So
it's natural to question why someone would choose to go down a such a
route when Windows is what most other people would be using.

Will has said his colleagues just happen to be avid Linux fans so that's
fair enough.
That answers the question.

I know on this channel I will get the anti-Microsoft lobby. Fortunately
I don't get it at work. Professional programmers grudgingly accept that
NET has bugs and the usual MS baggage but probably is a better bet than
say Java for mainstream e-business. Sadly people rarely have an opinion
on Ruby.
 
M

Michal Suchanek

Chad Perrin wrote in post #1000266:

The trouble with you Chad is you always manage to miss the point.

You too.
No-one on this thread has mentioned doing it by hand. The issue was
whether or not to use Windows OLE rather than a Linux environment, given
that the end-product is for Windows users, and that it is does what Will
wants =C2=A0- unlike his Linux solution.

Not necessarily, the spreadsheets can be used on a variety of systems
all of which can read them.
Now I would choose a different file format but if part of the target
users want to open the files in Excel or another spreadsheet this
might be the most suitable format for the purpose.
CSV or HTML works too but importing into a spreadsheet is somewhat problema=
tic.
I'm not Microsoft obsessed. The simple fact is it is the Linga Franca of
the computing world. Linux is only on a tiny minority of desktops. So

Maybe where you work. I would guesstimate Windows being on about half
of computers in the world.
That's something that should be taken into consideration but not taken
for granted.
it's natural to question why someone would choose to go down a such a
route when Windows is what most other people would be using.

Will has said his colleagues just happen to be avid Linux fans so that's
fair enough.
That answers the question.

I did not see anything about them being avid Linux fans. If you did
not notice there are things like Windows without MS Office installed,
OS X, even PDAs and tablets that can run Ruby but not MS Office OLE.
I know on this channel I will get the anti-Microsoft lobby. Fortunately
I don't get it at work. Professional programmers grudgingly accept that
.NET has bugs and the usual MS baggage but probably is a better bet than
say Java for mainstream e-business. Sadly people rarely have an opinion
on Ruby.

I don't know what you mean by e-business. If you mean serving web
pages then I would rather rely on Java then .NET for the purpose.

Regards

Michal
 
C

Christopher Dicely

I know on this channel I will get the anti-Microsoft lobby. Fortunately
I don't get it at work. Professional programmers grudgingly accept that
.NET has bugs and the usual MS baggage but probably is a better bet than
say Java for mainstream e-business.

Well, except that plenty of professional programmers come to the exact
opposite conclusion wrt the relative desirability of .NET and Java for
mainstream e-business.
 
W

Will James

Damjan Rems wrote in post #1000470:
Just my 5 cents. What do you need formulas for. Is your data going to be
changed by hand in the future?

If not, why not calculate it by your program.

by
TheR

I thought about doing it this way, but the spreadsheet will have
calculations based on previous calculations, based on previous
calculations, and so on, so it's good to have the formulas in there, in
part so that whoever is viewing the formulas can follow the process of
how something is derived (without too much effort), and so that the
viewer can verify that nothing went wrong anywhere in the process of
deriving the final values. Basically, the formulas are good for
transparency, in this case.
 
M

Mike Stephens

Michal Suchanek wrote in post #1000501:
I would guesstimate Windows being on about half
of computers in the world.
even PDAs and tablets that can run Ruby but not MS Office OLE.

According to this
http://marketshare.hitslink.com/operating-system-market-share.aspx?qprid=10

90% of computers run Windows, so normally you'd stand a fair chance of
your program working if you used OLE.
I don't know what you mean by e-business. If you mean serving web
pages then I would rather rely on Java then .NET for the purpose.

I'm not saying I'm right or that MS is better. I'm just saying there are
a lot of people in my world (eg web apps for customers to service
120,000 loans; websites to sell international health insurance etc) and
they just don't have this slightly puerile anti-microsoft attitude, so
I'm confused why a few people on here cannot help themselves from making
snide remarks whenever MS is mentioned.
 
J

Johnny Morrice

I'm not saying I'm right or that MS is better. I'm just saying there
are a lot of people in my world (eg web apps for customers to service
120,000 loans; websites to sell international health insurance etc)
and they just don't have this slightly puerile anti-microsoft
attitude, so I'm confused why a few people on here cannot help
themselves from making snide remarks whenever MS is mentioned.

Before my unbelieving eyes, you have transformed a discussion on using
ruby into an operating system flame war. Now that's magic!

Do you do parties?
 
S

Stu

x11 is not an operating system. FreeBSD is not even on that list. If
your gonna link analysis and statistic web at least link one that has
been around since before the bubble.

http://news.netcraft.com/archives/2...e-hosting-company-sites-in-december-2010.html

As for referring to your peers as childish within your remark about M$
hate. Seriously if you don't know what the problem is at this point
you really should reevaluate some of this cognitive dissonance so you
wont be spewing bullshit like over 90% computer in the whole world run
x,y,z OS.
 
C

Colin Bartlett

Daniel Berger wrote in post #999984:

Yep, that's correct - I want the scripts to work across a variety of
platforms, with as little dependence on outside applications and
libraries as possible. This is partly because the scripts I'm writing
may be used by a few others; I don't know about what software they will
or won't have on their systems, and they will likely not be too willing
to resolve too many dependency issues. I do have office installed on one
of my systems, but don't have access to that one right now, and will not
buy another copy just for this task.

There are other use cases for what you want to do, which is why I'm
interested in any problems you come across and any ways you solve
them. For example: I distrust spreadsheets for making important
calculations (too easy to make errors in obscure cells without
noticing), but they are very useful for displaying data. So I make
some calculations using Ruby (or whatever), and then display the
results on a worksheet page, using formulas to generate some of the
displayed results for the same reasons you give in a later post "it's
good to have the formulas in there, in part so that whoever is viewing
the formulas can follow the process of
how something is derived (without too much effort)". An important part
of what I'm doing is that the worksheets will be usable in even quite
old versions of Excel, so I only want to use elementary features of
Excel.

Actually, the original version of this used Microsoft Excel
VisualBasic for Applications, with all the calculations being done in
VBA, and using VBA to generate the worksheet pages. But I'd rather use
Ruby for the calculations, so I'm currently rewriting it, hence my
interest in what you're doing.

I'm assuming you've looked at things like this
http://www.cpearson.com/excel/optimize.htm
which has a section on using VBA to force calculations: I haven't
tried adapting the VBA code to run from Ruby accessing Excel, but it
should be possible?

As a very orthogonal suggestion: one thing that was worrying me about
my approach was what if I couldn't manage to get Ruby to write
anything directly into Excel. (You haven't got that problem.) But a
possible solution occurred to me: use Ruby (or whatever) to generate a
text file which has a list of cells and values or formulas (and
formatting) to be entered into (or used by) each cell. Then write a
VBA function to read such text files and generate the worksheet(s): a
little messy, but fairly easy to do, and I was much happier once I had
a backup plan if directly accessing Excel through Ruby didn't work.
 

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