
Show HN: Mathcha – Online Mathematics Editor - buiducnha
https://www.mathcha.io/
======
jordigh
Nothing here attracts me away from pure LaTeX that much except two things: (1)
built-in symbol recognition (I still rely on
[http://detexify.kirelabs.org/symbols.html](http://detexify.kirelabs.org/symbols.html)
but it's rare for me to have to look something up) and (2) auto-resizing
delimiters.

Can any TeX experts explain to me why delimiters don't resize by default? Why
do we need to insert so many \left and \right commands?

~~~
beagle3
I am not an expert, but my impression was always that the way it is makes
things general, orthogonal, and easy to explain and reason about (if
cumbersome to use).

If \left and \right were automatic, then whenever you needed something less-
but-often-still common, like [0,1) open intervals, or physics <bra|ket>
notation, that would require kludges.

Whether or not it is a smart decision is a different argument.

~~~
ves
Why not make auto-sizing the default and manual size control the exceptional
case? It's already like this "in reality," I just wish the language would
follow that.

I use templates so my editor shims in the above anyway, at the cost of lots of
noise.

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yorwba
This looks really good, but you might want to hire a copy-editor in the
future:

Most ~~of~~ symbols are the same in \inline-math and \math-container, but
there are ~~one~difference~~ _some differences_ , these symbols below will be
display _ed_ in smaller fonts

Additionally, when I copy-pasted this here from your document, it included a
bunch of metadata you probably don't want to expose to users. I think there is
a way to set different clipboard contents for different MIME types, maybe look
into that.

~~~
buiducnha
With Inline Math (\inline-math), there are some symbols will be displayed
smaller (by default) than Display Mode (math-container). This is because I
implement it to be the same with LATEX style, maybe most of people dont want
that behavior, so may possibly change in future.

Good advice on MIME types, thanks.

~~~
andrewjw
The comment above with ~~~ was trying to give you grammar help, not content
help.

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edanm
This is really awesome, I'm going to be trying it out over the next few days.
I'm by no means a Latex expert, but it seems like it could make writing Latex
a bit faster and more wysiwyig-ish.

One question - if I want to write a^(b+c), I'll normally write in latex:
a^{b+c} to group the b+c as part of the power. I can't figure out how to do
the same in the editor - if I write in a^b+c, anything after the "b" will go
back down and will no longer be superscripted.

~~~
buiducnha
Hi, that's intentional, because we see that most of the time superscript input
is only one character, you can press arrow left to go back and input more
characters.

Maybe in future I should have a setting to turn off that feature/behavior.

Thanks.

~~~
edanm
OK I feel a bit silly because I didn't realize you could just press left and
go back to editing it. It's not even unintuitive, this is exactly the behavior
of e.g. grapher, which I use all the time, I really have no excuse.

------
Kagerjay
That was one seriously impressive 3 min video. Explained everything you wanted
to know about the platform without any audio needed either

Im going to definitely try this out later

------
johndough
This seems to be broken for keyboards without QWERTY layout (about half of
Europe) because math mode can not be entered with the '\'-key.

~~~
buiducnha
Thanks for feedback, did not aware of different type of keyboard layouts!

~~~
sharigram
I'm using international QWERTY and can't use it either.

------
dbranes
The diagramming tools look promising, great work!

I never felt like I needed a WYSIWYG for Latex. But I deifnitely need a
WYSIWYG for tikz[0]. For example, the tikz code for a simple diagram [1] is
essentially incomprehensible. So in light of this:

1\. I'm having trouble finding an image (especially vector format) export
feature, do you have it?

2\. Feature request: export diagrams to tikz code.

[0]
[https://en.wikipedia.org/wiki/PGF/TikZ](https://en.wikipedia.org/wiki/PGF/TikZ)

[1] [http://www.texample.net/tikz/examples/labeled-
chain/](http://www.texample.net/tikz/examples/labeled-chain/)

~~~
IshKebab
> I deifnitely need a WYSIWYG for tikz

I just use IPE. It's a nice GUI diagram editor that can save as PDF (as in,
the PDF contains the IPE data). Far better than faffing around with tikz.

[http://ipe.otfried.org/](http://ipe.otfried.org/)

------
kevinb7
Nice work. The drawing recognition feature seemed to work well. One little
thing that could be improve is enforcing a minimum font size so that deeply
nested fractions don't become unreadably small.

------
jxy
Looks nice. Would there be a native version, for which data are only stored
locally? You would certainly have some professional market with that. I would
pay for it just to replace LaTeXiT.

~~~
ttd
I recently released Vexlio ([https://vexlio.com](https://vexlio.com)), a
desktop (i.e. non-browser) diagramming application, that supports editing of
embedded LaTeX equations which you can then easily export to PDF, SVG or PNG.
Currently Windows only, but Mac is coming very soon now.

~~~
vram22
Interesting. If not confidential, what language did you use to create Vexlio?
and what library (if any) for PDF and PNG output? Asking since PDF generation
is one of my interests.

~~~
ttd
Not confidential -- Vexlio's written in C#, and uses Xamarin.Mac for the
bindings to the Mac world. PDF and PNG are both generated by the Skia library
(skia.org).

~~~
vram22
Thanks, had not heard of Skia. Will check it.

------
kerneldeveloper
There is also a tool which can convert Latex equations into images:
[http://www.sciweavers.org/free-online-latex-equation-
editor](http://www.sciweavers.org/free-online-latex-equation-editor)

------
Hengjie
You guys really need to compete against Wiris in the K12 Education space. If
you ever want to see this introduced to the US edu market, ping me a line.

~~~
posterboy
is that pronounced like virus?

~~~
Hengjie
Yes

------
rmbeard
This looks really good. The main application I would have for this is online
teaching, where previously I would have used WolframAlpha, so while this does
not have computational functionality it looks like it might be superior as a
communication tool. The one thing I would like to see is support for mobile
devices.

------
gabrielgoh
to those who are looking for a WYSIWYG editor which supports latex, try LyX.
It's good and intuitive enough that I have used it as a tool for thought, and
prefer to work straight from latex rather than a whiteboard or a paper and
pen.

~~~
jgtrosh
Haven't used it in a while, but I think this public should also take a look at
TeXmacs. I've long stopped caring about anything WYSIWYG but that software
seemed to me to strike a very well designed balance between WYSIWYG/fast-input
(though with a steeper learning curve than M$Word, but very approachable) and
showing what's under the hood.

~~~
kipari
Are you able to give a quick overview of some of the differences between
TeXmacs and LyX. As a longtime LyX user, the two applications look very much
alike.

------
ChuckMcM
It would be awesome to add this to tydig. (iPad calculation application) I
really wish I had something like my Ti92 wide body on the iPad with an editor
that was this easy to use.

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samcat116
Seems very similar to Swift Calcs -
[https://www.swiftcalcs.com/home](https://www.swiftcalcs.com/home)

------
lousken
Definitely adding this to my favourites, but I wonder if you could export
those diagrams to latex using tikz?

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michaelmior
> a fast way to write and share mathematics formula

This should probably read "share mathematical formulas"

Looks pretty cool though :)

~~~
buiducnha
Thanks, sorry for that bad English :)

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be5invis
I guess you (or your company) does not have any Windows PC.

~~~
thamtudethuong
Yes, what is the problems with Windows PC?

~~~
be5invis
The website works well in Edge but you claimed that it does not support that.
I have to override the user agent in order to access your editor.

~~~
buiducnha
The reason is we did not test carefully on Edge, may have some problems we
don't know!

------
lauretas
License?

~~~
buiducnha
It's free to use, currently there is a limit of 50 documents (to avoid people
create unlimited documents), will increase that limit.

~~~
bryanph_
Have you considered open sourcing and selling commercial licenses for
integration? I think this is a product that many corporations would love to
integrate with. However, as an alone standing product I don't think it adds a
lot of value. Something like the business model of draw.io

~~~
buiducnha
Very good point, did think about that, but until now still not very sure about
business model. At the beginning, when we build it, we want to have a editor
for people to easily type and share their Math (even without knowing LATEX).
Will definitely consider/think about Integration, or somethings else ...

Thanks.

------
kensai
Sometimes the HN algorithm baffles me. This article has already be submitted
by the same person, a couple of days ago. I even asked a question there.

How is it that the comments there are not included here, given the same link?
Or is it not the same link?!

[https://news.ycombinator.com/item?id=14968483](https://news.ycombinator.com/item?id=14968483)

~~~
buiducnha
Hi, I submitted again because at that time I did not know and did not post
with Prefix "Show HN:". Maybe that's reason?

~~~
kensai
If the link was the same, shouldn't you get a warning that this was already
submitted? If I submit something that has already been submitted, HN
automatically give a point to the previous submission.

Which is the way I expect it to work to avoid double submission and parallel
discussions. The thing is: I have not quite understood why sometimes it works
and others not.

~~~
scribu
Submitting an identical link starts working after a few days since the
previous submission.

~~~
kensai
Is there a technical reason for this?

