DrClaude said: Do you mean

$$

\int x \, \mathrm{d}x

$$

as opposed to

$$

\int x \, dx

$$

?



There is no accepted standard for this, since while many (including me) argue that the former is the proper way to typeset the d, Physical Review uses the latter.

Code: bla bla bla *Equation/Figure code* bla bla bla

Code: bla bla bla % *Equation/Figure code* % bla bla bla

This one I don't really care about as long as it is done consistently. What I do care about is when it is used with improper spacing so that it is not clear at all what is there...$$\int x dx$$Note that the LaTeX code has the required space, but a space in math mode in LaTeX is not what many people think it is.Here is a selection of my LaTeX pet peeves. I don't think it is exhaustive but those are the ones I can think of at the moment.A common mistake is to want to space out the LaTeX source around a figure or equation. What many do not realise is that if this is done carelessly, LaTeX is going to interpret this as the equation/figure forming its own paragraph due to the multiple line breaks in the source. This can be helped in the following fashion by commenting out the line breaks:Incorrect:Correct:Sure, there are some times when you might want to actually end your paragraph with an equation, then go ahead. However, this should be done consciously, not by accident.Yes, those dollar signs are annoying to type out, but not including them is a certain way to make sure your report looks unprofessional. It is ugly and confusing and some symbols really look different in regular text and in the math mode italic.Incorrect:Einstein found out that$$E = mc^2,$$where E is the energy, m is the mass, and c is the speed of light in vacuum.Correct:Einstein found out that$$E = mc^2,$$where ##E## is the energy, ##m## is the mass, and ##c## is the speed of light in vacuum.It has already been mentioned in this thread. In particular the bra-kets used in quantum mechanics. < and > in LaTeX are relations and are typset as such, with spacings appropriate for relations, such as ##1 < 2##. This is not to be used for bras or kets ##|1> |2>## (note the horrible spacing - this is practically unreadable to me without getting a headache). The appropriate delimiters to use in this case are \langle and \rangle, ##|1\rangle## or ##\langle 2|##. Alternatively, < and > do become delimiters when used in conjunction with \left and \right.My PhD student thinks I have an uncanny sense for this one when correcting texts. LaTeX interprets periods as the end of a sentence and typsets the spacing accordingly, slightly longer than the spacing between words. However, LaTeX does not inherently know when your period is just the period noting an abbreviation such as e.g., i.e., etc. (Note that the period at the end of etc. is serving double duty as a period in that sentence! Do not double period abbreviations at the end of a sentence.) This can be corrected by telling LaTeX to use the appropriate spacing explicitly. A regular spacing is just a backslash followed by whitespace (\ )."Fig.3". LaTeX does not know that your space after Fig. is not just a regular space where it can line break at will. Tell it that you will have none of it by using a non-breaking space (~). This goes for things like equation numbers (Eq. (3)), figure numbers (Fig. 4), or units (241 kg).1.23cm versus 1.23 cm. The appropriate typesetting is with a space. Also see the previous point not to mess up the line breaks!Units are not mathematical symbols. Do not typeset them as such. In running text, do not even enter math mode if you are just writing a number. End math mode after the number if it is part of an equation: ##\ell = 2.32## cm. (Don't forget the non-breaking space between ending math mode and the unit!) Inside a displayed equation, use a ~ to get the appropriate spacing and then use an \mbox or \rm for the units. Do not forget to separate units by a small space:$$100~\mbox{kgm/s} \quad \mbox{vs} \quad 100~\mbox{kg}\,\mbox{m/s} \quad \mbox{or} \quad 100~\mbox{kg m/s}$$(preferably the middle one).Put the ##\circ## in the correct place. This includes not putting it at all when you are using Kelvin as your temperature unit. Wrong:$$90^\circ\mbox{C},\ 45^\circ~\mbox{C},\ 30~^\circ\mbox{K}$$(The middle one technically says "45 angular degrees Coulomb" ...)Correct:$$90~^\circ\mbox{C},\ 30~\mbox{K}$$Sure, you want to write the x-y-plane and you want to follow the rule that x and y need to be typeset in math mode, but for Heaven's sake, typeset the dash in between in regular text or it becomes a minus sign (which is also an operator and will be typeset as such with the spacings appropriate for that). Compare:$$\mbox{$x-y$-plane} \quad \mbox{to} \quad \mbox{$x$-$y$-plane.}$$(Or consistently use ##xy##-plane instead ...)Also double check your usage of dashes (-) versus N-dashes (--) and M-dashes (---) and use the appropriate ones. For example, typically double names in things that are named after people in sciences (e.g., Levi-Civita) are separated by a regular dash whereas multiple different names (e.g., Robertson-Walker) would be separated by an N-dash. (My proof-reader thought Levi-Civita should go with an N-dash and consistently marked this, I told him otherwise.)Most math environments have a particular way in which they need to be used in order to get the appropriate spacing.\begin{align*}E = &B(a+b)\end{align*}Note how the = is closer to the ##B## than to the ##E##. This is not correct spacing.In particular those where your equations overflow to the point of overwriting the equation number. Youline break an equation!Need I say more? A few pts, fine. But if your hboxes overflow by 234 pts it is going to look awful ...Just don't.Well, I don't think it is exhaustive but I am getting tired ...