I still use my HP200LX for exactly that reason, the equation solver. When got a PDA I put in requests to various calc developers for 200LX equation solver clone, but to no avail. Would be nice to see one for tablets/smartphones. Terry ________________________________ From: Ken Wyatt <ken@xxxxxxxxxxxxxxxx> To: Martin Euredjian <martin_05@xxxxxxxxxxxxxx> Cc: "si-list@xxxxxxxxxxxxx" <si-list@xxxxxxxxxxxxx> Sent: Saturday, February 25, 2012 4:36 PM Subject: [SI-LIST] Re: OT: Mobile apps for engineers Hi Martin, Please excuse the delay, as I'm going through older emails today. HP did it right with the HP 95, 100 and 200LX clamshell PDA/calculators. They built in a super equation solver where you could enter in a generalized formula, defining named variables. Once the equation was entered/saved, you could scroll down the list of equations, select one and it would display all the variable names. Entering data for any of the names, but one, would solve for the one. That's what I would very much like to see on the iPhone. Cheers, Ken _______________________ Kenneth Wyatt Wyatt Technical Services LLC Woodland Park, CO Email Me! | Web Site | Blog Subscribe to Newsletter Connect with me on LinkedIn On Nov 1, 2011, at 10:37 PM, Martin Euredjian wrote: > I forgot to mention this. There are spreadsheet tools available for iOS. > Frankly, they are a little bit of a pain to use. If you fly in Excel you'd > hate having to poke everything with your fingers. It's clunky and slow. I > have used them but only when I absolutely, positively have no other choice. > There is no way I'd develop the kinds of complex calculation sheets I've done > in Excel on a phone or even on an iPad. > My focus, in terms of mobile apps for engineering, would center around apps > that would make sense for us to use. I have a lot of custom code developed > over the years on my HP41 ~ 48. I am looking at some of those tools to see > how well they might translate into this century. > > Even though I have an HP41 emulator on my iPhone I still reach for a real HP > calculator 95% of the time. Of course, it helps to have a small collection > of them spread around the office :-). > > -Martin > > > > ________________________________ > From: alfred1520list <alfred1520list@xxxxxxxxx> > To: Martin Euredjian <martin_05@xxxxxxxxxxxxxx>; si-list@xxxxxxxxxxxxx > Sent: Tuesday, November 1, 2011 3:55 PM > Subject: Re: [SI-LIST] OT: Mobile apps for engineers > > What I would find useful is something more than an App, more like Excel which > is a platform where any number of custom calculations can be implemented. > > I have created a Perl based engine for the Android for myself. It reads a > text file specifying the formula, e.g. for dBm<->dBuV conversion: > > exp(log(10)*($dBm/10-3)) = (exp(log(10)*($dBuV/20-6)))**2 / $R > > you can provide two of the three $dBm, $dBuV, and $R and solve for > the 3rd unknown. You can also have multiple variables on either > of the equal sign. You can only solve for 1 unknown. It also bombs > all the time due to the crude implementation of the Newton's method. > > This is fashioned after the Solver in the antiquated HP 200LX palmtop. > A faithful reimplementation of that gem would be a great tool. > > > Best Regards, > Alfred Lee > > ----- Original Message ----- From: "Martin Euredjian" > <martin_05@xxxxxxxxxxxxxx> > To: <si-list@xxxxxxxxxxxxx> > Sent: Tuesday, November 01, 2011 1:25 PM > Subject: [SI-LIST] OT: Mobile apps for engineers > > >> Over the years I've developed and used a number of custom little tools that >> I've used while designing products. They span a range from optimizing >> resistor divider calculations to analyzing DRAM timing and graphing >> theoretical power distribution network performance. Most all of these I >> wrote in Excel using the embedded VB language. >> Now I am thinking that these and other tools could be of use to others and >> decided to start down the path of defining a number of apps to write >> (initially for iOS) along these lines. >> >> The reason for this post is to reach out to the SI community in order to >> understand what you might need. I know what I've needed when I've done SI >> work on my own boards. I would like to understand what some of you might be >> interested in having as handy tools to use during the course of your work. >> These don't have to be purely SI-related but can span a range of related >> disciplines. >> >> >> Thanks, >> >> -Martin >> >> >> ------------------------------------------------------------------ >> To unsubscribe from si-list: >> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field >> >> or to administer your membership from a web page, go to: >> //www.freelists.org/webpage/si-list >> >> For help: >> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field >> >> >> List technical documents are available at: >> http://www.si-list.net >> >> List archives are viewable at: >> //www.freelists.org/archives/si-list >> >> Old (prior to June 6, 2001) list archives are viewable at: >> http://www.qsl.net/wb6tpu >> >> > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > List technical documents are available at: > http://www.si-list.net > > List archives are viewable at: > //www.freelists.org/archives/si-list > > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu