Complex numbers HP32SII ravwalia Junior Member Posts: 24 Threads: 8 Joined: Jan 2008 01-09-2008, 04:59 PM ```Hello Everyone, I have an equation which is the relationship between reflection coefficient and impedance r=(ZL-ZS)/(ZL+ZS) ZL and ZS are complex numbers. Typical ZS is always 50+j0. At the moment I am doing the following for the calculation ZL imaginary part ENTER ZL real part ENTER ZS imaginary part ENTER ZS real part ENTER COMPLEX - Then this gives me the numerator, I write this down and then ZL imaginary part ENTER ZL real part ENTER ZS imaginary part ENTER ZS real part ENTER COMPLEX + To get the denominator and again write this down. Finally I enter the complex numbers in again and / to get the reflection coefficient in rectangluar form and then finally convert it to polar. I tried writing a program for this but the answer came out completely wrong, though if I do it by hand it's okay. Anyone have any hints on how to start this? Also anyone have any RF programs they would like to share? Does the HP35s handle complex numbers better, so that I could use it as an excuse to buy one? Thanks, Rav ``` Jeff Kearns Member Posts: 222 Threads: 21 Joined: Oct 2006 01-09-2008, 07:02 PM Hi ravwalia, Can you please provide the values you are using? It seems like a simple error when I read your post: When you divide the two complex numbers (i.e. numerator and denominator) you must also press LEFT SHIFT CMPLX prior to executing the division. I also own the 35s and it does seems to have a much improved COMPLEX Operations implementation in that you can treat complex numbers as you do real numbers (without always pressing LEFT SHIFT CMPLX prior to executing the operation) and you actually enter the numbers in a more logical sequence - real part first, then imaginary part. The 35s has can also accommodate up to four separate complex numbers in the complex stack as opposed to only two as in the 32sii - that is a big selling point to me! This makes it 'almost' as good as the 15C in this regard. Verdict: If you do a lot of COMPLEX operations, you will like the 35S. I haven't figured out a way to directly enter a number like: 2-4*SQRT(5)i, as one can easily do with the famous 15C... Oh well. Jeff Jeff O. Posting Freak Posts: 875 Threads: 37 Joined: Jul 2005 01-09-2008, 08:25 PM Are you sure the keystrokes given above will give the right answer? It looks to me like you have an extra ENTER in each sequence. The last ENTER before you do the complex operation would push the imaginary part of the first number off of the top of the stack and screw up the complex numbers that you are operating on. If your program somehow does this, that would explain why it gives incorrect answers. What is your program listing? I don't have a 32SII in front of me, but an off-the-cuff program to do want you want might be as follows: ```LABEL A STO A Rv STO B Rv STO C Rv STO D Rv COMPLEX + STO E x<>y STO F RCL D RCL C RCL B RCL A COMPLEX - RCL F RCL E COMPLEX / R->P STOP ``` Enter your ZL and ZS values as you described (without the last ENTER), press XEQ A and it will give you your answer in polar form without writng any intermediate answers down. As Jeff K stated, the 35s handles complex numbers in a much more natural way. The only thing worth mentioning is that it does not do Polar to Rectangular and Rectangular to Polar conversions in a manner comparable to the 32SII. It does however let you enter the numbers in either polar or rectangular form, operate on them, and change the display mode to either polar or rectangular. For example, for your problem you could put the calculator in polar display mode, enter your numbers in rectangular form, operate on them, and when complete the answer would be displayed in polar form. The complex number handling capabilities and polar to rectangular conversion capabilities of the 35s generated MUCH discussion last summer when the 35s was released. Search the archives for more information. Trent Moseley Senior Member Posts: 406 Threads: 47 Joined: Jul 2005 01-09-2008, 09:13 PM Or the other famous 42S. tm Jeff O. Posting Freak Posts: 875 Threads: 37 Joined: Jul 2005 01-09-2008, 10:10 PM Quote: I haven't figured out a way to directly enter a number like: 2-4*SQRT(5)i, as one can easily do with the famous 15C... how about: ```5 SQRT 4 * i * CHS 2 + ``` I think the 15C would require the following: ```5 SQRT 4 * CHS Re<>Im (back-arrow) 2 ``` And the 42S: ```2 ENTER 5 SQRT 4 * CHS COMPLEX ``` Karl Schneider Posting Freak Posts: 1,792 Threads: 62 Joined: Jan 2005 01-10-2008, 12:23 AM Jeff -- Quote: Verdict: If you do a lot of COMPLEX operations, you will like the 35S. I haven't figured out a way to directly enter a number like: 2-4*SQRT(5)i, as one can easily do with the famous 15C... Oh well. That's a bit easier in Algebraic (ALG) mode: ```MODE 4 2 - 4 i * SQRT 5 ENTER ``` Despite its lack of one-screen complex-number display, the HP-15C's complex-number handling is much better. The HP-42S is better yet. -- KS George Bailey (Bedford Falls) Senior Member Posts: 335 Threads: 12 Joined: Dec 2007 01-10-2008, 02:40 AM In the 35s you would enter R=(A-B)/(A+B) as an EQN equation just the way I wrote it down here. Then you display the equation list and solve for R (EQN Right-Shift R) and enter complex numbers A and B each once when prompted: real part followed by pressing i and then imaginary part and R/S. You can then read R from the display either in rectangular or in polar form, depending on how you've set the display mode. A matter of 10 seconds... ravwalia Junior Member Posts: 24 Threads: 8 Joined: Jan 2008 01-10-2008, 12:19 PM Quote: Hi ravwalia, Can you please provide the values you are using? It seems like a simple error when I read your post: When you divide the two complex numbers (i.e. numerator and denominator) you must also press LEFT SHIFT CMPLX prior to executing the division. I also own the 35s and it does seems to have a much improved COMPLEX Operations implementation in that you can treat complex numbers as you do real numbers (without always pressing LEFT SHIFT CMPLX prior to executing the operation) and you actually enter the numbers in a more logical sequence - real part first, then imaginary part. The 35s has can also accommodate up to four separate complex numbers in the complex stack as opposed to only two as in the 32sii - that is a big selling point to me! This makes it 'almost' as good as the 15C in this regard. Verdict: If you do a lot of COMPLEX operations, you will like the 35S. I haven't figured out a way to directly enter a number like: 2-4*SQRT(5)i, as one can easily do with the famous 15C... Oh well. Jeff ``` Hello All, I apologise for not being more precise in my question. Firstly in the listing above there is an extra ENTER before each of the complex command. Those should not be there as the stack is already filled. I can perform the calculation by hand but this is something that I do a lot and 99% of the time ZS is always 50+j0. So I thought that a program would be better. However, when I put in the program, this first one I have ever written, and used the test case ZL=40+j70 and ZS=50+j0 I get the wrong answer, doing it by hand I get the correct one. I just programmed it in as the keypresses I was using and it was still wrong. It looks like I might have a good excuse to get the HP35S. I'll try the program listing suggested and report back. Thanks, Rav. ``` ravwalia Junior Member Posts: 24 Threads: 8 Joined: Jan 2008 01-10-2008, 12:29 PM ```This program did it very nicely. Thanks for this. I'll print this out and see if I can work out what's going on. Thanks again, Rav. ``` ravwalia Junior Member Posts: 24 Threads: 8 Joined: Jan 2008 01-10-2008, 12:31 PM Seems like a really nice and intuitive way to do it. I'm really tempted to get a HP35s now. Thanks, Rav. « Next Oldest | Next Newest »

 Possibly Related Threads... Thread Author Replies Views Last Post HP Prime: complex numbers in CAS. Alberto Candel 1 913 12-06-2013, 02:36 PM Last Post: parisse [HP Prime] Plots containing complex numbers bug? Chris Pem10 7 1,814 12-05-2013, 07:40 AM Last Post: cyrille de Brébisson Complex Number Entry on Prime Jeff O. 19 2,825 11-16-2013, 12:34 PM Last Post: Jeff O. comparing numbers on the WP 34S Kiyoshi Akima 7 1,444 10-19-2013, 09:28 AM Last Post: walter b HP Prime: Operations with Large Numbers Eddie W. Shore 0 510 10-19-2013, 12:24 AM Last Post: Eddie W. Shore HP Prime complex results Javier Goizueta 0 559 10-06-2013, 12:59 PM Last Post: Javier Goizueta HP Prime Solving Nonlinear System of Equations for Complex Results Helge Gabert 11 2,226 09-30-2013, 03:44 AM Last Post: From Hong Kong HHC 2013 room numbers David Hayden 2 764 09-20-2013, 05:34 PM Last Post: sjthomas [HP-Prime xcas] operations with complex numbers + BUGs + Request CompSystems 9 1,828 09-08-2013, 10:40 PM Last Post: CompSystems TED Talk: Adam Spencer: Why I fell in love with monster prime numbers Les Bell 3 936 09-05-2013, 12:54 PM Last Post: Ken Shaw

Forum Jump: