Argument error in ludcmp when using Newton module

Ruby
1

Hi,

I am trying to use bigdecimal/newton for an implementation of XIRR. A
copy of the code I am trying to run can be found here:
http://pastebin.com/VVMB4bRs

When I run the code (Ruby 1.9.2 on Mac OS X 10.6), I get the following
error:

/opt/local/lib/ruby1.9/1.9.1/bigdecimal/ludcmp.rb:84:in div': wrong number of arguments(2 for 1) (ArgumentError) from /opt/local/lib/ruby1.9/1.9.1/bigdecimal/ludcmp.rb:84:in block in
lusolve’
from /opt/local/lib/ruby1.9/1.9.1/bigdecimal/ludcmp.rb:78:in downto' from /opt/local/lib/ruby1.9/1.9.1/bigdecimal/ludcmp.rb:78:in lusolve’
from /opt/local/lib/ruby1.9/1.9.1/bigdecimal/newton.rb:60:in nlsolve' from gistfile1.rb:52:in ’

Is this because of an error in my program, or something in the
BigDecimal library?

Any assistance in debugging this would be greatly appreciated.

Thanks,
Bill

2

Hi Bill,

You got the error because your Function#values returned a Float
instead of a BigDecimal.
While BigDecimal#div can take up to two arguments, Float#div takes only
one.
Here is a modified version of your code: http://pastebin.com/C9ratXer
Hope this helps.

Tomo