topic Re: Mathcad prime 5.0 in Mathcad

Mathcad prime 5.0

BB1 — Tue, 18 Dec 2018 14:10:38 GMT

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

Re: Mathcad prime 5.0

terryhendicott — Tue, 18 Dec 2018 08:09:11 GMT

Hi,

you just use:-

Regards

Terry

Re: Mathcad prime 5.0

terryhendicott — Tue, 18 Dec 2018 08:12:06 GMT

Hi,

I will try this post again to get the graphic:

You just use:-

Cheers

Terry

Re: Mathcad prime 5.0

BB1 — Tue, 18 Dec 2018 08:38:45 GMT

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

Re: Mathcad prime 5.0

terryhendicott — Tue, 18 Dec 2018 08:38:22 GMT

Hi,

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

Cheers Terry

Re: Mathcad prime 5.0

BB1 — Tue, 18 Dec 2018 11:18:51 GMT

Please check attachment.

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

Re: Mathcad prime 5.0

terryhendicott — Tue, 18 Dec 2018 12:03:19 GMT

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

Re: Mathcad prime 5.0

Werner_E — Tue, 18 Dec 2018 17:05:40 GMT

@BB1 wrote:

Please check attachment.

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.

See here: https://community.ptc.com/t5/PTC-Mathcad/Mathcad-prime-5-0-matrix-multiplication/m-p/585721/highlight/true#M183830

Re: Mathcad prime 5.0

Werner_E — Tue, 18 Dec 2018 17:48:49 GMT

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.

Re: Mathcad prime 5.0

BB1 — Wed, 19 Dec 2018 00:51:41 GMT

I need the solution in symbolically..means interms of variables like in X,y

Re: Mathcad prime 5.0

BB1 — Wed, 19 Dec 2018 09:12:01 GMT

Thanks for your answer, please check the attachment.

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).

Thanks In advance.

Re: Mathcad prime 5.0

Werner_E — Wed, 19 Dec 2018 09:53:26 GMT

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.

Re: Mathcad prime 5.0

BB1 — Wed, 19 Dec 2018 10:03:41 GMT

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...

Re: Mathcad prime 5.0

Werner_E — Wed, 19 Dec 2018 10:13:50 GMT

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 =).