I will put it back your way for the next beta, as 3 : '(-(y -~ !)%0.001&* (0.001%~[:-/[:! 0.001 0 +/ ]) ])^:_<.&170^:(-:+)^.y'
Like all Newton's Method solutions, it goes bad if the derivative is too small. If you can make it more robust let me know.
Henry Rich On 9/4/2019 1:21 PM, Don Guinn wrote:
factinv=:3 : 0 d=: 1 : '0.001%~[:-/[:u 0.001 0+]' (-(!-y"_)%0.001&*!"0 d])^:_<.&170^:(-:+)^.y )
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