Paul McGuire wrote: >And I wouldn't necessarily agree with beliavsky's assertion that numarray >arrays are needed to represent payment dates and amounts, unless you were >going to implement a major banking financial system in Python.
Maybe arrays are not "needed", but especially for vectors of floating point numbers, I prefer to use a Numeric array rather than a list because (1) array operations like sum and exp are possible, and I want z = x + y to perform an element-wise sum rather than a concatenation of lists. Given arrays containing a set of times, coupon amounts, and interest rates, the value of a bond could be a calculated with a single expression, without loops. (2) A TypeError is raised if I do something illogical like x = zeros(3,Float) x[0] = "dog" (3) Higher-dimensional arrays are better represented with Numeric or Numarray arrays than with lists. -- http://mail.python.org/mailman/listinfo/python-list
