@Szabolcs I think it might get overridden by PageBreakWithin but can't remember

The whole PageBreak... mechanism is super buggy

@Szabolcs You should have used Latex. For adding Latex notations on Mathematica plots, I recommend a package called MaTeX. ;) I used Mathematica once for final school report and that was it. It does take a little extra work to use Latex, but at the end, it is well worth it.

@Szabolcs What is the requirement? Do you need no-pagebreak between figure and figure caption?

@Nasser I was using texlive, but it's too huge, and I don't have the needs of writing articles in PDF format. So now I'm exploring this solution: KaTeX/mathjax => SVG => M's Graphics.

@Silvia I use tex4ht to convert latex to HTML. All of my site is written in Latex and converted to HTML like this. In addition, if you have source in Latex you get PDF files as well. I also use mathjax for math on the web, since tex4ht uses mathjax for HTML as an option. I do not know what you mean by texlive is too large? once you install it once, that is it.

@Nasser I run katex in local browser, using websocket to launch js execution from M side and read the SVG result out. Then I have a script in M to parse SVG to Graphics.

The result would be like this.

KaTeX and websocket are both super fast.

@Nasser I'm not working in academy, so I don't have the needs of providing PDF format to others. Texlive for me will be only a tool for formula in plots & graphics, so the harddisk space it takes is too much for me.

@Silvia but PDF is universal. If you do not have PDF, what do you use for your documents? i.e. how do you save your documents as?

@Nasser Sorry my mistake. I do provide PDF to clients. But they are mostly documents with UML diagrams or API descriptions. Latex is not the best tool for them. So I usually make the document in specific editors (like Visio or yEd) then generate PDF with virtual printer.

@Silvia I do not use UML, but there are packages for it in Latex, please see tex.stackexchange.com/questions/875/… but whatever works for your needs is best. For simple diagrams in Latex, I use IPE, which is easy to use and allows direct Latex to be typed on the diagram. Ofcourse, I use Mathematica for all plots and animations.

@Nasser Yes I know there are latex packages for UML, but it's handy to draw directly on canvas. We are even exploring the possibility of drawing on real paper, then scan and OCR to digital version.

@Szabolcs I propose to change the title of this question. We verified that this is also an issue on Linux and Windows.

in case anyone missed it, the VideoPlay crash was recently fixed via paclet update, mathematica.stackexchange.com/a/216628/1601

Seeing this a lot more in 12.1...

@halirutan @Szabolcs On Windows with the Covid19 dataset here is the performance I'm seeing. I see most of the delays you mention, but scrolling and editing text don't seem too bad.

@MichaelHale Can you try my make-it-burn-baby example?

head = CharacterRange["A", "E"];
ip[] := ListInterpolation /@ RandomReal[{-1, 1}, {Length[head], 10}];
ds = Dataset@Table[Inner[Rule, head, ip[], Association], {40}]

Sure. Have noticed about a half second delay a lot of times when the function name autocompletion list pops up that I don't recall as much from 12.0.

Also, can you ensure that you have a regularly sized notebook, so that the dataset does not entirely fit in width.

Definitely takes it a while. But does seem to eventually stabilize with fast scrolling and typing. Until another mouse over event is triggered it seems. Then it freezes for a few seconds, then gets fast again, etc.

I do some horizontal scrolling at end.

On the flip side the 3D stuff is a lot faster now.

This is a default high end Dell XPS laptop I bought last January.

@MichaelHale The stabilizing until another hover thing happens for me too. Do you notice a difference between having the notebook enlarged so that the whole DS is visible?

For me, it is somewhat faster then.

Yes that does help. The hiccups occur at the same frequency but only last 1-1.5 seconds instead of 3-4+.

So I'm guessing the hover events are always triggering a re-layout calculation, the duration of which is affected by window size, types of data displayed, etc.

If it's anything more complex than an insert cell above/below operation.

@MichaelHale I really hope I'm wrong here, but I believe this will be an awful thing to fix. Worst case: They just pushed more and more dynamic stuff in there until finally, the lags become very noticeable.

@halirutan I would guess, based on what I saw in the streams, that they've got a bunch of styling that looks at something like the CodeHints. That'll be nasty to get performing even okay.

@MichaelHale Try this: Import["https://covid.ourworldindata.org/data/ecdc/total_cases.csv", "Dataset", HeaderLines -> 1]

I can barely type into the original input cell when the output is shown. Bringing the notebook to the forewground takes at least a full second. Horizontal scrolling locks up the FE temporarily.

I'm curious why SW didn't see this though

12.0 works fine. Not great, but I can Command-Tab easily and I can type into the input cell without delay

I wonder was it a last-minute addition after the last stuff he saw. I definitely remember a stream where they were looking at the new Dataset stuff

Here's one youtube.com/watch?v=EPZ1yFSURgA

@Szabolcs Yep, that one's pretty bad. Hover/scroll hiccups are back to 4+ seconds. Going to next page of results 10-15 seconds. Modifying the input code is big delay pretty much every keystroke.

Just string and number data, but lots of columns are causing the problem I guess.

@CarlLange The much bigger problem is imo: The QA team should have cried "full stop" long time ago. This is their job.

@halirutan Oh, completely. I'm just wondering was it so last minute a change that it bypassed QA.

@CarlLange No. I already reported this in 2019 in the pre-release.

@halirutan Fair enough. I really hope 12.1.1 gets shipped ASAP to fix this. Nearly all of my notebooks use Dataset somewhere

@CarlLange Do you have a mail address?

@halirutan This comes back to the fact that the company lost concept of what suitability for real work means a long time ago. They only check things on toy-size examples, almost never on real-world tasks. Most people posting on Community are hobbyists. These coronavirus datasets are also tiny, toy-size things ... but now we got to the point that even these cannot be handled.

@Szabolcs The sad thing is, strip all the shiny front end stuff away, and you still have a powerful computation kernel. You might need to deal with Dates yourself or use a custom CVS import, but you had a clean language with a lot of symbolic power.

@halirutan Yup! Uncompress["1:eJxTTMoPCuZhYGBITizKcUjLSazQy0wFADydBi0="]

Unfortunately I was also in the prerelease, but I've been quite busy with non-WL related things so I didn't have much time to play around with it :(

@halirutan @Szabolcs I report a FE hang that forces me to force-kill Mathematica at least once a week when I'm actually doing work in Mathematica. The kernel can handle the data, if I write the code correctly, but the FE is unbearable.

I always have to remind myself to not let the FE try to render anything until I absolutely need it and even then sometimes I still get hangs

@Kuba did you know about this: mathematica.stackexchange.com/a/216810/38205