[ Date Index ] [ Thread Index ] [ <= Previous by date / thread ] [ Next by date / thread => ]
> On 26 Mar 2023, at 11:07, Tom via list <list@xxxxxxxxxxxxx> wrote: > > On 07/03/2023 09:43, rich_met wrote: >> Hi there >> I should be showing up as "rich_met" and I'm down West Cornwall. >> >> I realised I've been "ploughing a lone furrow" for far too long so >> reaching out to the group. >> 20 years ago was in Cambridge and member of Linux User Group there. >> In meantime, not been member of any club or group association with any >> computing. >> >> Where am I at now... >> >> I code mostly in emacs-lisp so it's right there in the emacs >> text-processor. >> >> eg. "topmost" "user-level" program for doing (Euler-Bernoulli) beam >> looks like this >> >> (defun beam-fmax-rhs-simple-cload >> (shs-width >> shs-depth >> shs-thk >> shs-length >> shs-stl-sigmamax ;; typically yield stress >> ) >> "for an RHS - max.force it will bear in central load simple beam >> best if all dimensions & values in SI / metres, etc >> Order of args matches order going into ma2nd calc / fn" >> (simple-support-dblbeam-loadcap >> (beam-moment-capacity >> shs-stl-sigmamax >> (beam-sect-mod-z-d >> (ma2nd-rhs-b-h-t shs-width shs-depth shs-thk) >> shs-depth)) >> shs-length)) >> >> so you can see at a glance I go >> >> 2nd moment of area (purely geometric property) >> v >> section modulus (purely geometric property) >> v >> beam moment capacity (combine geometry and material property) >> v >> "simple" centrally loaded beam capacity (given length, force it will bear) >> >> which is the normal progression of a beam calculation. >> >> An example of "real world" design I made and got used is here >> http://www.weldsmith.co.uk/tech/struct/210314_ebbeam_drillplat/19_drillplat_calcs.html >> >> "Cantilever drilling platform - analysis using beam calculations" >> >> >> I also do Finite Element Analysis modelling for stresses and strains - >> simply use an integrated software package for doing that. >> eg. >> http://www.weldsmith.co.uk/tech/struct/210216_bcfwtt_fea3d/210216_bcfwtt_fea3d.html >> >> "FEA3D : BCFWTT RHS beam top surface around test weld" >> >> "BCFWTT" is this physical "real world" test >> http://www.weldsmith.co.uk/tech/struct/210122_fwtest_rig/210122_fwtest_testrig.html >> >> >> >> Recently I did this which converts decimal GPS coordinates - >> eg. Google Maps >> to "human-usable" / "nautical chart" Degrees Minutes and Seconds >> >> entire code: >> >> (defun lat-long-degdeci-to-dms (latdeci longdeci) >> (format "%s %s %s" >> (abs-degdeci-to-abs-deg-min-sec (abs latdeci) (if (minusp latdeci) 'S 'N)) >> " " ;; easy jdi customisable way to separate lat. and long. output >> (abs-degdeci-to-abs-deg-min-sec (abs longdeci) (if (minusp longdeci) 'W 'E)))) >> >> (defun abs-degdeci-to-abs-deg-min-sec (absdegdeci dirncardinal) >> "Deg-decimal to DMS format output" >> (if (minusp absdegdeci) >> "error - cannot handle negative arguments" >> (let ((decix60 (* (mod absdegdeci 1) 60))) >> (format "%03dd %02d' %04.1f'' %s" (truncate absdegdeci) (truncate decix60) >> (* (mod decix60 1) 60) dirncardinal)))) >> >> For example - Berry Head lighthouse is at (North, East) >> 50.39954886056384, -3.483553379652956 >> (lat-long-degdeci-to-dms 50.39954886056384 -3.483553379652956) >> "050d 23' 58.4'' N 003d 29' 00.8'' W" >> which is correct - that is the position of Berry Head lighthouse on a >> nautical chart which uses the "WGS84" datum. >> If you paste >> 050 23' 58.4" N 003 29' 00.8" W >> into Google Maps it will show a pin on the lighthouse... >> >> But all of this done in total isolation >> (learned Lisp-style programming from a book 20 years ago with Paul >> Graham's "On Lisp" >> http://www.paulgraham.com/onlisp.html) >> >> So have no idea whether there might be much better ways of achieving >> the goal. >> >> >> Computers and Computing - 10 year old "mac-air" still going and couple >> of years ago managed to get it to upload lots more software from >> "fink" site, so all happiness there. >> >> Which has left the "Raspberry Pi" computer, which works wonderfully, >> neglected. >> >> By the way I learned Linux when needed a supercomputer in the 1990's. >> >> Had doing 10's of hours runs when then "Windows95" would "fall-over" >> about every 4 hours and couldn't really be used at all for ad-hoc >> programming (no segmentation -> allocated space, and only that space, >> in which a program is permitted to run). >> >> I'd have some use of an embedded device - eying the Raspberry Pi card >> which came with the computer >> Measure something like hydraulic pressure from a sensor, log it and >> maybe control something to do with that hydraulic pressure. >> >> Anyone interested in any of these things? >> -- >> The Mailing List for the Devon & Cornwall LUG >> FAQ: https://www.dcglug.org.uk/faq/ > > Hi Rich. > > Bit late here but do some playing with Lisp - retired now and using the > opportunity to play with stuff I started to dig into for work 40 years ago so just > dug out lisp-kit and found a pdf copy of the book online. Also dug out the old > aima lisp code to have a play. Found some Prolog for it too but thats seriously > out of date. Kinda fun to get both historical ends of AI to meet! > > Up near Holsworthy which is in the north and west of Devon but apparently not in > North Devon or West Devon! > > Tom te tom te tom > > -- > The Mailing List for the Devon & Cornwall LUG > FAQ: https://www.dcglug.org.uk/faq/ Hi Tom Good to hear from you. A person who’s actually used Lisp! Maybe some projects? Not too bad to get to Holsworthy from West Cornwall. Rich S -- The Mailing List for the Devon & Cornwall LUG FAQ: https://www.dcglug.org.uk/faq/