Hi!

* Tobias Peters; 2003-11-28, 14:19 UTC:
[Given that first three years Matz did Ruby development all alone
then with the help of others, presently nearly 40 people. How many
man years of development did go into Ruby?]

> Then of course it's 3 + (40 + 1) * 0.5 * (10 - 3) = 146.5 man years.

Let me see if I correctly understand that formula. In the first three
years Matz did work all alone. This gives 3 * 1 = 3 man years.

In the remaining time - this is the factor (10 - 3) the number of
contributors did raise linearly from 1 to 40 which means an average
number of contributors of (40 + 1) / 2.

Let's see what we get if we assume an exponential growth. The number
then grew from 1=0^log7(40) to 40=7^log7(40).

3 + int(0,7,x^{log7 40},dx) = 100 (actually 99.69...)

Besides that theoretical issue there is also a practical one: A
contribution may be tiny or huge. So the effective number of the
present number of contributors may range from 1 + epsilon to 1 + 40.
Without doing actual measurements the numbers computed are just
numbers but do not provide any insight.

Josef 'Jupp' Schugt
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