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dbauer1-Visitor
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August 8, 2016
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Units in roman

  • August 8, 2016
  • 8 replies
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Units in roman

I challenge anyone to find a scientific paper or a book in any science or engineering discipline, published by a reputable company, in which units are shown in italics. Please let me know if you find one! In state-of-the-art publishing, units are printed in roman (upright and not bold).

“The International System of Units”, now adopted throughout the world, specifies which units to use and how to write them. Defined in the SI Brochure , it is clear on the subject:

Chapter 5: Writing unit symbols and names, and expressing the values of quantities

Unit symbols

Unit symbols are printed in roman (upright) type regardless of the type used in the surrounding text. They are printed in lower-case letters unless they are derived from a proper name, in which case the first letter is a capital letter.

The National Institute of Standards and Technology (NIST), an agency of the U.S. Department of Commerce, has published “The NIST Guide for the use of the International System of Units”, which is also clear on the subject:

Chapter 6. Rules and Style Conventions for Printing and Using Units

6.1.1 Typeface

Unit symbols are printed in roman (upright) type regardless of the type used in the surrounding text. (See also Sec. 10.2 and Secs. 10.2.1 to 10.2.4.)

where Sections 10.2 and 10.2.1 to 10.2.4 restate and explain the rule.

Essentially, units are written in roman in order to distinguish them from variables which are written in italics. For example, "m" is a variable whereas "m" is a unit. Please refer to one of the above publications for more details. Note that the color of the font for units (as well as for numbers, variables, etc.) is not addressed in these documents..

In Mathcad, displaying units in a color different than that of variables is a good way to distinguish them even better. However, displaying them in italics is unnecessary and wrong.

Mathcad default setting

All the marketing for PTC Mathcad is done with the units shown in bold blue jazzy italics and the product is delivered with this font set by default.

When asked why the default font for units is such, PTC Mathcad dodges the question by saying that, in Mathcad, names of units are treated as variables, so if variables are in italics so should be the units, and that anyways users can easily change the font for units.

The problem

The problem is that my students, who use Mathcad, could think that the default font for units is correct, whereas actually it is wrong and unacceptable.

I have to ask my students to change the font to roman. If they ask me, I can only explain to them that the funny default font was probably a request from the company’s marketing department.

Correcting the situation

There are laws behind the recommended use of the SI units in the U.S. and other countries around the world. Standards are intended to ensure public safety and to improve efficiency in commerce, heath system and teaching. Non-compliance can result in large economic losses. Students are entitled to be taught properly. A court could consider that PTC Mathcad has mislead its users, thousands of students and companies, in thinking that the proper font for units is italics.

While a lawsuit against PTC Mathcad is unlikely, but possible, the company should set a good example and correct the situation by doing the following:

  1. Clarify the distinction between fonts for units and for variables.
  2. Change the factory default setting of the font for units to roman (upright and not bold). Colors are fine.
  3. Modify all advertising to show units in the way described above.
  4. Publish a white paper announcing the change and saying how great the company is for complying with state-of-the-art publishing and the worldwide SI standard.

References

The “SI Brochure” is available in English at http://www.bipm.org/en/publications/si-brochure/.

“The NIST Guide for the use of the International System of Units” is available at http://www.nist.gov/pml/pubs/sp811/.

    Best answer by dbauer

    the chance that a lawsuit would go anywhere is nil.

    You never know what a court would decide.

    PTC has not mislead anyone

    Rephrase if you like to read "Because the default font for units is italics, users delude themselves into thinking that the proper font for units is italics."

    they have not claimed that their font for units complies with any particular standard.

    Well,

    it would be better if Mathcad adhered to recognized standards

    and then they could claim that they do.

    8 replies

    S
    StuartBruff23-Emerald V
    23-Emerald V
    August 8, 2016

    Agreed.

    You could also add the ISO 80000-1 (Quantities and Units - Part 1: General), which probably takes precedence over the NIST Guide in most countries (I note that the given version of sp811 is dated 2008, and still refers primarily to the ISO 31 series, which the ISO 80000 series replaces).

    Stuart

      F
      Fred_Kohlhepp23-Emerald I
      23-Emerald I
      August 8, 2016

      I understand your concerns.  Please emphasize this point to your students, and require them to adjust their Mathcad documents to correct the problem.

      But note that they can adjust Mathcad to correct this problem.

      With all that's deficient in the newer versions of Mathcad (which is still a large step backwards from the capabilities in version 15), please don't ask PTC to divert effort to fixing this problem.

      This is an opportunity for your students to learn a valuable life lesson:  Sometimes you must rework the tool to do what you need.  (You can find, in this web site, a long running discussion about showing the equation, then the equation with values, then the final answer.  And you can track the torturous path thru the years while we tried to enable this.  Mathcad 15 can come closer than Prime, but it still is an elusive goal.  And more teaching professionals want to see that from their students than are worried about the font choice for units.)

      Styles and standards change.  Perhaps we should petition the standard writers to require units be in italics, bold, and blue.  😉

        S
        StuartBruff23-Emerald V
        23-Emerald V
        August 8, 2016

        Fred Kohlhepp wrote:

        I understand your concerns.  Please emphasize this point to your students, and require them to adjust their Mathcad documents to correct the problem.

        But note that they can adjust Mathcad to correct this problem.

        With all that's deficient in the newer versions of Mathcad (which is still a large step backwards from the capabilities in version 15), please don't ask PTC to divert effort to fixing this problem.

        This is an opportunity for your students to learn a valuable life lesson:  Sometimes you must rework the tool to do what you need.  (You can find, in this web site, a long running discussion about showing the equation, then the equation with values, then the final answer.  And you can track the torturous path thru the years while we tried to enable this.  Mathcad 15 can come closer than Prime, but it still is an elusive goal.  And more teaching professionals want to see that from their students than are worried about the font choice for units.)

        Styles and standards change.  Perhaps we should petition the standard writers to require units be in italics, bold, and blue.  😉

        If it were a complicated change, I might agree that it should be low on the priority list.  However, as one of Mathcad's major selling points is its unit handling and the changes are simple enough that they shouldn't take even a summer intern too long to design, implement and document, PTC really ought to get it right for the next major release at the very least.

        Styles and standards change. 

        True, but these particular standards have been around a long time (decades) and are fairly well entrenched in the scientific domain.   If they change, then it will only likely be after an extensive consultation period and with several years warning.  This should give some opportunity for people to postpone learning their valuable life lesson 😉

        Stuart

          R
          RichardJ19-Tanzanite
          19-Tanzanite
          August 8, 2016

          I agree that it would be better if Mathcad adhered to recognized standards, but the chance that a lawsuit would go anywhere is nil. PTC has not mislead anyone, because (as far as I know) they have not claimed that their font for units complies with any particular standard.

          D
          dbauer1-VisitorAuthorAnswer
          1-Visitor
          August 8, 2016

          the chance that a lawsuit would go anywhere is nil.

          You never know what a court would decide.

          PTC has not mislead anyone

          Rephrase if you like to read "Because the default font for units is italics, users delude themselves into thinking that the proper font for units is italics."

          they have not claimed that their font for units complies with any particular standard.

          Well,

          it would be better if Mathcad adhered to recognized standards

          and then they could claim that they do.

          R
          RichardJ19-Tanzanite
          19-Tanzanite
          August 9, 2016

          the chance that a lawsuit would go anywhere is nil.

          You never know what a court would decide.

          I am not a lawyer, but in very obvious cases such as this even if I can't know what a court would decide then I can know what is likely that it would decide. If you prefer, "the chance that a lawsuit would go anywhere is miniscule"

          PTC has not mislead anyone

          Rephrase if you like to read "Because the default font for units is italics, users delude themselves into thinking that the proper font for units is italics."

          Rephrase it any way you wish, as long as it's accurate. The key point in your new version is that "users delude themselves". PTC has not claimed that the font they use conforms with any particular standard, so if users "delude themselves" into thinking it represents some standard then that is the user's problem, not PTC's.

          There are other standards for math notation that PTC does not conform to (e.g. notation for scalars vs vectors vs matrices). Also standards for physics, chemistry, engineering, etc. There is no law that requires them to conform to such standards, so as long as they do not claim that they do, you have no case.

          V
          ValeryOchkov24-Ruby IV
          24-Ruby IV
          August 9, 2016

          I must use in Russian books and articles a roman font if C (or others letter) is a Russian letter as variable and an italic font if C is a Latin one.But now this rule is not so hard.

          V
          ValeryOchkov24-Ruby IV
          24-Ruby IV
          August 9, 2016

          In some math (old) articles and books a roman font points scalars but an italic one - vectors.

          D
          dbauer1-VisitorAuthor
          1-Visitor
          August 10, 2016

          From the first volumes of the Transactions of the American Society of Civil Engineers (just an example), units have been printed in roman. The following excerpt is taken from Volume 2, published in 1874:

          Image1.jpg

          You will notice that:

          • pound units (lbs) are typed in roman. (Units are in roman throughout the Transactions)

          At the same time, notice that:

          • intermediate numerical values are shown;
          • variables are not unnecessarily repeated in the second equation; (u⁴ is a typo, it should read u₄)
          • the symbol for multiplication is ・ when used with variables and ✕ when used with numbers.

          The last point is mentioned, 142 years later, in the current International System of Units:

          Image2.png

          In the year 1900, Gustave Eiffel published a voluminous book describing the main structural and mechanical aspects of design, construction and operation of the Eiffel Tower. Here is where it gets crazy. Units are printed in italics both in the text and in calculations!

          Image3.png
                                                  Image4.png

          Wow! At least, I won my own challenge and please don’t tell me that Eiffel did not know what is was doing.

          But today units must be printed in roman. It all about standards and legislation. At first, governments are expecting that the changeover to SI will be done on a voluntary basis. Eventually though, companies that do not abide by the law may be subject to fines. Boards of Professional Engineers may not appreciate the fact that engineers do not document their work in the most appropriate way. The ISO certification of some engineering firms could be jeopardized. Who knows, but then you will be arguing with these people, not with me.

          R
          RichardJ19-Tanzanite
          19-Tanzanite
          August 10, 2016

          then you will be arguing with these people, not with me.

          Aside from the question of whether PTC could be realistically sued over this, who is arguing with you?

          D
          dbauer1-VisitorAuthor
          1-Visitor
          August 10, 2016

          Sorry if I "mislead you" into thinking that the purpose of my thread was to debate about lawsuits.

          Back to units:

          • If a sentence is in italics, like this one, it would make sense to have units in italics, for example 1 mm = 0.001 m.

          • Units could be in any font, for example 1 km = 1000 m, as long as it is that of the sentence.

          I found an occurrence of units in blue, bold, italics, in “Quotations of Brainy Smurf”:

          Image5.png

          V
          ValeryOchkov24-Ruby IV
          24-Ruby IV
          August 17, 2016

          In Russian the word  "roman" is not a font, but a literary work - роман, a novel - the novel of Leo Tolstoy's "War and Peace" for example.

          I read this discussion as a novel about units - the novel "Units general and in Mathcad partial". The chapter 1 "Angles and units: to be or not to be?"

            D
            dbauer1-VisitorAuthor
            1-Visitor
            August 19, 2016

            Hi Valery,

            Although the words have similar origin, i.e. "Rome" (Italy), "roman" is not as in "roman" (French) or роман (Russian). It is as in "romain" (French) and римский (Russian).

            A
            AlvaroDíaz12-Amethyst
            12-Amethyst
            August 19, 2016

            Hi Dominique.

            I don't have very clear this point.

            In spanish, "roman" means from Rome. But one "romana" means "steelyard", "romanitas" means flip flop sandals. And reversing Roma (Rome in spanish) we have amor (love)

            For the alphabet, this type of letter we call "letra de molde", which Google translates as "print": https://translate.google.com.mx/#es/en/letra%20de%20molde . This came from the old "tipos móviles", the letters which can be movables in the printing house (imprenta, in spanish). So, the other name in Spanish for this roman is "letra de imprenta".

            For the italics (Rome again?), in spanish we call this as bastardilla (yes, from bastard), cursiva or, some times, manuscrita (from mano = hand, escrita = wright).

            Best regards.

            Alvaro.

              D
              dbauer1-VisitorAuthor
              1-Visitor
              August 22, 2016

              Alvaro,

              You may want to refer to the Spanish translation made by the Centro Español de Metrología (CEM):

              http://www.cem.es/content/sistema-internacional-de-unidades-si-8ª-edición-2006-español

              5.1    Símbolos de las unidades

              Los símbolos de las unidades se  imprimen  en  caracteres  romanos  (rectos), independientemente del tipo de letra empleada en el  texto  adyacente...

              5.3.1   Valor y  valor numérico de una  magnitud; cálculo de magnitudes

              Los  símbolos  de las magnitudes están formados generalmente por una sola letra en cursiva...

              S
              StuartBruff23-Emerald V
              23-Emerald V
              August 23, 2016
              Dominique Bauer wrote:

              Units in roman

              “The International System of Units”, now adopted throughout the world, specifies which units to use and how to write them. Defined in the SI Brochure , it is clear on the subject:

              Chapter 5: Writing unit symbols and names, and expressing the values of quantities

              Unit symbols

              Unit symbols are printed in roman (upright) type regardless of the type used in the surrounding text. They are printed in lower-case letters unless they are derived from a proper name, in which case the first letter is a capital letter.

              The National Institute of Standards and Technology (NIST), an agency of the U.S. Department of Commerce, has published “The NIST Guide for the use of the International System of Units”, which is also clear on the subject:

              Chapter 6. Rules and Style Conventions for Printing and Using Units

              6.1.1 Typeface

              Unit symbols are printed in roman (upright) type regardless of the type used in the surrounding text. (See also Sec. 10.2 and Secs. 10.2.1 to 10.2.4.)

              where Sections 10.2 and 10.2.1 to 10.2.4 restate and explain the rule.

              Essentially, units are written in roman in order to distinguish them from variables which are written in italics. For example, "m" is a variable whereas "m" is a unit. Please refer to one of the above publications for more details. Note that the color of the font for units (as well as for numbers, variables, etc.) is not addressed in these documents..

              In Mathcad, displaying units in a color different than that of variables is a good way to distinguish them even better. However, displaying them in italics is unnecessary and wrong.

              References

              The “SI Brochure” is available in English at http://www.bipm.org/en/publications/si-brochure/.

              “The NIST Guide for the use of the International System of Units” is available at http://www.nist.gov/pml/pubs/sp811/.

              Here's another item from NIST:

              Typefaces for Symbols in Scientific Manuscripts

              Terms & ConditionsAccessibility statement