math2svg.lua filter

math2svg/.gitignore

@@ -0,0 +1 @@
+*.swp

math2svg/Makefile

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+DIFF ?= diff --strip-trailing-cr -u
+
+test: sample.md math2svg.lua
+	@pandoc --mathml --lua-filter=math2svg.lua --to=html $< \
+	    | $(DIFF) expected.html -
+
+expected: sample.md math2svg.lua
+	pandoc --mathml --lua-filter=math2svg.lua --output=expected.html $<
+
+.PHONY: test

math2svg/README.md

@@ -0,0 +1,77 @@
+# Description
+
+This [Lua filter](https://pandoc.org/lua-filters.html)
+for [Pandoc](https://pandoc.org/)
+converts [LaTeX math](https://en.wikibooks.org/wiki/LaTeX/Mathematics)
+to [MathJax](https://www.mathjax.org/) generated
+[scalable vector graphics (SVG)](https://en.wikipedia.org/wiki/Scalable_Vector_Graphics)
+in any of the [available MathJax fonts](https://docs.mathjax.org/en/latest/output/fonts.html).
+
+This is useful when a CSS paged media engine cannot process complex JavaScript
+as required by MathJax.
+See: <https://www.print-css.rocks> for information about CSS paged media,
+a [W3C standard](https://www.w3.org/TR/css-page-3/).
+
+The filter also allows to define additional LaTeX commands.
+
+
+# Requires
+
+```bash
+$ sudo apt install pandoc nodejs npm
+$ sudo npm install --global mathjax-node-cli
+```
+
+
+# Usage
+
+To be used as a [Pandoc Lua filter](https://pandoc.org/lua-filters.html).
+[MathML](https://en.wikipedia.org/wiki/MathML) should be set as a fallback.
+
+```bash
+pandoc --mathml --filter='math2svg.lua'
+```
+
+
+# Privacy
+
+No Internet connection is established when creating MathJax SVG code using
+the `tex2svg` command of [`mathjax-node-cli`](https://github.com/mathjax/mathjax-node-cli).
+Hence, formulas in SVG can be created offline and will remain private.
+For code auditing, see also:
+
+- <https://github.com/mathjax/MathJax-node>
+- <https://github.com/pkra/mathjax-node-sre>
+
+
+# Copyright
+
+Copyright (c) 2020 Serge Y. Stroobandt
+
+
+## MIT License
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+
+# Contact
+
+```bash
+$ echo c2VyZ2VAc3Ryb29iYW5kdC5jb20K |base64 -d
+```

math2svg/expected.html

@@ -0,0 +1,94 @@
+<p>Only <strong>plane waves in the far field</strong> exhibit the <a href="https://en.wikipedia.org/wiki/Impedance_of_free_space">characteristic impedance of free space</a>, which is exactly:</p>
+<p><div class="math display"><svg xmlns:xlink="http://www.w3.org/1999/xlink" width="38.427ex" height="9.509ex" style="vertical-align: -4.171ex;" viewBox="0 -2298.3 16545 4094.3" role="img" focusable="false" xmlns="http://www.w3.org/2000/svg">
+<defs>
+<path stroke-width="1" id="E1-GYREPAGELLANORMAL-1D44D" d="M637 672l-504 -633h281c44 0 82 4 127 13c10 26 6 8 32 90l7 22h26c-13 -69 -21 -126 -23 -167l-322 3l-241 -3v22l502 633h-180c-86 0 -124 -3 -180 -13l-6 -20c-12 -39 -18 -64 -21 -86h-26c8 73 11 112 11 158l118 1l237 -3l162 3v-20Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLAMAIN-30" d="M465 366c0 -256 -76 -386 -227 -386c-62 0 -118 28 -153 77s-56 150 -56 267c0 242 79 365 234 365c137 0 202 -104 202 -323zM381 316c0 240 -39 338 -136 338c-95 0 -132 -83 -132 -294c0 -244 41 -345 138 -345c92 0 130 88 130 301Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLAMAIN-3D" d="M680 330h-600c2 10 3 20 3 30s-1 20 -3 30h600c-2 -10 -3 -20 -3 -30s1 -20 3 -30zM680 110h-600c2 10 3 20 3 30s-1 20 -3 30h600c-2 -10 -3 -20 -3 -30s1 -20 3 -30Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLAMAIN-7C" d="M128 -150c-8 2 -16 3 -24 3s-16 -1 -24 -3v800c8 -2 16 -3 24 -3s16 1 24 3v-800Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLANORMAL-1D438" d="M570 689c-11 -38 -18 -88 -21 -152h-24l-8 89c-1 15 -42 24 -107 24c-99 -2 -74 -2 -130 -4c-4 -8 -6 -16 -9 -32l-42 -238h37l219 6l4 -7l-19 -45c-31 1 -6 4 -132 4h-117l-43 -253c-2 -12 -2 -23 -2 -35c63 -6 90 -7 131 -7c60 0 131 5 150 10c21 5 30 17 39 52l16 60 h27c-8 -41 -16 -83 -21 -125l-4 -36c-39 -1 -19 -3 -105 -3l-225 3l-154 -3l5 26c44 7 57 14 60 32l87 504c6 32 9 62 9 77c0 17 -11 25 -35 26l-54 2l3 28l160 -3l236 3c23 0 47 -1 69 -3Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLAMAIN-20D7" d="M-57 664c-45 -36 -85 -76 -120 -120c-12 2 -23 3 -34 3c-12 0 -23 -1 -34 -3c28 34 58 67 91 96h-289c2 8 3 16 3 24s-1 16 -3 24h289c-33 29 -63 62 -91 96c11 -2 22 -3 34 -3c11 0 22 1 34 3c35 -44 75 -84 120 -120Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLASIZE4-7C" d="M138 -579c-10 2 -19 3 -29 3s-19 -1 -29 -3v1658c10 -2 19 -3 29 -3s19 1 29 3v-1658Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLANORMAL-1D43B" d="M800 692l-3 -28l-36 -3c-38 -3 -44 -9 -51 -48l-92 -520c-3 -17 -4 -26 -4 -35c0 -21 10 -29 36 -30l58 -3l-3 -28l-132 3l-141 -3l4 28l50 3c22 1 33 6 37 14c5 6 12 34 21 83l40 215l-184 3l-184 -3l-42 -247c-3 -19 -4 -26 -4 -35c0 -21 9 -28 36 -30l49 -3l-3 -28 l-123 3l-132 -3l4 28l41 3c40 3 42 5 58 97l74 434c5 31 9 62 9 76c0 18 -11 26 -35 27l-47 2l3 28l141 -3l114 3l-3 -28l-42 -3c-37 -3 -44 -9 -51 -48l-42 -228h370l30 174c5 30 9 62 9 76c0 18 -11 26 -35 27l-48 2l3 28l143 -3c36 0 71 1 107 3Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLANORMAL-1D707" d="M549 85c-99 -72 -137 -94 -163 -94c-19 0 -30 15 -28 40c-1 16 3 38 14 76l39 132c-32 -51 -55 -79 -97 -125c-68 -74 -134 -125 -164 -125c-3 0 -10 1 -22 4l-18 -225c-2 -13 -10 -23 -34 -32l-31 -12l-13 8l148 660c2 11 -5 20 -15 20c-9 0 -19 -5 -49 -23l-33 -21 l-7 20l30 20c76 54 113 74 134 74c14 0 22 -11 22 -32c-1 -12 -3 -26 -6 -42l-65 -271c-7 -26 -9 -37 -8 -52c-1 -17 3 -26 12 -26c41 0 123 74 184 166c31 46 56 113 74 189l11 51l68 17l8 -9l-94 -357c-6 -16 -7 -32 -8 -40c0 -10 5 -17 13 -17c12 0 36 11 62 27l26 17Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLANORMAL-1D716" d="M491 422l-41 -52l-20 -2c-7 15 -18 32 -25 39c-20 24 -53 31 -86 31c-35 0 -71 -13 -98 -37c-43 -37 -62 -90 -70 -139l108 -1l125 2l-14 -35l-6 -6l-140 1c-7 0 -55 0 -80 -3c-2 -12 -4 -25 -3 -37c1 -11 0 -22 3 -32c13 -64 77 -112 122 -112c36 0 85 17 137 55l24 17 l9 -19c-94 -74 -146 -103 -205 -103c-53 0 -107 12 -139 50c-26 32 -38 73 -38 116c0 17 0 35 4 53c18 86 54 150 117 203c55 46 118 71 183 71c53 0 102 -23 133 -60Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLASIZE5-221A" d="M787 1500h-164l-90 -2530c-14 2 -27 3 -40 3c-14 0 -27 -1 -41 -3l-266 1218h-66v60h154l210 -961l81 2273h222v-60Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLAMAIN-22C5" d="M200 250c0 -36 -24 -60 -60 -60s-60 24 -60 60s24 60 60 60s60 -24 60 -60Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLANORMAL-1D450" d="M389 458c-9 -26 -16 -63 -24 -128h-23v60c0 24 -36 43 -81 43c-32 0 -57 -8 -78 -26c-48 -39 -82 -142 -82 -248c0 -79 29 -119 85 -119c35 0 73 17 145 65l15 10l8 -20l-50 -41c-55 -45 -103 -65 -157 -65c-80 0 -122 51 -122 147c0 107 38 211 95 261s128 85 173 85 c38 0 71 -8 96 -24Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLAMAIN-2248" d="M678 434c-29 -89 -62 -139 -124 -156c-13 -4 -26 -5 -38 -5c-54 0 -107 30 -154 62c-36 25 -75 53 -117 53c-8 0 -16 -1 -24 -4c-47 -13 -81 -43 -103 -110c-5 4 -12 7 -18 9s-13 3 -20 3c29 89 62 139 124 156c13 4 26 5 38 5c54 0 107 -30 154 -62 c36 -25 75 -53 117 -53c8 0 16 1 24 4c47 13 81 43 103 110c6 -4 12 -7 18 -9c7 -2 13 -3 20 -3zM678 214c-29 -89 -62 -139 -124 -156c-13 -4 -26 -5 -38 -5c-54 0 -107 30 -154 62c-36 25 -75 53 -117 53c-8 0 -16 -1 -24 -4c-47 -13 -81 -43 -103 -110c-5 4 -12 7 -18 9 s-13 3 -20 3c29 89 62 139 124 156c13 4 26 5 38 5c54 0 107 -30 154 -62c36 -25 75 -53 117 -53c8 0 16 1 24 4c47 13 81 43 103 110c6 -4 12 -7 18 -9c7 -2 13 -3 20 -3Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLAMAIN-33" d="M462 224c0 -47 -17 -91 -51 -132c-55 -67 -147 -112 -227 -112c-37 0 -81 8 -134 26c-6 50 -14 86 -35 147l27 10c19 -54 32 -77 56 -99c30 -28 71 -43 117 -43c93 0 154 67 154 169c0 91 -48 144 -131 144c-27 0 -46 -5 -84 -22l-7 6l12 53s39 -3 47 -3 c71 0 130 63 130 138c0 63 -53 116 -118 116c-52 0 -115 -34 -126 -68l-18 -56h-31l29 124c48 48 93 67 161 67c111 0 185 -59 185 -148c0 -59 -30 -105 -110 -167c50 -9 73 -17 98 -35c36 -25 56 -67 56 -115Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLAMAIN-37" d="M497 659l-183 -329c-89 -159 -115 -224 -157 -333c0 0 -28 3 -46 3s-46 -3 -46 -3l-9 13l244 392c38 61 69 119 109 201h-267c-46 0 -53 -8 -61 -70l-7 -56h-30s3 62 3 102c0 41 -3 105 -3 105l10 5c97 -4 114 -5 219 -5c107 0 116 1 224 5v-30Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLAMAIN-36" d="M468 219c0 -136 -97 -239 -227 -239c-129 0 -209 102 -209 267c0 137 56 259 159 346c51 44 92 64 188 96l37 -17v-8c-180 -54 -264 -152 -285 -333c66 54 103 78 162 78c106 0 175 -75 175 -190zM382 184c0 99 -51 165 -127 165c-48 0 -95 -24 -117 -58 c-11 -17 -15 -36 -15 -71c0 -134 46 -207 131 -207c77 0 128 67 128 171Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLAMAIN-2E" d="M183 53c0 -31 -28 -58 -60 -58c-29 0 -56 28 -56 58s27 58 57 58c31 0 59 -28 59 -58Z"></path>
+<path stroke-width="1" id="E1-GYREPAGELLAMAIN-3A9" d="M801 158c-6 -43 -7 -112 -7 -161c-21 0 -81 3 -119 3c-23 0 -98 0 -119 -3h-22v39c9 9 23 13 38 23c6 4 15 14 25 29c27 40 79 155 79 247c0 212 -79 332 -256 332s-257 -119 -257 -332c0 -92 52 -207 79 -247c10 -15 19 -25 25 -29c14 -10 29 -14 38 -23v-39h-22 c-21 3 -96 3 -119 3c-38 0 -98 -3 -119 -3c0 49 -1 118 -7 161h26l7 -52c4 -29 17 -37 36 -37h115c-63 53 -166 170 -166 302c0 207 139 338 364 338s363 -132 363 -338c0 -132 -103 -249 -166 -302h115c19 0 32 8 36 37l7 52h26Z"></path>
+</defs>
+<g stroke="currentColor" fill="currentColor" stroke-width="0" transform="matrix(1 0 0 -1 0 0)">
+ <use xlink:href="#E1-GYREPAGELLANORMAL-1D44D" x="0" y="0"></use>
+ <use transform="scale(0.707)" xlink:href="#E1-GYREPAGELLAMAIN-30" x="943" y="-213"></use>
+ <use xlink:href="#E1-GYREPAGELLAMAIN-3D" x="1399" y="0"></use>
+<g transform="translate(2159,0)">
+<g transform="translate(397,0)">
+<rect stroke="none" width="1357" height="60" x="0" y="220"></rect>
+<g transform="translate(154,1099)">
+ <use xlink:href="#E1-GYREPAGELLASIZE4-7C"></use>
+<g transform="translate(218,0)">
+ <use xlink:href="#E1-GYREPAGELLANORMAL-1D438" x="0" y="0"></use>
+ <use xlink:href="#E1-GYREPAGELLAMAIN-20D7" x="526" y="257"></use>
+</g>
+ <use xlink:href="#E1-GYREPAGELLASIZE4-7C" x="830" y="0"></use>
+</g>
+<g transform="translate(60,-1100)">
+ <use xlink:href="#E1-GYREPAGELLASIZE4-7C"></use>
+<g transform="translate(218,0)">
+ <use xlink:href="#E1-GYREPAGELLANORMAL-1D43B" x="0" y="0"></use>
+ <use xlink:href="#E1-GYREPAGELLAMAIN-20D7" x="635" y="257"></use>
+</g>
+ <use xlink:href="#E1-GYREPAGELLASIZE4-7C" x="1019" y="0"></use>
+</g>
+</g>
+</g>
+ <use xlink:href="#E1-GYREPAGELLAMAIN-3D" x="4312" y="0"></use>
+<g transform="translate(5351,0)">
+ <use xlink:href="#E1-GYREPAGELLASIZE5-221A" x="0" y="-75"></use>
+<rect stroke="none" width="1410" height="60" x="757" y="1426"></rect>
+<g transform="translate(757,0)">
+<g transform="translate(120,0)">
+<rect stroke="none" width="1170" height="60" x="0" y="220"></rect>
+<g transform="translate(60,796)">
+ <use xlink:href="#E1-GYREPAGELLANORMAL-1D707" x="0" y="0"></use>
+ <use transform="scale(0.707)" xlink:href="#E1-GYREPAGELLAMAIN-30" x="843" y="-213"></use>
+</g>
+<g transform="translate(113,-686)">
+ <use xlink:href="#E1-GYREPAGELLANORMAL-1D716" x="0" y="0"></use>
+ <use transform="scale(0.707)" xlink:href="#E1-GYREPAGELLAMAIN-30" x="692" y="-213"></use>
+</g>
+</g>
+</g>
+</g>
+ <use xlink:href="#E1-GYREPAGELLAMAIN-3D" x="7796" y="0"></use>
+<g transform="translate(8834,0)">
+ <use xlink:href="#E1-GYREPAGELLANORMAL-1D707" x="0" y="0"></use>
+ <use transform="scale(0.707)" xlink:href="#E1-GYREPAGELLAMAIN-30" x="843" y="-213"></use>
+</g>
+ <use xlink:href="#E1-GYREPAGELLAMAIN-22C5" x="10107" y="0"></use>
+<g transform="translate(10610,0)">
+ <use xlink:href="#E1-GYREPAGELLANORMAL-1D450" x="0" y="0"></use>
+ <use transform="scale(0.707)" xlink:href="#E1-GYREPAGELLAMAIN-30" x="576" y="-213"></use>
+</g>
+ <use xlink:href="#E1-GYREPAGELLAMAIN-2248" x="11749" y="0"></use>
+<g transform="translate(12785,0)">
+ <use xlink:href="#E1-GYREPAGELLAMAIN-33"></use>
+ <use xlink:href="#E1-GYREPAGELLAMAIN-37" x="500" y="0"></use>
+ <use xlink:href="#E1-GYREPAGELLAMAIN-36" x="1001" y="0"></use>
+ <use xlink:href="#E1-GYREPAGELLAMAIN-2E" x="1501" y="0"></use>
+ <use xlink:href="#E1-GYREPAGELLAMAIN-37" x="1752" y="0"></use>
+ <use xlink:href="#E1-GYREPAGELLAMAIN-33" x="2252" y="0"></use>
+</g>
+ <use xlink:href="#E1-GYREPAGELLAMAIN-3A9" x="15705" y="0"></use>
+</g>
+</svg>
+</div></p>
+<div class="line-block">where:<br />
+<math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>c</mi><mn>0</mn></msub><mo>=</mo><mn>299</mn><mspace width="0.167em"></mspace><mn>792</mn><mspace width="0.167em"></mspace><mn>458</mn><mspace width="0.167em"></mspace><mfrac><mtext mathvariant="normal">m</mtext><mtext mathvariant="normal">s</mtext></mfrac></mrow><annotation encoding="application/x-tex">c_0 = 299\,792\,458\,\frac{\text{m}}{\text{s}}</annotation></semantics></math>: the speed of light in free space<br />
+<math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>μ</mi><mn>0</mn></msub><mo>=</mo><mn>4</mn><mi>π</mi><mo>⋅</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>7</mn></mrow></msup><mfrac><mtext mathvariant="normal">H</mtext><mtext mathvariant="normal">m</mtext></mfrac></mrow><annotation encoding="application/x-tex">\mu_0 = 4\pi\cdot10^{-7}\frac{\text{H}}{\text{m}}</annotation></semantics></math>: the free space permeability<br />
+<math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msub><mi>ϵ</mi><mn>0</mn></msub><mo>=</mo><mfrac><mn>1</mn><mrow><msub><mi>μ</mi><mn>0</mn></msub><msubsup><mi>c</mi><mn>0</mn><mn>2</mn></msubsup></mrow></mfrac></mrow><annotation encoding="application/x-tex">\epsilon_0 = \frac{1}{\mu_0 c_0^2}</annotation></semantics></math>: the absolute permittivity of free space<br />
+<math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><msub><mi>Z</mi><mn>0</mn></msub><annotation encoding="application/x-tex">Z_0</annotation></semantics></math>: the characteristic impedance of free space</div>

math2svg/math2svg.lua

@@ -0,0 +1,137 @@
+--  DESCRIPTION
+--
+--    This Lua filter for Pandoc converts LaTeX math to MathJax generated
+--    scalable vector graphics (SVG) in any of the available MathJax fonts.
+--
+--    This is useful when a CSS paged media engine cannot process complex JavaScript
+--    as required by MathJax.
+--
+--    See: https://www.print-css.rocks for information about CSS paged media, a W3C
+--    standard.
+--
+--    The filter also allows to define additional LaTeX commands.
+
+
+--  REQUIRES
+--
+--    $ sudo apt install pandoc nodejs npm
+--    $ sudo npm install --global mathjax-node-cli
+
+
+--  USAGE
+--
+--    To be used as a Pandoc Lua filter.
+--    MathML should be set as a fallback.
+--
+--    pandoc --mathml --filter='math2svg.lua'
+--
+--    See also: https://pandoc.org/lua-filters.html
+
+
+--  PRIVACY
+--
+--    No Internet connection is established when creating MathJax SVG code using
+--    the tex2svg command of mathjax-node-cli.
+--    Hence, formulas in SVG can be created offline and will remain private.
+--
+--    For code auditing, see also:
+--      - https://github.com/mathjax/MathJax-node
+--      - https://github.com/pkra/mathjax-node-sre
+--      - https://github.com/mathjax/mathjax-node-cli
+
+
+--  COPYRIGHT
+--
+--    Copyright (c) 2020 Serge Y. Stroobandt
+--
+--    MIT License
+--
+--    Permission is hereby granted, free of charge, to any person obtaining a copy
+--    of this software and associated documentation files (the "Software"), to deal
+--    in the Software without restriction, including without limitation the rights
+--    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+--    copies of the Software, and to permit persons to whom the Software is
+--    furnished to do so, subject to the following conditions:
+--
+--    The above copyright notice and this permission notice shall be included in all
+--    copies or substantial portions of the Software.
+--
+--    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+--    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+--    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+--    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+--    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+--    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+--    SOFTWARE.
+
+
+--  CONTACT
+--
+--    $ echo c2VyZ2VAc3Ryb29iYW5kdC5jb20K |base64 -d
+
+
+--  Enter here the full path to the tex2svg binary of mathjax-node-cli.
+--  The full path can be found with the following command:
+--    $ which tex2svg
+local tex2svg = '/usr/local/lib/node_modules/mathjax-node-cli/bin/tex2svg'
+
+
+--  Supported MathJax fonts are: https://docs.mathjax.org/en/latest/output/fonts.html
+local font = 'Gyre-Pagella'
+
+
+--  Indicate with true or false whether DisplayMath and InlineMath should be converted to SVG.
+local display2svg = true
+local inline2svg  = false
+--  The fallback is MathML if pandoc is executed with the --mathml argument.
+--  MathML output gets generated much faster than SVG output.
+--  Moreover, MathML is better suited to InlineMath as line heights are kept small.
+
+
+--  Any additional LaTeX math commands can be defined here.
+--  For example:
+--  local newcommands = '\\newcommand{\\j}{{\\text{j}}}\\newcommand{\\e}[1]{\\,{\\text{e}}^{#1}}'
+local newcommands = ''
+
+
+--  The available options for tex2svg are:
+  --help        Show help                                                   [boolean]
+  --version     Show version number                                         [boolean]
+  --inline      process as in-line TeX                                      [boolean]
+  --speech      include speech text                         [boolean] [default: true]
+  --linebreaks  perform automatic line-breaking                             [boolean]
+  --font        web font to use                                      [default: "TeX"]
+  --ex          ex-size in pixels                                        [default: 6]
+  --width       width of container in ex                               [default: 100]
+  --extensions  extra MathJax extensions e.g. 'Safe,TeX/noUndefined'    [default: ""]
+
+
+function Math(elem)
+
+  if elem.mathtype == 'DisplayMath' and display2svg then
+
+    local svg = pandoc.pipe(tex2svg, {'--speech=false', '--font', font, newcommands .. elem.text}, '')
+
+    if FORMAT:match '^html.?' then
+      svg = '<div class="math display">' .. svg .. '</div>'
+      return pandoc.RawInline(FORMAT, svg)
+    else
+      local filename = pandoc.sha1(svg) .. '.svg'
+      return pandoc.mediabag.insert(filename, 'image/svg+xml', svg)
+    end
+
+  elseif elem.mathtype == 'InlineMath' and inline2svg then
+
+    local svg = pandoc.pipe(tex2svg, {'--speech=false', '--font', font, newcommands .. elem.text}, '')
+
+    if FORMAT:match '^html.?' then
+      svg = '<span class="math inline">' .. svg .. '</span>'
+      return pandoc.RawInline(FORMAT, svg)
+    else
+      local filename = pandoc.sha1(svg) .. '.svg'
+      return pandoc.mediabag.insert(filename, 'image/svg+xml', svg)
+    end
+
+  end
+
+end