# Solving simultaneous equations for mesh analysis

Discussion in 'Math' started by bendi, Jul 6, 2011.

1. ### bendi Thread Starter New Member

Jan 1, 2011
1
0
Hi
Can anybody advise whether there is an online or down-loadable calculator for mesh analysis solving complex notation such as a + jb using determinants and calculating for two or three unknown variables? Thanks in advance.

Mark (Bendi)

2. ### blah2222 Well-Known Member

May 3, 2010
554
33
Matlab will do it.

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Feb 16, 2010
112
5
Also, Octave is a free command-line version of MATLAB which will probably do it. Does anyone know if a TI-89 will do it? I've never tried rref() with matrices containing complex numbers.

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4. ### t06afre AAC Fanatic!

May 11, 2009
5,939
1,222
The HP graphics calculators will do it.

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Jul 7, 2009
1,585
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You can do it with python and scipy which are freely downloadable tools:

Code ( (Unknown Language)):
1.
2. from scipy import *
3. from scipy import linalg
4.
5. A = mat("[1 3 5; 2+1j 5 1; 2 3 8]")
6. b = mat("[10;8;3]")
7. print A.I*b   # .I means to take the inverse
8. print linalg.solve(A, b)
9.
(note the complex number in the second row of the matrix) which produces

Code ( (Unknown Language)):
1.
2. [[-8.21529745+2.95750708j]
3.  [ 5.39660057+0.6572238j ]
4.  [ 0.40509915-0.98583569j]]
5. [[-8.21529745+2.95750708j]
6.  [ 5.39660057+0.6572238j ]
7.  [ 0.40509915-0.98583569j]]
8.
The example shows both matrix inversion and a linear equation solver (the solver is preferable because it is numerically more stable).

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6. ### guitarguy12387 Active Member

Apr 10, 2008
359
12
TI-89 will do it!

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7. ### victorhugo289 Member

Aug 24, 2010
49
3
You'll definitely might want to look at Qalculate, it's a calculator for Linux, i use it on Ubuntu all the time, I managed to overwrite the ABC.. constants that have been programmed into it and I used them as XYZ variables so I can solve any equation that uses ABCD..etc variables.
It solves for values, it factorizes, it simplifies, it's amazing.
I use it only for simple Algebra, but you can definitely solve the complicated stuff in there.

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8. ### Jony130 AAC Fanatic!

Feb 17, 2009
3,962
1,097
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9. ### jfrost New Member

Dec 22, 2010
6
1
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