- #1

TRB8985

- 74

- 15

- TL;DR Summary
- Clarification on subscripts involving axes and whether they should be italicized.

Good afternoon,

I have a question about italicizing certain subscripts. Say we have the following kinematic equation:

$$ y_{i} = y_{f} + v_{i_y}t + \dfrac{1}{2}a_{y}t^2$$ Where the ##i## and ##f## subscripts are in reference to initial and final displacements, and the ##y## subscript is in reference to an acceleration along the y-axis.

In the sources I've seen from NIST, IUPAC, and others##^{1, 2, 3, 4, 5}##, the general standard seems to be that

In this situation, the y-axis (in whichever direction we have chosen it to be), does not change. Furthermore, the vertical acceleration in this simple example does not change, either. (9.80 m/s²)

Thus, I'm under the impression that the subscript ##y## would be upright as well. However, at the bottom of the first page in the typefaces document from NIST, I can see they're italicizing the z-coordinate in ##\omega_{z}##. It's not entirely clear if this coordinate is italicized due to the value of ##\omega## changing as one moves along the z-axis, or if this references the z-axis itself. Hence, my confusion.

Is anyone familiar with such an example and know the correct way in which this should be expressed? Thanks!##^{[1]}## Hughes, K. 2016 May 4. To italicise or not to italicize. Brushing Up Science. https://brushingupscience.com/2016/05/04/to-italicise-or-not-to-italicise/

##^{[2]}## Vrijmoet, E. 2017 May 1. Eliot's LaTeX Notes for Science Writing. Georgia State University. http://astro.gsu.edu/~vrijmoet/latexnotes.html

##^{[3]}## Boffin. 2011 Oct 30. Should subscripts in math mode be upright? Stack Exchange. https://tex.stackexchange.com/questions/33120/should-subscripts-in-math-mode-be-upright

##^{[4]}## Beccari, Claudio. 1997. Typesettings mathematics for science and technology according to IOS 31/XI. TUGboat. 18(1). https://tug.org/tugboat/tb18-1/tb54becc.pdf

##^{[5]}## Keramati, H. 2020 July 7. When to italicize in a math expression? LinkedIn. https://www.linkedin.com/pulse/when-italicize-math-expression-hamed-keramati/

I have a question about italicizing certain subscripts. Say we have the following kinematic equation:

$$ y_{i} = y_{f} + v_{i_y}t + \dfrac{1}{2}a_{y}t^2$$ Where the ##i## and ##f## subscripts are in reference to initial and final displacements, and the ##y## subscript is in reference to an acceleration along the y-axis.

In the sources I've seen from NIST, IUPAC, and others##^{1, 2, 3, 4, 5}##, the general standard seems to be that

**any italicized letter is a variable**. Thus, in the case above, ##i## and ##f## would not be italicized, as they represent*static*values of initial and final displacements. My question concerns ##y##.In this situation, the y-axis (in whichever direction we have chosen it to be), does not change. Furthermore, the vertical acceleration in this simple example does not change, either. (9.80 m/s²)

Thus, I'm under the impression that the subscript ##y## would be upright as well. However, at the bottom of the first page in the typefaces document from NIST, I can see they're italicizing the z-coordinate in ##\omega_{z}##. It's not entirely clear if this coordinate is italicized due to the value of ##\omega## changing as one moves along the z-axis, or if this references the z-axis itself. Hence, my confusion.

Is anyone familiar with such an example and know the correct way in which this should be expressed? Thanks!##^{[1]}## Hughes, K. 2016 May 4. To italicise or not to italicize. Brushing Up Science. https://brushingupscience.com/2016/05/04/to-italicise-or-not-to-italicise/

##^{[2]}## Vrijmoet, E. 2017 May 1. Eliot's LaTeX Notes for Science Writing. Georgia State University. http://astro.gsu.edu/~vrijmoet/latexnotes.html

##^{[3]}## Boffin. 2011 Oct 30. Should subscripts in math mode be upright? Stack Exchange. https://tex.stackexchange.com/questions/33120/should-subscripts-in-math-mode-be-upright

##^{[4]}## Beccari, Claudio. 1997. Typesettings mathematics for science and technology according to IOS 31/XI. TUGboat. 18(1). https://tug.org/tugboat/tb18-1/tb54becc.pdf

##^{[5]}## Keramati, H. 2020 July 7. When to italicize in a math expression? LinkedIn. https://www.linkedin.com/pulse/when-italicize-math-expression-hamed-keramati/

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