Dotless i and j

cepheid

I'm wondering how to get dotless i and j in LaTeX on the forums. For some reason, \i and \j don't work for this. I can use \imath and \jmath, and I can even get carets on them to represent unit vectors:

[tex] \hat{\imath}, \hat{\jmath} [/tex]

The only remaining problem is that I can't get them to be typeset in boldface and upright as vectors traditionally are. If I do this hack:

[tex] \hat{\textbf{$\imath$}}, \hat{\textbf{$\jmath$}} [/tex]

then I can get them boldface, but still not upright. I think that the glyphs for \imath and \jmath are inherently italicized and there is no way to change this. Any suggestions for the OCD among us?

robphy

From
http://groups.google.com/group/mathj...%2F2010-11%3F&
MathJax can use unicode...

[tex]\mbox{abcdefgh}\ \unicode{x0131}\unicode{x0237}\ \mbox{klmnopqrstuvwyz}[/tex]

You could define a macro for \i and \j
[itex]\def\i{\unicode{x0131}} \i [/itex] [itex]\def\j{\unicode{x0237}} \j [/itex] (right-click show source)

then use it later
[tex]\i i\mbox{i}[/tex] [tex]\j j\mbox{j}[/tex]

cepheid

So, definitions that people make using \def are universal and permanent (or at least persist until some user gives the same macro a different definition)???

In any case, it still doesn't work:

[tex]\def\i{\unicode{x0131}} \hat{\mathbf{\i}} [/tex]

robphy

How's this?

[itex]\def\ihat{\hat{\unicode{x0131}\!\!\unicode{x0131}}} \ihat [/itex] [itex]\def\jhat{\hat{\unicode{x0237}\!\!\!\unicode{x0237}}} \jhat [/itex]

[tex] 8\ihat + 6\jhat[/tex]

I suspect your \defs are local to your post.

cepheid

That's very interesting! I just read that \! inserts a small negative space. So you have two unicode dotless i's slightly overlapping each other to produce a thicker one. It's very clever. Why the extra space for the j? Why not:


[itex]\def\jhat{\hat{\unicode{x0237}\!\!\unicode{x0237}}} \jhat [/itex]


Ah. That's why. A line thickness problem.