Another deficiency I've noticed in my above solution is that it does not
converge for complex eigenvalues.
- Rowan
On Mon, Apr 13, 2020 at 6:07 PM Rowan Cannaday <cannad...@gmail.com> wrote:
> Here is a quick solution to the eigenvalue problem. Should be refined and
> extended to calculate eigenvectors.
>
> {0~⍨∈⍵×∘.=⍨⍳≢⍵}({r+.×⍉qt⊣(qt r)←⌹[⎕CT]⍵ ;qt;r}⍣{(|⍺)≡|⍵}) 3 3 ⍴ ⍳9
> 16.11684397 ¯1.11684397 ¯3.625973215E¯16
>
> As a quick note, my ⎕CT was 1E¯13, however it doesn't seem to zero out the
> ¯3.625973215E¯16. I suspect this is due to it being a negative number. Its
> not that big of a hurdle, it can be easily worked around with an extra
> function. Worlframalpha for example rounds it to 0 in their solution.
>
> Many thanks,
>
> - Rowan
>
> On Mon, Apr 13, 2020 at 5:30 PM Peter Teeson <peter.tee...@me.com> wrote:
>
>> The paper you referred to was a huge epiphany for me.
>> Having previously worked in the business world using COBOL and FORTRAN
>> the beauty and elegance of APL blew me away. It still does.
>>
>> At IPSA we used to model proposed changes (mostly algorithms) to the
>> interpreter in APL first.
>> And then wrote the Assembly code to implement.
>>
>> On Apr 13, 2020, at 11:48 AM, Dr. Jürgen Sauermann <mail@xn--
>> jrgen-sauermann-zvb.de> wrote:
>>
>> That was my point. If we could establish APL as a language for describing
>> algorithms. I was thinking
>> along the lines of Iverson's "Notation as a tool of thought" which is
>> also free now:
>>
>> https://dl.acm.org/doi/10.1145/358896.358899
>>
>>
>>
