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Spreadsheet program for engineering units? (5)
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Can anyone recommend a Windows spreadsheet program that understands engineering units?
E.g. will convert values automatically between units I have specified, and automatically display the units of the results of expressions of values in units e.g. energy (J) / mass (g) / temperature (J) -> specific heat (J/g/K).
Thanks. |
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zdas04 (Mechanical) |
22 Jun 12 9:25 |
Yeah, it is called MathCAD. David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data. |
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swertel (Mechanical) |
22 Jun 12 9:49 |
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I've heard good things about:
Uconeer Good luck,
Latexman |
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Thanks all, but I do want a spreadsheet program. |
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DRWeig (Electrical) |
22 Jun 12 11:35 |
Sounds like an opportunity to write your own and sell it! Good on ya,
Goober Dave
Haven't see the forum policies? Do so now: Forum Policies
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IRstuff (Aerospace) |
22 Jun 12 12:44 |
I use Mathcad and have used Uconeer in the past. BTW, Uconeer was written by a member on this site. Since Mathcad is a bit pricy, an alternative is SMarh Studio, which is similar in concept to Mathcad, but is freeware: http://en.smath.info/forum/yaf_postst1381_SMath-St...
Alternately, TK Solver can handle units and has an Excel add-on that might do what you want.
Speaking of which, if you give more context and more information, it's more likely that someone will be able to come up with a solution. Withholding usage scenarios only makes it harder to find a solution. TTFN
FAQ731-376: Eng-Tips.com Forum Policies
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Excel has the CONVERT() function. |
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I second IRStuff's mention of smath - a great free tool imo. (I do realize it is not what you requested). =====================================
(2B)+(2B)' ? |
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IDS (Civil/Environmental) |
22 Jun 12 18:46 |
Quote:Excel has the CONVERT() function.
... which looks like it was written by the work-experience kid over a coffee break.
I've had a convert UDF on my to-do list for quite some time, and it's still there. I may lift it up the list a bit (but please don't anyone hold there breath waiting). Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
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Quote:
Quote:Excel has the CONVERT() function.
... which looks like it was written by the work-experience kid over a coffee break.
So buy the kid a bagel and tell him to get back to work on it. |
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IDS (Civil/Environmental) |
22 Jun 12 19:57 |
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IDS (Civil/Environmental) |
22 Jun 12 20:18 |
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dik (Structural) |
23 Jun 12 23:28 |
sMathStudio is a free Mathcad (almost) workalike... it's great for the price and does units fairly well.
Dik |
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Here is a useful Excel Book |
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IDS (Civil/Environmental) |
29 Jun 12 19:13 |
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kstifle (Mechanical) |
6 Jul 12 11:58 |
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(2) IDS (Civil/Environmental) |
11 Jul 12 8:56 |
I have just posted my own unit conversion spreadsheet on my blog:
Quote:Looking for a spreadsheet or add-in that would provide better functionality my requirements are:
■Provision of User Defined Functions (UDF’s) for unit conversion, so that the conversion may be easily applied to tabular data anywhere in any spreadsheet.
■A wide range of output units, including all “customary units” used for engineering applications in the USA.
■Editable unit data tables so that new units may be added or corrected.
■Output of converted data in array form, so that the data may be easily used in other UDF’s.
■Preferably free and open source.
None of the existing unit conversion spreadsheets that I’m aware of meet all these requirements (most don’t even come close), so I decided to write my own.
The download file provides open source UDF's to convert to and from SI and a list of 344 non-SI units (taken from Wikipedia).
It's version 0.0, so no doubt there are some errors, and things that could be improved.
Any comments gratefully received.
Download from: http://newtonexcelbach.wordpress.com/2012/07/11/un...
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
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drawoh (Mechanical) |
19 Jul 12 11:14 |
chrisjj,
On the last page of any engineering spreadsheets I do, I set up the last worksheet for engineering conversions and other stuff.
CODE. A B C
1 in =.0254 m
2 ft =12*in m
3 lb =4.45 N
4 furlong =660*ft m
Column B shows the formula, not the values. I name the cells in column B, in this case, "in", "ft", "lb" and "furlong" respectively. Column C is just for information
Anywhere else in my spreadsheet, when I enter a value in units like lb.in, I go =210*lb*in, and it comes out in N.m.
For something like pressure, I would go 14.7*lb/in^2, and it comes out in N/m^2 (Pa). --
JHG |
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Thanks JHG. That's neat. Sounds like you're another user that would like the program I'm looking for! :) |
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IDS (Civil/Environmental) |
19 Jul 12 21:34 |
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E.g. (from my OP) "automatically display the units of the results of expressions of values in units". Hence that I asked for a spreadsheet program rather than a spreadsheet document.
Your spreadsheet document looks like probably the best solution that can be delivered in a spreadsheet document - well done! |
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IDS (Civil/Environmental) |
20 Jul 12 18:02 |
Quote:E.g. (from my OP) "automatically display the units of the results of expressions of values in units".
OK, I can add that. It will look something like:
If you have:
Row 1: a 100 kN
Row 2: b 10 m
Row 3: = a * b (text)
Then =EvalU(A3, A1:C2) will return 1000 kN.m
Or you could use =EvalU("= a * b", A1:C2) with the same result.
Anything else you would like?
I'm not exactly clear what you mean by a "spreadsheet program" as opposed to a "spreadsheet document". Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
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drawoh (Mechanical) |
20 Jul 12 18:37 |
Quote (chrisjj)
Thanks JHG. That's neat. Sounds like you're another user that would like the program I'm looking for! :)
I have the program. It is a spreadsheet.
I can enter my values and the units, and have everything convert to my standard units. Since Excel and Libre (Open) Office allow you to name spreadsheet cells, you have no problems writing out expressions in a format you can understand. --
JHG |
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> I'm not exactly clear what you mean by a "spreadsheet program" as opposed to a "spreadsheet document".
A spreadsheet program is e.g. Excel. a spreadsheet document is e.g. an XLS. A Windows program can do more than can a spreadsheet document. |
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> I have the program. It is a spreadsheet.
The program I described does this:
Quote (Chris) automatically display the units of the results of expressions of values
in units e.g. energy (J) / mass (g) / temperature (J) -> specific heat (J/g/K).
Your spreadsheet, clever though it is, does not do that.
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IRstuff (Aerospace) |
25 Jul 12 11:50 |
"A spreadsheet program is e.g. Excel. a spreadsheet document is e.g. an XLS. A Windows program can do more than can a spreadsheet document."
Again, some confusion in terminology. While Excel is a program, that does not mean that a spreadsheet does not contain a program; to wit, any VBA content means that a spreadsheet document can run a VBA program, and so it's more than just a document, and would be properly described as a "spreadsheet program."
If you mean a Windows program that reads and executes spreadsheets, then you are out of luck; you're back to SMath and Mathcad. TK!Solver is probably the closest thing to what you apparently want:
http://www.uts.com/ItemDetails.asp?ItemID=0100-50-... TTFN
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> TK!Solver is probably the closest thing to what you apparently want:
Yet does not meet the requirement: a spreadsheet program.
> you are out of luck
So it seems! Thanks, all. |
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IRstuff (Aerospace) |
25 Jul 12 15:23 |
I would argue, however, that TK Solver IS A spreadsheet program, since its inputs are all entered in a table format. It may not be what you want, but it is a form of a spreadsheet program, since everything is entered into tabular sheets. TTFN
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IDS (Civil/Environmental) |
25 Jul 12 16:47 |
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Just the basic spreadsheet program features e.g. of Excel, plus the units as described. |
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IDS (Civil/Environmental) |
25 Jul 12 17:09 |
Quote:Just the basic spreadsheet program features e.g. of Excel, plus the units as described.
OK, the feature you wanted is a little harder than I first thought, but it should be doable.
But I must say that converting values to/from one specified system of units from/to another specified system of units (or base SI units) seems to me like the basic functionality needed in a "units aware" spreadsheet, and that's what my spreadsheet does. Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
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> OK, the feature you wanted is a little harder than I first thought, but it should be doable.
That would be great.
> But I must say that converting values to/from one specified system of units from/to another
> specified system of units (or base SI units) seems to me like the basic functionality needed
> in a "units aware" spreadsheet
Agreed. I accept I am asking for more than basic.
You asked: Anything else you would like? My answer: no - that's all I am missing. |
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IDS (Civil/Environmental) |
25 Jul 12 18:43 |
Quote:You asked: Anything else you would like? My answer: no - that's all I am missing.
OK, I should have something presentable within a few days (depending on time required for paid work :)) Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
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IDS (Civil/Environmental) |
31 Jul 12 0:09 |
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IDS (Civil/Environmental) |
31 Jul 12 4:08 |
I've made a couple of changes to the spreadsheet:
- Since the OP specifically mentioned specific heat, I have added specific heat units (SI only at the moment).
- When no output units are specified the function generates a result value and units. Previously these were discarded if the output units were not recognised, but the value will be valid so I have changed it so that the value and units are returned as long as all the input units are recognised.
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
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Doug, in your spreadsheet are not included units of Decimal Metric System, anywhere a good work, Felicidades¡¡ |
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IDS (Civil/Environmental) |
31 Jul 12 18:56 |
surfer200 - I'm not sure what you mean by the Decimal Metric System, but it should recognise any metric unit with any of the recognised prefixes.
Can you give an example of something that doesn't work? Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
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Doug: kg/cm2, ton/m2, kg/m3--- etc |
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In the specific heat example, while J and kJ work as an output unit, e, Wh, BTU do not seem to work. It seems to accept BTU as an input unit, and the return unit not specified appears to do the conversion correctly, but when I put BTU.kg-1.K-1 in H53, it claims to not be able find a "To" unit. TTFN
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IDS (Civil/Environmental) |
1 Aug 12 20:11 |
surfer200 & IRstuff - there is a similar problem in both cases with non-SI compound return units. The program can handle input made up of any combination of recognised input units (including kg, kgf, and m with any prefix), but if these combine to make a unit that is not in the list it can't break down the compound non-SI units into their constituent parts. The solution is to add more units to the non-SI list.
For stressess I will certainly add kgf/cm2, kgf/m2, and also kgf.cm and kgf.m for moments. At the moment I don't intend to add ton/m2 and ton.m because of the numerous different "ton" definitions. Note that the "tonne" (1000 kg) is already listed as a unit of mass, but a tonne.m will not be a recognised unit of bending moment, so you won't be able to convert lbf ft to tonne.m, but you will be able to go from lbf ft to kgf.cm.
For specific heat I will add common non-SI units to the list, but they won't include BTU.kg-1.K-1 or other mixed systems (unless there are examples of mixed units in common use).
Regardless of what I add to the list, it is editable, so people can add whatever they like. I'll describe the procedure for doing that in my next blog post on the units topic.
Thanks for the feedback. Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
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IDS (Civil/Environmental) |
2 Aug 12 1:30 |
Quote:My weapon of choice is still Mathcad.
That's OK, I'm not aiming to take over the Mathcad market.
Not just yet anyway. :) Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
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IDS (Civil/Environmental) |
4 Aug 12 7:37 |
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IDS (Civil/Environmental) |
7 Aug 12 22:14 |
Whilst Modelica certainly looks interesting, the linked presentation says it is "a language for modeling of complex cyber physical systems i.e., Modelica is not a tool", so it doesn't seem to be what was asked for in the OP.
I was hoping I might get some feedback on my spreadsheet:
- Does it do what was wanted?
- If not, what is lacking?
- Any other comments? Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
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"Modelica," in the abstract, is indeed only the specification for the language. However, there are at least 4 different implementations of Modelica, of which, OpenModelica is an open-source and free implementation. OpenModelica's install file is about 350MB, so not a tool for the faint of heart or short of memory. TTFN
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IDS (Civil/Environmental) |
9 Aug 12 22:45 |
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IDS (Civil/Environmental) |
30 Aug 12 3:37 |
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DSikes (Mechanical) |
21 Sep 12 18:33 |
I just downloaded the latest version of the spreadsheet and I am having issues with the evalu function. It says that N is not a compatible unit but when I leave off a set unit it gives kg.m.s-2 which = N. I can use the convertA function to then convert the result of evalu which correctly gives N as the units though. I tried with both the spreadsheet and the add-in and had the same issue with both.
Thanks,
Daniel |
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IDS (Civil/Environmental) |
21 Sep 12 18:58 |
Quote:I just downloaded the latest version of the spreadsheet and I am having issues with the evalu function. It says that N is not a compatible unit but when I leave off a set unit it gives kg.m.s-2 which = N. I can use the convertA function to then convert the result of evalu which correctly gives N as the units though. I tried with both the spreadsheet and the add-in and had the same issue with both.
I'll have a look. Could you post the actual example you are having the problem with? Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
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IDS (Civil/Environmental) |
21 Sep 12 22:14 |
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DSikes (Mechanical) |
22 Sep 12 10:05 |
I downloaded the updated version and N seems to be working fine now. However, I'm now having an issue with Pa. It is giving the same units not compatible message that N was. I've attached the sheet that I was using (I was testing on the EvalU tab near the bottom). Great work on this spreadsheet though, probably the most useful add-in that I've come across.
Thanks,
Daniel |
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IDS (Civil/Environmental) |
22 Sep 12 19:35 |
Daniel - thanks for the comments and the feedback.
The problem with Pa was I had it defined in the table as m-2.N, rather than N.m-2. I forget why I did that, but I suspect it was a workaround for N not working properly, which stopped working when N was fixed. Anyway, now both N and Pa seem to work OK, both with other SI units and non-SI units.
One thing that still doesn't work as well as I would like is that it doesn't recognise N.m as being equivalent to J. The problem is that the way it is set up at the moment I can't specify N.m as being both a bending moment or torque and energy. I'll see if I can fix that in the next version.
Download as before: http://www.interactiveds.com.au/software/Units4Exc...
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
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sibeen (Electrical) |
24 Sep 12 6:24 |
Rev, nice to see that furlong per fortnight made the list :) |
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DSikes (Mechanical) |
24 Sep 12 12:13 |
I downloaded the latest version and am still having the same issue with Pa. It says that Pa is not a compatible unit with kg.m-1.s-2. Could it be that since the calculation doesn't involve N directly that it doesn't recognize that it is also equivalent to N.m-2?
Thanks,
Daniel |
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IDS (Civil/Environmental) |
25 Sep 12 7:39 |
Daniel - Now fixed so that Pa, N.m-2 and kg.m-1.s-2 will all be recognised as the same thing. I have copied the updated .xlsb version to the download site. I'll upload the add-in version in the next few days. Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
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Aibase is also a Windows program which can calculate with SI-unit expressions:
http://www.aibase-cs.com/quantities.html
It's not a true spreadsheet program, because calculations are based on script, and version 3 has no functions to create large tables. It might be of interest though if not an office-like spreadsheet is required, but free-form documents with calculations. |
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I would recommend TechCalc100 found on Amazon.
It is a very practical Excel Technical Calculation Tool that requires no iteration, formulation, isolating variables, re-writing equations and replacing unknown variables. |
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