again solveblock

[aprasun]

Hi all

solve block function of the attached file is unable to give answer. I tried mathcad help but without any success. Please have a look and suggest modification. i have MCAD 14.

Aprasun

[MikeArmstrong]

There doesn't seem to a value for h.f

Regards

Mike

[AlvaroDíaz]

On 10/26/2009 7:20:48 AM, Armo wrote:
>There doesn't seem to a value
>for h.f
>
>Regards
>
>Mike

Nor for P also.

Regards. Alvaro.

[TomGutman]

You have six equations in the solve block. You need to be finding values for six variable.

In general, you should not have constraints of the form x=exp where x is an unknown for which you are solving and exp is an expression not involving x. In such a case x should be made a function of the unkowns in exp and removed as a variable. The only constraints that should remain are those that cannot be explicitly solved for one of the variable in terms of the others (or known parameters). While mathematically it may not make any difference, the dimensionality of the formulation can make a big difference as to both the timing and stability of the solving process.

__________________
� � � � Tom Gutman

[ptc-1368288]

On 10/26/2009 5:49:55 AM, aprasun wrote:
>Hi all
>
>solve block function of the
>attached file is unable to
>give answer...
>
>Aprasun
____________________________

I doubt anything will come out of that !
No diagram, no information ... no nothing to follow and check.

jmG

[aprasun]

Even if I seed all the variables and rearrange the last equation, I am still not able to get the answer.

aprasun

[ptc-1368288]

On 10/27/2009 12:00:40 AM, aprasun wrote:
>Even if I seed all the
>variables and rearrange the
>last equation, I am still not
>able to get the answer.
>
>aprasun
______________________________

Even with an answer, if I would check, it would be returned strike red all across: no diagram, no information no nothing to plug in a "checking calculator".



Ps: now add units

[AlvaroDíaz]

On 10/27/2009 12:00:40 AM, aprasun wrote:
>Even if I seed all the variables and rearrange the last equation, I am still not able to get the answer.

Because you don't follow Gutman's indication about the relation betwen the number of equations and variables: one to one. This level of guessing is premonition, vasted experience or (my bet) empathy.

Regards. Alvaro.

[ptc-1368288]

>Because you don't follow Gutman's indication about the relation between the number of equations and variables<<br> _________________________

Your interpretation is incorrect: hf is explicit of the calculated V, R. Thus not needed in the solver, because redundant. There was a monster solve block years ago, it toke a lot of collaboration to eliminate the redundant relationships.

jmG

[TomGutman]

On 10/27/2009 12:00:40 AM, aprasun wrote:
>Even if I seed all the
>variables and rearrange the
>last equation, I am still not
>able to get the answer.
>
>aprasun

Duh! Read my previous post.

__________________
� � � � Tom Gutman

[aprasun]

thanks