How to configure MathJax (AsciiMath) to permit thousands separators - mathjax

Question

MathJax with AsciiMath renders the expression 1,000/5 as 1, 000/5, where the numerator of the fraction just shows as 000 instead of 1,000.
JSFiddle: https://jsfiddle.net/kai100/wLhbqkru/
The MathJax documentation is silent about thousands separators.
The Stack Overflow answer below answers this question for TeX input, but I need it for input in AsciiMath format, and have not been able to make it work by changing "Tex" to "AsciiMath" in the config file:
mathjax commas in digits
Any help would be much appreciated. Thank you.

Answer 1

Setting
decimal: ','
tells AsciiMath to use the European number format, which uses a comma as the decimal place separator rather than a period. That is why you are not longer seeing "0.12" treated as a number. AsciiMath does not have a mechanism of parsing commas every three digits.
The best I can suggest is use a AsciiMath pre-filter to pre-process the AsciiMath to remove the commas before AsciiMath parses the expression. Adding something like
<script type="text/x-mathjax-config">
MathJax.Hub.Register.StartupHook("AsciiMath Jax Ready", function () {
function removeCommas(n) {return n.replace(/,/g,'')}
MathJax.InputJax.AsciiMath.prefilterHooks.Add(function (data) {
data.math = data.math.replace(/\d{1,3}(?:\,\d\d\d)+/g,removeCommas);
});
});
</script>
to the page just before the script that loads MathJax.js should do the trick. Note that this will mean the commas don't appear in the output, either; there is no natural way to do that, unless you wanted to add commas to ALL numbers that have 4 or more digits (even if they didn't have commas to start with). That would require a post-filter to go back over the MathML that is produced and convert the numbers to having the commas. Something like:
MathJax.Hub.Register.StartupHook("AsciiMath Jax Ready", function () {
function removeCommas(n) {
return n.replace(/,/g,'');
}
function addCommas(n){
return n.replace(/\B(?=(\d{3})+(?!\d))/g, ",");
}
function recursiveAddCommas(node) {
if (node.isToken) {
if (node.type === 'mn') {
node.data[0].data[0] = addCommas(node.data[0].data[0]);
}
} else {
for (var i = 0, m = node.data.length; i < m; i++) {
recursiveAddCommas(node.data[i]);
}
}
}
MathJax.InputJax.AsciiMath.prefilterHooks.Add(function (data) {
data.math = data.math.replace(/\d{1,3}(?:\,\d{3})+/g, removeCommas);
});
MathJax.InputJax.AsciiMath.postfilterHooks.Add(function (data) {
recursiveAddCommas(data.math.root);
});
});
should work.

Answer 2

The AsciiMath configuration options are unfortunately not properly documented.
You can specify this via
//...
AsciiMath: {
decimal: ","
},
//...
in your MathJax configuration block.
Note that this causes various parsing complications for (e.g., (1,2) ).
For completion, the documentation is at http://docs.mathjax.org/en/latest/options/input-processors/AsciiMath.html