Convert an Equation Editor Object back to plain text

[Muskyboi]

Is there a tool that can convert something like this:

which when copied as plain text looks like this: \frac{4}{\pi}\sin\left(x\right)+\frac{4}{3\pi}\sin\left(3x\right)+\frac{4}{5\pi}\sin\left(5x\right)+\frac{4}{7\pi}\sin\left(7x\right)+\frac{4}{9\pi}\sin\left(9x\right)

To this: 4/pi*sin(x)+4/(3pi)*sin(3x)+4/(5pi)*sin(5x)+4/(7pi)*sin(7x)+4/(9pi)*sin(9x)

 

[jedishrfu]

I’ve not heard of such a tool. However, pandoc can do a variety of conversions to and from latex.

https://tex.stackexchange.com/questions/252203/tex-to-plain-text-or-doc

and here’s a list of other possible tools and plugins that do conversions

https://www.tug.org/utilities/texconv/textopc.html

it would be an interesting parsing project in a Comp Sci course on Compilers.

 

[berkeman]

Is there a tool that can convert something like this:
View attachment 266516

which when copied as plain text looks like this: \frac{4}{\pi}\sin\left(x\right)+\frac{4}{3\pi}\sin\left(3x\right)+\frac{4}{5\pi}\sin\left(5x\right)+\frac{4}{7\pi}\sin\left(7x\right)+\frac{4}{9\pi}\sin\left(9x\right)

To this: 4/pi*sin(x)+4/(3pi)*sin(3x)+4/(5pi)*sin(5x)+4/(7pi)*sin(7x)+4/(9pi)*sin(9x)

What format is the source? Is it just a JPEG or BMP picture, or a PDF snapshot? Or something copy/pasted from MSWord? The source format will make a big difference in how difficult the conversion will be, IMO.

it would be an interesting parsing project in a Comp Sci course on Compilers.

Absolutely. It would be a fun project, if the input format was something reasonable (instead of having to do full character recognition from a BMP file as a first step).

 

[jedishrfu]

I thought the source was just the latex string to convert to a plain text target

A related fun project would be conversion to character graphics:

              //\\ pi/2
            //
           // sin(x) dx
          //
       \\// 0

come in useful source code

This would come in useful in source code comments or markdown where the viewer uses character graphics.

 

[berkeman]

Oh, oops, I think you're right. I misread the OP to be "convert from this math equation to LaTeX". Sorry, nothing to see here, everybody move along...

 

[berkeman]

I thought the source was just the latex string to convert to plain text

And yeah, that's a MUCH easier problem to assign in a compiler class.

 

[FactChecker]

What about exporting it as a PDF or PNG file and using OCR software? I tried with FreeOCR on the PNG in the OP, but it did not do very well. Maybe better OCR software would do a better job.

FreeOCR converted it to
%si.1.1[x)+% sin(3x)+% sin(5x)+% sin(Tx) + sin[9.\'

Not a good result. But I have seen OCR software do some impressive things.
PS. I just tried a couple of online TEX to TXT converters and they did not work well.

 

[robphy]

Input: \frac{4}{\pi}\sin\left(x\right)+\frac{4}{3\pi}\sin\left(3x\right)+\frac{4}{5\pi}\sin\left(5x\right)+\frac{4}{7\pi}\sin\left(7x\right)+\frac{4}{9\pi}\sin\left(9x\right)https://www.wolframalpha.com/input/?i=+\frac{4}{\pi}\sin\left(x\right)+\frac{4}{3\pi}\sin\left(3x\right)+\frac{4}{5\pi}\sin\left(5x\right)+\frac{4}{7\pi}\sin\left(7x\right)+\frac{4}{9\pi}\sin\left(9x\right)

produces

4/π sin(x) + 4/(3 π) sin(3 x) + 4/(5 π) sin(5 x) + 4/(7 π) sin(7 x) + 4/(9 π) sin(9 x)
also interesting:

https://mathpix.com/
http://www.i2ocr.com/free-online-math-equation-ocr
http://www.inftyproject.org/en/index.html

 

[Muskyboi]

Input: \frac{4}{\pi}\sin\left(x\right)+\frac{4}{3\pi}\sin\left(3x\right)+\frac{4}{5\pi}\sin\left(5x\right)+\frac{4}{7\pi}\sin\left(7x\right)+\frac{4}{9\pi}\sin\left(9x\right)https://www.wolframalpha.com/input/?i=+\frac{4}{\pi}\sin\left(x\right)+\frac{4}{3\pi}\sin\left(3x\right)+\frac{4}{5\pi}\sin\left(5x\right)+\frac{4}{7\pi}\sin\left(7x\right)+\frac{4}{9\pi}\sin\left(9x\right)

View attachment 266604
produces

4/π sin(x) + 4/(3 π) sin(3 x) + 4/(5 π) sin(5 x) + 4/(7 π) sin(7 x) + 4/(9 π) sin(9 x)
also interesting:

https://mathpix.com/
http://www.i2ocr.com/free-online-math-equation-ocr
http://www.inftyproject.org/en/index.html

This is exactly what I was looking for. Thank you.

 

[BvU]

produces

4/π sin(x) + 4/(3 π) sin(3 x) + 4/(5 π) sin(5 x) + 4/(7 π) sin(7 x) + 4/(9 π) sin(9 x)

For the record: When you hover the mouse over the picture of the equation, extra buttons appear and the one on the right brings up the plain text

 

[FactChecker]

The only potential problem with Wolfram's plain text is that it uses the extended character set, so $\pi$ instead of Pi. That is acceptable in many places that you might paste it, but not everywhere.

 

[BvU]

Turns out Excel () accepts $\pi$ as a name, but of course it wants all the asterisks

π 3.141592654 (formulas|create from selection)

=4/π* sin(x) + 4/(3 *π) *sin(3* x) + 4/(5 *π) *sin(5* x)+ 4/(7 *π)* sin(7 *x) + 4/(9* π) *sin(9* x)

does the work an comes up with a value

 

[robphy]

Possibly useful (I haven't tried them):

https://github.com/mtarek/compitex "Convert LaTeX equations to equivalent C-Code."
https://www.codeproject.com/Articles/30615/Converting-math-equations-to-C " A magical tool to convert Word equations to C# - instantly! " (uses MathML)