From mboxrd@z Thu Jan 1 00:00:00 1970 From: cym224 at gmail.com (Nemo) Date: Wed, 12 Feb 2020 16:55:57 -0500 Subject: [COFF] Fwd: Old and Tradition was [TUHS] V9 shell In-Reply-To: References: <20200212030152.GJ852@mcvoy.com> Message-ID: On 12/02/2020, Clem Cole wrote (in part): > But I suspect when he and his peeps were doing this with a > slide rule or at best an Friden mechanical adding machine, they were > acutely aware of how errors accumulated or not. This being COFF, I feel justified in chiming in with a story from my grad student days. A fellow student was working on something -- I have forgotten the actual problem but studying some behaviour near a singularity -- and he wanted some numerical values. So he obtained Fortran code from a grad student in physics. The result blew up in his region of interest. The person who gave him the code had no interest in investigating because he was happy with the results in his region. (After months of toil, he found serious approximation errors.) N.