How are
formulae to be drafted?
Even though
this depends largely on the software you will use, here are two main Word
applications for this:
- Through the “Math Type” application, which
we CCMC editors use and recommend greatly; this function allows us to create
formulae from scratch and to change or correct them quite easily.
If you create a formula with Math
Type , all you will need to do is: go on the “Math Type” menu, click on “Inline”
and use the various drop-down menus; if you need to correct it afterwards,
click right on it and select "Open":
- Through the “Word Equation Editor”
application, depending on the version of Word you will use.
"Formula"
or "equation"?In accordance with the latest edition of the Internal Regulations Part 3, the preferred term is "formula", and not "equation", which is why it is now used systematically in all CCMC deliverables.
A few
remarks regarding the numbering and layout of formulae:
According
to the Internal Regulations Part 3
(6.6.10.3), "if it is necessary to number some or all of the formulae in a
document in order to facilitate cross-reference, Arabic numbers in parentheses shall
be used, beginning with 1". Furthermore, if the formula appears in an
annex, the number between brackets shall be preceded with the capital letter of
the annex followed with a full stop (for instance, "(A.1)" or
(C.23)").
Apart from
the latter case, the numbering of the formulae is to be completely independent from
that of the clauses and subclauses, tables and figures in the same document.
A formula
is always preceded with a space (through tabulation) and its corresponding
number between brackets is aligned on the right.
Here is an
example for the layout of formulae:
What does
a formula key look like?
As shown in
the example given just above, a key to a formula is not always necessary when
all the symbols given in it are explained and/or defined in the rest of the
text above it.
If a key is
given, it should consist in a series of defined symbols, each of which is
preceded with a space, and which is introduced with "Where"; see the
following example:
Regarding
the decimal sign, multiplication signs and numbers that are composed with more
than three digits:
The only decimal sign allowed in CCMC deliverables is a
comma (Internal Regulations Part 3,
6.6.8.1).
Please also
be aware of the following issue regarding multiplication signs: "The
multiplication cross (×) shall be used to indicate the multiplication of
numbers and numerical values written in decimal form, in vector products and in
cartesian products. The half-high dot (·) shall be used to indicate a scalar
product of vectors and comparable cases." (Internal Regulations Part 3, 6.6.8.4)
Finally,
the Internal Regulations Part 3
(6.6.8.3) makes it clear that each group of three digits contained in a number
shall be separated with a space, either before or after a decimal sign (for
example, "0,002 5", "2 251,536 75").Any questions? Any related difficulty? Please drop us a comment by clicking on the button below!
Next week: Everything you always wanted to know about Symbols & Abbreviations, but were too afraid to ask!
Frédéric
Dufour (fdufour@cencenelec.eu)
© All CCMC posted information
is copyrighted by CEN and/or CENELEC. Extracts may be used providing that
the source is mentioned.
Please note that the CCMC
posted information is drawn from a variety of sources already publicly
available on the CEN and CENELEC websites.
Dear Mr Dufour,
ReplyDeleteThanks for your helpful article in the Editors´Blog – it is very helpful to get some examples!
I still have an open question that I would like to rise. I´m unsure in which way the definition of units should be done. Could you give an advise which is the preferred way?
Thanks a lot!!
Best regards
Torsten Hildebrandt
Dear Mr Hildebrandt,
DeleteMany thanks for your interest in our blog! Your e-mail shows us how this has become “alive” and how our contributions to it are so well followed.
In the Internal Regulations – Part 3, there is no definite rule as to how units are best indicated for formulae. Yet here are two suggestions, the first one of which stems from the Internal Regulations – Part 3 (even though this is no absolute requirement):
- Units may be indicated in the clause or subclause dedicated to “Terms and definitions and/or symbols and abbreviations”. Thus each unit can be indicated on the same line as its related symbol or abbreviation.
- If this is not feasible, the best option from a practical viewpoint would consist in adding a key after each formula (that would be introduced with "where") in which the symbols in it would be defined and/or the related units could be indicated. (If the unit concerns the symbol which is calculated by the formula, it is possible to indicate the unit between brackets in the paragraph just above.
One golden rule which is mentioned in our blog: if the unit follows a number directly, then use its abbreviated form (for instance, “5 mg”). (If the unit is mentioned in a paragraph, though without following a digit, you may use its unabbreviated form.)
Sincerely,
Frédéric Dufour