vector parsing problem, matrix support about mathquill HOT 13 CLOSED

1. yep, same went for \sqrt[n]{} and still goes for whitespace (\,,
   \:, \;, \!)
2. yeah, \vector is meant for column vectors:
   http://en.wikipedia.org/wiki/Column_vector
   matrices are basically not supported at all. If you like, you could try
   implementing a \matrix command that's similar to \vector but uses
   <table><tr><td></table> as it's html_template. You may have to override
   MathCommand::initBlocks.

Han

On Fri, Apr 22, 2011 at 12:37 PM, jenseng <
[email protected]>wrote:

it looks like there are a couple problems around matrices:

1. when you create a matrix in mathquill, the generated latex cannot
   actually be parsed by mathquill. e.g. typing \vectorab
   gives you the latex \begin{matrix}a\b\end{matrix}. when you try to
   write that to mathquill, the rendered latex in mathquill just looks like
   begin{matrix.
2. mathquill matrices don't really support columns. you can separate
   elements in a row with spaces, but you can't actually make true columns
   (separated by &) in latex. the effect is that it's difficult/impossible to
   get your columns lined up when cells are different sizes. e.g. we should be
   able to do stuff like this: http://latex.codecogs.com/gif.latex
   ?\begin{matrix}a+1&b\c&d\end{matrix}

Reply to this email directly or view it on GitHub:
https://github.com/laughinghan/mathquill/issues/31

from mathquill.

k that makes sense, i'll take a stab at it ... i guess the only real issue with vectors is that mathquill doesn't parse the generated latex. that might be a little tricky to fix short of implementing matrices

from mathquill.

from mathquill.

what, two weeks of working with LaTeX doesn't make me an expert? :P

if i do anything around this, it'll be in its own experimental branch

from mathquill.

just intresting how current selection will work with table

<table>
<tr>
<span class="selection">
<td>1<td><td>2
</span>
<tr><td>3<td><td>4<td></tr>
</table>

from mathquill.

uh, does it? It would depend a lot on how the table is represented in the Math DOM

from mathquill.

Does it means that I can not to select a row? just td or table

from mathquill.

Matrix draft version

.mathquill-rendered-math .mtable {
  text-align: center;
  display: inline-table;
}

.mathquill-rendered-math .mtr {
  margin: .2em 0;
  display: table-row !important;
  display: block;
}

.mathquill-rendered-math .mtd {
  white-space: nowrap;
  padding: 0 .1em;
  display:table-cell !important;
  display:inline-block;
}


function Matrix(replacedFragment) {
  MathCommand.call(this, '\\matrix', undefined, undefined, replacedFragment);
}
_ = Matrix.prototype = new MathCommand;
_.html_template = ['<table class="mtable"><tr class="mtr"><td class="mtd"></td></tr></table>'];

_.initBlocks = function(replacedFragment) {
  var self = this;

  var newBlock, prev;
  this.firstChild = newBlock = prev =
    (replacedFragment && replacedFragment.blockify()) || new MathBlock;

  newBlock.jQ = $("<span></span>")
    .data(jQueryDataKey, {block: newBlock})
    .append(newBlock.jQ)
    .appendTo(self.jQ.find("td"));

  newBlock.blur();
  self.lastChild = newBlock;
  newBlock.parent = self;
};

_.placeCursor = function(cursor) {
  this.cursor = cursor.appendTo(this.firstChild);
};

_.latex = function() {
  return '\\begin{matrix}' + this.foldChildren([], function(latex, child) {
    latex.push(child.latex());
    return latex;
  }).join('\\\\') + '\\end{matrix}';
};
_.text = function() {
  return '[' + this.foldChildren([], function(text, child) {
    text.push(child.text());
    return text;
  }).join() + ']';
}     

_.keydown = function(e) {
  var currentBlock = this.cursor.parent;
  var self = this;
  if (currentBlock.parent === this) {
    if (e.which === 13) { //enter
      var tr = $('tr:last', this.jQ).clone(true);
      var cb;
      tr.find("td").html('').each(function(){
        $(this).addClass("mtd");  
        var newBlock = new MathBlock;
        cb = cb || newBlock;
        newBlock.parent = self;
        newBlock.jQ = $('<span></span>').data(jQueryDataKey, {block: newBlock}).appendTo(this);
        newBlock.prev = self.lastChild;
        self.lastChild.next = newBlock; 
        self.lastChild = newBlock;
        self.cursor.appendTo(newBlock);
      });
      self.cursor.appendTo(cb).redraw();
      tr.appendTo(this.jQ);
      return false;
    }
    else if (e.which === 9 && !e.shiftKey && !currentBlock.next && self.jQ.find("tr").length == 1) { //tab
        var newBlock = new MathBlock;
        newBlock.parent = this;
        var td =  $('<td class="mtd"></td>').appendTo(currentBlock.jQ.parent().parent());
        newBlock.jQ = $('<span></span>').data(jQueryDataKey, {block: newBlock}).appendTo(td);
        this.lastChild = newBlock;
        currentBlock.next = newBlock;
        newBlock.prev = currentBlock;
        this.cursor.appendTo(newBlock).redraw();
      return false;
    } else if (e.which === 8) { //backspace
      if (currentBlock.isEmpty()) {
        if (currentBlock.prev) {
          this.cursor.appendTo(currentBlock.prev);

        } else {
          this.cursor.insertBefore(this);
        }
        return false;
      }
      else if (!this.cursor.prev)
        return false;
    }
  }
  return this.parent.keydown(e);
};

from mathquill.

damn it you're right, you can't select tds or trs if Selection has to be a span. That's why array is currently implemented by having the children be display:block, which won't work well for more than one column, unless we hack it to set the width on redraw or something. An inline table clearly makes the most sense for matrices, it seems like what we should do is addClass('selection') to the trs.

I'm not sure how best to change the architecture to support that, perhaps some way of moving the selection methods Cursor::selectLeft, selectRight, selectFrom and Selection::levelUp to MathElement or something so they can be overridden.

from mathquill.

is it possible to type squareroot as sqrt as it is in desmos calculator and not as "\sqrt" ?

from mathquill.

I experienced this issue today ("begin{matrix") and wonder after 2 years if any update or fix is available somehow?

from mathquill.

The current plan is to simply remove the current implementation of \vector, which was never very well thought-through. We do have some ideas for making a table-based vector or matrix environment, but they'll need to be much more deeply integrated than that was, to avoid problems like this.

from mathquill.

See #187.

from mathquill.