Financial models using Ruby

Ruby
1

I’m working on this financial
modelhttp://leeds-faculty.colorado.edu/moyes/html/documents/FinancialProjectionsModelv6.8.9.xlsfor
my upcoming ecommerce business using OpenOffice.org Calc (and the
BASIC
programming language). But as the need for more advanced programming
arises
(making the various spreadsheets more dynamic and interconnected,
applying
algorithms for analyzing data and forecasts etc.) I can’t help but think
that maybe this would all be a lot easier if it was Ruby.

Is anyone aware of similar financial models made using Ruby, and if so
how
are they implemented? Are they simply Ruby wrappers for Calc or Excel,
or
maybe Xero, or a dedicated Rails app?

–Dwayne

2

On 02/05/2013 08:41 AM, Dwayne H. wrote:

–Dwayne
Hi Dwayne!
I’m not familiar with any financial models, but I’ve seen a lot excel
stuff for analyzing data. so here are my
2cts:

When I worked for a x-Ray tube company, they used excel to prepare data
for the tube controller. I took 1-2
hours for every tube and only 2 people were able to do this. My first
task was to improve this situation. I
used ruby for this, although they wanted me to do this in VBA :wink:

With my final version it was possible to create the data

  1. within 5 min per tube
  2. automatically from the command line
  3. independent of the number of data sets (excel strongly depends on the
    number of rows or columns of input data).

The drawbacks:

  1. people could not longer use Excel - I’m not kidding, this IS a real
    disadvantage, because (esp.)
    non-programmers tend to use excel for everything. That’s why it’s a lot
    easier to give your software away,
    when you’ve written it in Excel (or calc). People are simply familiar
    with it.
  2. no gui - my gui was an editor with the config file opened. Anything
    else (like a cool gui) will keep you
    from the problem (or I am just not familiar with writing guis).

I think ruby is a really good choice for doing these things -
implementation could take a while, but you’ll
get a lot back: Most important might be Unit-testing (I’m sure there are
thousands of buggy excel lists in the
banks out there - hey might be the REAL reason for the crisis ;-).
As long as you do not want to change anything excel is ok, because it
simply runs. Keep in mind, who should
use your software - programs are most useful when used properly.

regards
ralf

3

Hey thanks a lot Ralf - tons of strong points there. I’ll definitely be
going for Ruby now.

The drawbacks:

  1. people could not longer use Excel
  2. no gui

I’m sure I can make up for this by turning it into a smooth Rails webapp
(that imitates cells), maybe coupled with a decent charting library. If
anybody has any suggestions, do feel free to let me know and in turn
I’ll
keep them posted as well.

Most important might be Unit-testing (I’m sure there are thousands of
buggy excel lists in the banks out there - hey might be the REAL reason
for
the crisis ;-).

Hahaha :slight_smile:

Thanks again man!

4

There are ways to build a GUI using gems, or link excel and a ruby
program in such a way that excel itself acts as your GUI.

I do a fair bit of work with both Excel VBA and Ruby, and the tool I
choose depends on the task.

Generally, if the calculations are simple, and done direct from excel
into excel, then VBA does the job.

If you have something complex that needs doing, then you can save
yourself a lot of headache by writing it out in concise Ruby code.
This is ideal when you know the users have the framework installed, when
you can use RoR, or when “.exe” builds are suitable.

One option is to use Ruby and Excel side-by-side, as each can trigger
the other.