I'll leave the rest until you've had a chance to finish fleshing out your
current position but just wanted to get some further clarification on your
point 4).
> From: Don Watson
> ...
> However a few clarifications follow:
> 4) I want to use only primitives and not previously defined verbs
> (subroutines), because that is how mathematical formulae are defined -
> however, other people should be free to use subroutines, programs and
> control structures as they wish.
Now that you/your student has defined the verb stddev, are they able to reuse
it as part of any other equation?
How about the following mathematical formula to calculate the correlation
between x and y:
sigma(x,y)
Corr(x,y) = ____________________
sigma(x) sigma(y)
Are they allowed to define a verb to provide the covariance of x & y and then
code the correlation like this? :
(x cov y) % (stddev x) * (stddev y)
If "yes" then surely those verbs can be described as "subroutines" (appears
they occur in mathematical formulae too!)? If "no" then I would disagree that
the approach fosters understanding of the subject.
Here is a definition of cov in case you want one.
cov=: dyad def '(<:#x) %~ +/ (x - mean x) * (y - mean y)'
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