HP48GX User Guide Cover Plot - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: General Forum (/forum-4.html) +--- Thread: HP48GX User Guide Cover Plot (/thread-17786.html) |
HP48GX User Guide Cover Plot - DM48 - 12-04-2021 01:52 AM Does anyone have the equation that is displayed on the screen of the HP48G(X) user guide? I would like to plot it and can't find any reference to it. RE: HP48GX User Guide Cover Plot - BruceH - 12-07-2021 12:55 AM In the absence of other replies I'll chip in my 2p. I don't think it is an equation plot - at least not in the sense of using one of the built-in tools to graph it. It looks to me more like a graphic generated by a program and so your question becomes: hows does the program generate that 'graph'? There are probably several ways to do it. One would be to generate a matrix of a uniform 2d grid and then distort the grid by multiplying by matrices. (Folding the grid up into a U shape first; then wrapping the result around the outside of a 'wheel' would seem to be a good start.) RE: HP48GX User Guide Cover Plot - Dave Frederickson - 12-07-2021 01:03 AM It looks like a saddle surface. https://en.wikipedia.org/wiki/Saddle_point#Saddle_surface z = x^2 - y^2 RE: HP48GX User Guide Cover Plot - nlj - 12-07-2021 02:34 AM (12-04-2021 01:52 AM)DM48 Wrote: Does anyone have the equation that is displayed on the screen of the HP48G(X) user guide? I would like to plot it and can't find any reference to it. Is it a rotated view of the wireframe plot in the example on Page 23-30? (I'm looking at the HP 48G Series User's Guide, Edition 8.) In that case, it is z = x^3 y - x y^3. But perhaps the one on the cover is not as convoluted as that one is. RE: HP48GX User Guide Cover Plot - DM48 - 12-07-2021 03:57 AM I just found this. “The HP 48GX advanced scientific graphing calculator displays a wireframe plot of the surface z = x3y - xy3.” https://www.hpl.hp.com/hpjournal/94aug/covaug94.htm RE: HP48GX User Guide Cover Plot - DM48 - 12-07-2021 03:59 AM (12-07-2021 02:34 AM)nlj Wrote:(12-04-2021 01:52 AM)DM48 Wrote: Does anyone have the equation that is displayed on the screen of the HP48G(X) user guide? I would like to plot it and can't find any reference to it. I think you nailed it. I’m going to try and graph it and see what happens. RE: HP48GX User Guide Cover Plot - DM48 - 12-07-2021 12:18 PM Plotted. I just need to determine how to rotate it if possible. Any ideas? Photo here: https://imgur.com/a/Bm2uugB RE: HP48GX User Guide Cover Plot - nlj - 12-07-2021 04:30 PM (12-07-2021 12:18 PM)DM48 Wrote: Plotted. I just need to determine how to rotate it if possible. Any ideas? Maybe something like: EQ: Z = Y^2 - X^2 XE: -1.4 YE: -2 ZE: -0.6 Step Indep: 14 Depnd: 10 and a window of -1 to 1 for X, Y, and Z. It looks quite close but I have a nagging suspicion that it is inside out and an optical illusion flips it in the mind's eye from front to back! [attachment=10165] In comparison to the one on the cover of the manual: [attachment=10166] RE: HP48GX User Guide Cover Plot - JoJo1973 - 12-07-2021 06:42 PM (12-07-2021 12:18 PM)DM48 Wrote: Plotted. I just need to determine how to rotate it if possible. Any ideas? Let the 48GX be your TEACHer: within its trove of treasures for EXAMPLE, in an unintended twist of PLOT you'll be able to use a WIRE and catch the knowledge you desire! )) RE: HP48GX User Guide Cover Plot - DM48 - 12-07-2021 11:40 PM (12-07-2021 04:30 PM)nlj Wrote:(12-07-2021 12:18 PM)DM48 Wrote: Plotted. I just need to determine how to rotate it if possible. Any ideas? Thank you. I was able to reproduce your results using YOUR equation. Many thanks. It's close to the user guide, but not quite the same perspective. I will work on it. I am going to continue to look at the equation that seems to be the one HP is convinced they used, but I am not so sure it is. Interesting issue! |