|
Powers of Matrices on 49G
|
|
|
|
« Next Oldest | Next Newest »
|
▼ 
11-25-2002, 06:16 PM
I have been searching the manual for about ½ hour to find out how I raise a matrix to for example 7. I am not sure exactly what it is called so here is an example: [Matrix]^7 BTW are there more places to get help for HP calculators than here? I would like to know if there was newsgroups and more forums and so. ▼
11-25-2002, 08:02 PM
First, I have to say that I don't know what the result of raising a matrix to a power should be. Assuming that your 49G is in RPN mode, enter the matrix (for example, [[ 1 2 ] [ 3 4 ]]), enter the exponent (7 in this example), and press the YX ([Q]) key. The 49G returns [[ 30853 44966 ] [ 67449 98302 ]]. Is that correct? A newsgroup that discusses the 49G is comp.sys.hp48. Don't let the "hp48" part discourage you; it includes "similar" calculators, that is, the 28 series, 48 series, 49G, and even the 38G, 39G, and 40G, and occasionally other calculators. I think that the 49G is probably the most often discussed calculator on the newsgroup lately. For an archive (about 99,800 threads at the momemt) of the newsgroup visit http://groups.google.com/groups?q=comp.sys.hp48. For a huge source of information visit http://www.hpcalc.org/. You can also tap into the HP48 Ring at http://www.webring.org/cgi-bin/webring?ring=hp48&list. To get the most up-to-date flash "ROM", visit http://www.epita.fr/~avenar_j/hp/49.html. In general search the web for "HP 49" or "HP 48".
Regards, ▼
11-25-2002, 08:39 PM
The TI-83 (dare I mention it?) gives the same answer (is that confirmation, or the opposite?), and its manual is clear about how to do it. (This is one reason HP is in trouble.) Since the TI-83 is algebraic, it is just entered as [Matrix]^7. Of course the matrix has to be square in order to be multiplied by itself.
11-28-2002, 03:12 PM
Interesting! This brings up the logical question: How would one perform A^7 on other HP's with built-in matrix support? Here are my answers: HP-42S: y^x is not supported for matrices. Don't use the x^2 function, because that will only square each matrix element. Instead, after loading the square matrix with the descriptor in the X-register:
ENTER, ENTER, ENTER, X, X, X, X, X, X
The result matrix cannot be stored to the same name (A, B, C, D, or E) as the name of either multiplicand matrix. With the square matrix loaded into "A": RCL MATRIX A, ENTER, RESULT B, X, ENTER, RESULT C, X, RCL MATRIX B, RESULT D, X, RCL MATRIX A, RESULT B, X A bit cumbersome, but there's enough memory to perform A^7 (or any n) for a 4x4 real-valued matrix A!
Suggestions? I have the eqipment, but haven't learned the added-on matrix functions for the 41.
11-25-2002, 08:17 PM
Put the matrix on level 1. Put 7 on level 2. Press Y^X. News Group: comp.sys.hp48 Raul ▼
11-26-2002, 03:54 PM
I have done exactly what you suggested and as I thought I should do, but I get this error message: Will an update of the calculator solve that problem? ▼
11-26-2002, 04:16 PM
I use a 48GX with Erable: that's exactly what I must do for getting the result. I tested it in my "virtual" 49 (emu48) before posting, and, as expected, I got the same answer. Raul
11-27-2002, 01:50 AM
You should have the matrix on level 2 and the exponent on level 1 before you press the YX key. I don't know about the other ROMs, but it works for me with both revision 1.18 and revision 1.19-6.
Regards,
11-27-2002, 02:45 AM
As James says, just upside down: matrix in level 2 and exponent in level 1. |
