cancel
Showing results for
Did you mean:
cancel
Showing results for
Did you mean:

The PTC Community email address has changed to community-mailer@ptc.com. Learn more.

5-Regular Member

## Mathcad prime 5.0

I wanted to create the Y BUS matrix from Netlist and solve that to get currents and voltages of each node.

For this i need to know how to solve the AX=B in matrix format, if all matrices(A,X and B) having variables only,

I want X in terms of Varibales(eqn)

Please check the 29th page of this pdf:

http://www3.imperial.ac.uk/pls/portallive/docs/1/7292571.PDF

1 ACCEPTED SOLUTION

Accepted Solutions
24-Ruby V
(To:BB1)

You may possibly be able to do what you are looking for, but as long as an expression contains an unknown/undefined variable you obviously can't evaluate that expression or function numerically (that means using the normal =).

13 REPLIES 13
21-Topaz I
(To:BB1)

Hi,

you just use:-

Regards

Terry

21-Topaz I
(To:BB1)

Hi,

I will try this post again to get the graphic:

You just use:-

Cheers

Terry

5-Regular Member
(To:terryhendicott)

Please check the attachment, that one i am not able to solve

21-Topaz I
(To:BB1)

Hi,

The inverse of a matrix times the matrix is the identity matrix (all zeros except diagonals being one)

Cheers Terry

5-Regular Member
(To:terryhendicott)

why the same inverse is not working in program?, but outside its working fine,

21-Topaz I
(To:BB1)

Hi,

Symbolic outside of the program does not need x and y to be defined to work.

Numeric inside the program needs x and y defined as numerical values to calculate the inverse.

Cheers

Terry

24-Ruby V
(To:BB1)

@BB1 wrote:

why the same inverse is not working in program?, but outside its working fine,

It will work OK inside a program. too, but only if you evaluate the program symbolically, not numerically.

24-Ruby V
(To:BB1)

Do you really need a general symbolic solution? It looks a bit uncomfortable:

Wouldn't do a numerical solution do the job good enough?

You may either use the matrix approach or a solve block with the original node equations.

5-Regular Member
(To:Werner_E)
I need the solution in symbolically..means interms of variables like in X,y
5-Regular Member
(To:Werner_E)

The first two are giving properly and last one is not solving, am i missing anything or it cant solve??.

I need the answer for last one in program, Nett(FF).

24-Ruby V
(To:BB1)

Always post the worksheet, not just pictures!

Why don't you just define Nett(B):=B^-1

Guess you don't need a global definition

Then you could use Nett(FF)->

As long as FF contains unknown variables you cannot evaluate your function Nett numerically.

5-Regular Member
(To:Werner_E)
As you said I can do, but the thing is my matrix will have only variable
and need to get some required data from that matrix using programming,
after that I need to form one matrix out of the main matrix, that matrix
also in variables only and finally need to do inverse of the matrix which I
formed from the main Matrix.

Everything it should solve symbolically,

Thanks for your patience...
24-Ruby V
(To:BB1)

You may possibly be able to do what you are looking for, but as long as an expression contains an unknown/undefined variable you obviously can't evaluate that expression or function numerically (that means using the normal =).

Announcements