Big help needed!!!!!!

[MikeArmstrong]

I am working on the attached program which calculates the pipeweight required for certain sea conditions, so far I have calculated the velocity and acceleration correctly.

Well the correct answers........

I am trying to have the following parameters as multiple inputs.

� Depth from surface to seabed
� Combined OD of pipes
� Period of wave
� Significant height of wav
� Steady state current

This will allow the user to run multiple stability analyses at once.

Any help will be greatly appreciated.


Regards

Mike

[ptc-1368288]

1. Why plug two same values in d, T, H ?
The vectorize opetor does repair but you must repair by single value in each.
2. As in 1/. above, the solver solves for a scalar, i.e: you don't have a vector of solutions, just the kernel display. Why carry or attempt to carry two same solutions ?
3. Why programs instead of the functions ?
4. What is L ? and you initialise with such a specific value that it makes the reader think why do you need a solver that solves nothing !
5. You have a lengthy introduction and when finally at some function, then NO PLOT. Collabs can't cross check with the BS or else. So, the plot is for you, but if you don't mind checking your result .. what is the point of a work sheet ? !
6. nest2mat(ucc) is not needed ... same as UCC.
7. a_max seems to locate some "peak" of acceleration ... at least here you have only two [�] but eventually there may be lot more. If such functionality is needed there are functions in Mathcad "locating min/max".
An Engineering work sheet should resemble an "Engineering work sheet".
You can finish on your own, following the guide lines.

jmG

[MikeArmstrong]

jmG
1. D,T & H are the same so can I go through each of the calculation steps I can check if they come out the same, then the values can be changed by the user.

4. L is wave length needed is the calculation.

5. I haven�t finished the sheet and plots will be created for each of the velocity and accelerations calculated.

6. Understood.

7. Understood.

I have attached a copy of my latest worksheet, any comments would be welcome.


Regards

Mike

[ptc-1368288]

Comments:

1. Make your project live in d, T, H
2. Wave results in same style as d, T, H
3. Don't initialise L with one of the result, in other situations it will simply fail.
4. Theta is Theta and goes in Theta. Nothing wrong with what you did, but most confusing and useless and you don't have to define wild, just live.
5. Certainly nothing wrong with the utilities as their source is from Mathcad chevron, if you need some just plug the ones you need. That makes a long work sheet prone to fail between versions.
6. You want to stick with units, up to you but you don't have an export therefore no analysis done. The trick to plot is the most glorious idiosyncrasy you will see in Mathcad. Sorry if it qualifies their adepts, but Engineers work with Engineering formulas that are scaled/sized in the unit system and just need the "UserUnitResult" appended.



7. Try to make more work past the plot so it can be seen what more you are attempting.

Don't be short of description/tutorial, the project has no abstract. If you change style of work in every posting, I can't follow indefinitely. Do your best in that one for the remaining and repost, that means work past the the plot. Indexed subscript turn out very confusing [Hs].

jmG

[MikeArmstrong]

jmG

Please find attached my latest calculation sheet, I have annotated throughout the sheet to try and explain what I have done and what has changed from the previous example.

Please remember I am short on experience using Mathcad, 2 years to date.

Any recommendations to the attached sheet will be welcome the sheet now calculates exactly what is required.


Regards

Mike

[RichardJ]

On 8/26/2009 1:58:25 PM, Armo wrote:

>Any recommendations to the
>attached sheet will be welcome

Wavelength is one word 😉

Richard

[MikeArmstrong]

Cheers

Regards

Mike

[ptc-1368288]

On 8/26/2009 1:58:25 PM, Armo wrote:
>jmG
>...
>Please remember I am short on
>experience using Mathcad, 2
>years to date.
>
>Any recommendations to the
>attached sheet will be welcome
>the sheet now calculates
>exactly what is required.
>
>
>Regards
>
>Mike
_______________________________

Very good work, few more things:

1. At the stage of collaboration, leave all Mathcad as default: auto display, yellow highlight, variables TNR black, constants TNR black, auto-grid plots, grey 225 grid, show arguments, global definitions as triple equal ...
2. Nothing wrong to display an Excel data table but totally wrong to use it if not needed and it is never needed in Mathcad.
3. Watch carefully where you had zillions of 'j' , I zapped all of them not needed .
4. The scripted component will be for you once you don't have to attach work sheets in the collab. Scripted components can carry viruses. Not sure if you can "define global" the scripted component and drag at the point of interest of the project ... if you can't drag at the point of interest in the work sheet then zap ... I did zap for checking where the project goes.
5. I read as far as red ? 72 and don't understand the "phase angle".
6. I zapped the "Vector utilities" as it seems not needed at all, especially not needed if it can be done in Mathcad native style.

Not bad at this point, plenty of plots to check and check as per the "selected run J" near each pertaining part of the project.

If you are doing in version 14, not bad compatibility at all, down to 11.


jmG

[MikeArmstrong]

Thanks again for looking at my worksheet.
I will number my responses again your numbered comments and try and explain my logic.

1. Agree

2. The Excel table is shown as it is asthetically pleasing on the eye, when we send calculations out to clients all input data has to be shown.

3. You have zapped all the zillions of �j�, but now only I stability run can be analysed at once.

4. Agree

5. The phase angle is only present to indicate at what phase of the wave the maximum horizontal force and submerged weight is required.

6. The Mathcad native style which you have provided seems more complicated that the vecrange in the original sheet, I can�t see a logical reason for not using the vecrange.

Regards

Mike

[ptc-1368288]

2. The Excel table is shown as it is aesthetically pleasing on the eye, when we send calculations out to clients all input data has to be shown.
==> OK as a dead item but don't use it, define the data as a Mathcad input table.
==> Better: plug the Excel table as an image

3. You have zapped all the zillions of �j�, but now only I stability run can be analysed at once.
==> Scripted components can carry viruses ... tell that to your client !
==> You can have only one(1) analysis at time, whichever way.
==> with 'J global' you can have anywhere at the point of interest in the work sheet.
==> If you can't define "scripted component globally" and drag , no use.
==> a really ridiculous item that does not support the Mathcad functionality.
==> and that makes the plot argument senseless and confusing.

5. The phase angle is only present to indicate at what phase of the wave the maximum horizontal force and submerged weight is required.

6. The Mathcad native style which you have provided seems more complicated that the vecrange in the original sheet, I can�t see a logical reason for not using the vecrange.
==> vecrange is a monkey business,
_(low,high,npts) is visible, short, very fast and existed from Mathsoft before vecrange . There are several versions of these discretizers, each one has sometimes an application vs another one. A matter of choice as you are the man sending the analysis to the client. The Mathcad native structure is very powerful, it takes years to master sufficiently well, think in term of the client just being simply more logical than vecrange.
==> the last step for you is the data table of all the calculated values. It is a must for every project that calculations result in a fixed printed document for record and analysis outside of Mathcad for in-situ journey and dispute in the court room.
==> I'm saying that because you have used units and can't immediately augment(,,,,,) for the analysis data table. You have now to introduce another monkey business to dismantle the units system that should not have been used from beginning. Simple: zap the unit system completely and dimension and convert as needed depending upon the client own unit system. Just like any normal Engineering work, easy to check from Engineering formulas. Use the Mathcad unit system for the conversion and coherence, as the front end of the work sheet ...even then, checkers will use conversion table and/or pocket calculators. No matter how reliable the Mathcad unit system is, it is a non visible part of the Engineering work that is not traceable unless scratching the left ear with the right hand. What I'm saying, in other words, a Mathcad work sheet carrying units is not the image of standards/codes/handbooks.
Again think in term of the client wondering why a Mathcad work sheet would have to carry units vs his local codes/handbooks. Convert first and run the formulas as they are, splitting the traceability, fully visible.

jmG

[ptc-1368288]

>This will allow the user to run multiple stability analyses at once.<<br> ____________________________

Nope ! because you CAN'T collect and export. Carry units as much you feel/need on a scratch work sheet, but not in an "Engineering work sheet".



jmG

[MikeArmstrong]

It seems I have sorted the problem, I was defining i (integer) a range variable, Instead I have used the (vecrange) function from the vector define functions sheet.

Cheers for all the help.

Regards

Mike