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+--- Thread: Linear applications (like "ker"...) (/thread-2926.html)
Linear applications (like "ker"...) - salvomic - 01-25-2015 04:11 PM
hi need something like the menu "Linear Application" for matrices in HP50: image, ker, ismom, mkisom functions...
In Prime I can find only "ker()" function, for "kernel" (null space) and "mkisom()", like the HP 50g, but not "isom()" and "image()".
In CAS aren't the other functions, particularly "Image()"?
Is is possible to have them in another way?
Thank you,
Salvo
RE: Linear applications (like "ker"...) - salvomic - 02-17-2015 10:35 AM
please, advise to write a little program to get the command image() like those in HP50g, to calc the image of a linear applications or its associated matrix :-)
Having a matrix, to reduce it (i.e rref()...), find vectors that are linear independent and that form a base...
Please, dr. Parisse, help.
I hope that developers would like to put image() in the next firmware upgrade of Prime, however.
Thanks in advance
RE: Linear applications (like "ker"...) - parisse - 02-17-2015 12:41 PM
image(A) is rref(tran(A)). Indeed tran(A) puts the columns of A that spans image(A) in rows, then rref reduce the rows, and you get the basis with non-0 rows.
BTW, image and mkisom are Xcas commands.
RE: Linear applications (like "ker"...) - salvomic - 02-17-2015 01:45 PM
(02-17-2015 12:41 PM)parisse Wrote: image(A) is rref(tran(A)). Indeed tran(A) puts the columns of A that spans image(A) in rows, then rref reduce the rows, and you get the basis with non-0 rows.
so simply! I didn't think, thank you
I'm defining a function, now.
Quote:BTW, image and mkisom are Xcas commands.
also ker(), if I'm not wrong; but in Prime I find only ker() and mkisom()...
RE: Linear applications (like "ker"...) - Han - 02-17-2015 04:14 PM
If A is your original matrix, you can also simply use rref(A) to determine the pivot columns of A. The pivot columns of A form a basis for image(A). Parisse's solution is much more direct.
As for commands being available in xcas vs the HP Prime, there are many commands in xcas not available on the prime. The CAS in the HP Prime is not an exact duplicate of xcas; I do not believe this was the intended design (I could be wrong).
RE: Linear applications (like "ker"...) - salvomic - 02-17-2015 04:28 PM
thank you Han.
Who, like me, come from HP 50g, perhaps would like to retrieve in Prime all that is in the other HP best calculator. Said that, I understand that not all in the CAS is also in the Prime, sure.
Only I would suggest to the Team of Developers of Prime don't omit some useful commands, perhaps simple but important, like image() or few others...
However the Parisse's solution it's ok for me (also your hints).