The Museum of HP Calculators

HP Forum Archive 19

 Why the theta choice for complex number display in polar form on the HP35s ?Message #1 Posted by Mohammed Hadi on 29 Nov 2009, 12:19 a.m. This is regarding the theta symbol used which is barely distinguishable from numeral 8. I'm wondering why hp chose this symbol instead of the more useful symbol used in the Casio fx-991ES (fx-115ES in the US). If you look-up any introductory electrical circuits textbook for example, you'll find that complex numbers in polar form are written as magnitude (angle symbol) phase where the angle symbol is similar to a numeral 7 rotated (not flipped) by 180 degrees. Now, this symbol should be easily reproducable by the 35s display and clearly distinguishable as a phase/angle separator.

 Re: Why the theta choice for complex number display in polar form on the HP35s ?Message #2 Posted by Thomas Radtke on 29 Nov 2009, 4:14 a.m.,in response to message #1 by Mohammed Hadi Several inconveniences indicate that this calculator has not been made by people who would acually use it.

 Re: Why the theta choice for complex number display in polar form on the HP35s ?Message #3 Posted by Walter B on 29 Nov 2009, 6:20 a.m.,in response to message #2 by Thomas Radtke It's a real pity HP falls back behind previous better solutions. Compare with the 42S. Ceterum censeo: Hp, launch a 43S.

 Re: Why the theta choice for complex number display in polar form on the HP35s ?Message #4 Posted by Thomas Radtke on 29 Nov 2009, 9:00 a.m.,in response to message #3 by Walter B Quote:Compare with the 42S. You can't. It's a different concept. I might be unfair since I never had the original 42S in my hands, but from what I know, there's a lot of stuff hidden in menus, while the 3x concept makes most functions available straight from the keyboard. HP even went (mostly) back from menus when issuing the 32SII. But ... I know your mileage differs significantly ;-).

 Re: Why the theta choice for complex number display in polar form on the HP35s ?Message #5 Posted by Walter B on 30 Nov 2009, 4:32 p.m.,in response to message #4 by Thomas Radtke Hallo Thomas, ich hab' da garnicht über Rechnerleistung gesprochen sondern ausschließlich über ein Anzeigeformat ;) Und da finde ich es halt einfach traurig, dass die Kollegen gegenüber HP-eigenen, besseren Lösungen deutlich abfallen. Man muss da eigentlich das Rad nicht mehr neu erfinden ... (Explaining my previous post) HTH

 Re: Why the theta choice for complex number display in polar form on the HP35s ?Message #6 Posted by John B. Smitherman on 1 Dec 2009, 12:23 a.m.,in response to message #5 by Walter B Quote:Man muss da eigentlich das Rad nicht mehr neu erfinden ... Hi Walter. Why indeed did HP feel the need to reinvent the 32sii? When I look at the 32sii, 33s and 35s I'm really baffled. Regards, John

 Re: Why the theta choice for complex number display in polar form on the HP35s ?Message #7 Posted by Walter B on 1 Dec 2009, 2:04 a.m.,in response to message #6 by John B. Smitherman Hi John (und hallo), Quote: Why indeed did HP feel the need to reinvent the 32sii? When I look at the 32sii, 33s and 35s I'm really baffled. Now I need an explanation from your side ;)

 Re: Why the theta choice for complex number display in polar form on the HP35s ?Message #8 Posted by Vieira, Luiz C. (Brazil) on 30 Nov 2009, 10:11 a.m.,in response to message #2 by Thomas Radtke Quote:(...)this calculator has not been made by people who would actually use it.I´d go further and say that this calculator has not been made by people who actually understand what is it for (perhaps making money is what they had in mind...). Again, Gene Kranz, former NASA´s operation director, said that engineers, mathematicians and scientists (same order of importance each) must exist to provide the technology and its products that financial market needs to survive. China and Japan alone put about half a million engineers and scientists in the market each year. This is about the rest of the occidental world engineers in the same period of time (USA alone goes about 60.000 a year). I totally agree with him. We need more people who understand about the things instead of people who 'understand' how to sale things. Cheers. Luiz (Brazil) Edited: 30 Nov 2009, 10:42 a.m.

 Re: Why the theta choice for complex number display in polar form on the HP35s ?Message #9 Posted by David Hayden on 29 Nov 2009, 10:17 a.m.,in response to message #1 by Mohammed Hadi Quote: If you look-up any introductory electrical circuits textbook for example, you'll find that complex numbers in polar form are written as magnitude (angle symbol) phase where the angle symbol is similar to a numeral 7 rotated (not flipped) by 180 degrees. Unfortunately, math books use the theta symbol for angles, and many of the calculators are aimed right at the high school education market (HP consulted with a group of math teachers on the 48G/GX). So even though I agree that it would make more sense, I suspect that familiarity won out. Kind of like the way familiarity with the TI 83 seems to make it so hard for HP to gain market share in the education market today. :(

 Re: Why the theta choice for complex number display in polar form on the HP35s ?Message #10 Posted by Karl Schneider on 30 Nov 2009, 3:45 a.m.,in response to message #9 by David Hayden It's just plain incorrect to use theta (or alpha, beta, gamma, or phi) as an angle symbol. All of the above Greek letters are commonly used to represent variables containing the numerical value of an angle, not to indicate that an angular value follows. I included this point in a document I prepared about the HP-35s, which I sent to HP's calculator division. -- KS

 Re: Why the theta choice for complex number display in polar form on the HP35s ?Message #11 Posted by Gerson W. Barbosa on 29 Nov 2009, 11:00 a.m.,in response to message #1 by Mohammed Hadi I wish this was the only issue regarding the HP-35s. It is item #17.3 in this comprehensive bug/annoying features list. Besides getting rid of all bugs a new version should round the mantissa so that the exponent is always visible, the way it is done on the HP-33s (Item #10 in Paul Dale's list). It would also be great if keyboard layouts followed a pattern on all HP scientific calculators like they used to (at least for arithmetic operators, +/-, EEX and the ENTER keys). Anyone who often switches from the HP-50G to the HP-33s or HP-35s know what I mean. Regards, Gerson.

 Re: Why the theta choice for complex number display in polar form on the HP35s ?Message #12 Posted by designnut on 29 Nov 2009, 3:11 p.m.,in response to message #11 by Gerson W. Barbosa I am in favor of clarity even at the expense of departing from convention a bit. I favor a taller period so it shows up better. I suggest a little creativity in symbol formation to fit the small readout with emphasis on visibility. It would be a minor adaptation for the user, but more clarity forever. Sam

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