4 ms·
> Put a hook on the x to distinguish it from a times sign This is counterproductive IMO, because it makes it look like a chi. (The article notes the problem.)
by layer8 2y ago
> Put a hook on the x to distinguish it from a times sign
This is counterproductive IMO, because it makes it look like a chi. (The article notes the problem.) That seems more likely to cause issues than the possible ambiguity with the “times” symbol (“×”). If you need a multiplication symbol, use the middle dot (“·”) instead.
- lupire 2y agoThe article alludes to this when it mentions Calculus 3 (vector calculus): × is the cross product. • is the dot product. In dimensions higher than 1, they are different.
- RossBencina 2y agoI find it clearer to write dot products using inner product notation 〈,〉rather than \cdot .
- fifilura 2y agoIn Sweden, with scalars, we used vertically centered dot, but even that is pretty uncommon since most of the time, two letters or a letter and a number are mixed and then it is left it out altogether. This made the x problem much smaller.
- rossant 2y agoIn France we use the wedge ∧ for vector cross product.
- f1shy 2y agoSame in Spanish. That gets rid of the problem.
- SAI_Peregrinus 2y agoThen what do you use for the outer product?
- nxobject 2y agoI think the two example images are actually the same. (I've always done an italic X.)
- js8 2y agoIn the handwriting I learned, x had hooks on all four ends, while greek chi only on two. Anyway, I usually use simple cross as x, because it's only very rarely confused with cross product (and you can always parenthesize).
- caturopath 2y agoI make my x's with a backwards c and a c, like Computer Mondern and lots of fonts https://i.ibb.co/8LPsJKsj/image.png https://i.ibb.co/8LPsJKsj/image.png - doesn't look much like a chi or a times sign No one in the target audience is using × for scalar multiplication.
- brianstrimp 2y agoNot for scalar, but certainly for vector multiplication which a large part of the audience certainly needs a lot.
- TRiG_Ireland 2y agoMy x looks like a cross in normal handwriting, but like two back-to-back c's in algebra. I developed this habit very young, and have kept it.
- FungalRaincloud 2y agoI think it's important to consider audience. If I'm working with the intent that what I write is legible to folks who only have a basic understanding of math, I'll usually use the multiplication symbol (NOT the letter x, but ×, intentionally in the middle). Someone with more advanced knowledge of math, who may be more inclined to think it's an x, because my handwriting is shit, I will typically use the dot operator. But then there's the whole other audience where I need to define what the dot operator does. At that point, I'm probably pulling up something like LaTeX, because, again, my handwriting sucks. Funnily enough, when I write for the purpose of math, my numbers are more legible than when I just write down a number. For some reason, I code switch in my handwriting. Kinda obnoxious when I'm filling out forms.
- layer8 2y agoAudience is important. I'm not American and didn't learn the cross symbol for multiplication in school. We used the middle dot.
- TheRealPomax 2y agoI can't remember the last time I actually wrote a times sign.
- floodle 2y agoI did often in my degree, not for multiplication but the cross product
- TheRealPomax 2y agosure, but in that context there's no ambiguity (and technically, it's not the "times" symbol, that's the cross product symbol). We don't really use "x" in vector maths, it's all "a", "b", "v1", "v2", etc =) (at best you might use a .x subscript for 3D graphics but when did anyone ever do that by hand)
- patrick451 2y agoDepending on the context, dot and times may have different meanings.
- waynesonfire 2y agoi center the x times sign.