Dear developers,

first of all let me congratulate you and thank you
for the wonderful environment that you have provided
with LyX. I have now completely switched to LyX in all
my publications and am currently using it for writing
a book.

Let me also mention, that for me the point to switch
to LyX came with the availability of "instant preview"
in combination with the "xypic"-package of Kris Rose.
I have provided a manual for using LyX with xypic, which
is available at
http://www.mathematik.uni-marburg.de/~gumm/LyX/xypic.pdf

I am currently using
  - LyX 1.3.7pre6 (installed with Uwe Stöhr's installer)
  - MikTeX,
  - Windows XP

Now here are three problems with LyX's math editor.
All three assume that in your preamble you have loaded

  \usepackage[all]{xy}

The folling code will (correctly) produce a vertical
arrow from A to B labeled with f :

  \xymatrix{A\ar[d]^f \\ B}

 ( Select the text and press Ctrl-M to make the finished
  diagram visible in LyX )

Problem #1:
-----------
  In LaTeX/xypic I can shift the label f from the middle
  of the arrow towards its tip or towards its tail by
  prefixing it with a ratio. For instance,

    \xymatrix{A\ar[d]^(0.2)f \\ B}

  will place the label 1/5 of the way between start and
  end of the arrow. This is an important feature for my
  purposes, but it does not work in LyX.
  LyX will incorrectly interpret the opening parenthesis
  "(" as label.

Problem #2:
-----------
  I have found a strange way to "solve" the problem. That
  is, I can manage to place the label correctly inside
  the math editor. Instant preview works and the dvi
  produced is correct, too.
  However, leaving LyX and reloading the file messes up
  the diagram. Thus the editor's state is not correctly
  reloaded.

  Here are the keystrokes so you can recreate the bug:

  - Create the basic diagram by typing
     \xymatrix{A\ar[d] \\ B}
  - Select the text and enter Ctrl-M
  - Place the cursor inside the editing area just behind
    the closing square bracket, and enter
        ^\{f
    *** No space key after pressing ^ ***
    ( It will show in the editor as ^{f} )
    Place the cursor between  ^ and { and enter
         (0.2)

  Leave the editing area to see that the arrow is correctly labeled.
  But:
    Save your file, exit LyX, load it again and you will see that
    the diagram is messed up.

Problem #3:
----------
  xypic allows me to stretch diagrams by specifying row
  or column sizes.  For instance, to stretch it vertically,
  I would enter:

    [EMAIL PROTECTED] \\ B}

  Unfortunately, LyX takes the @-character literally and
  does not produce the correct diagram.


Do you have any solutions to this ? At this stage, a
workaround would also be very welcome to me.

Best regards,

H.Peter Gumm


+---------------------------------------+
| Prof. Dr. H. Peter Gumm               |
| FB Mathematik und Informatik          |
| Philipps-Universität Marburg          |
| Tel: (+49)-(0)6421-2821516 (office)   |
|      (+49)-(0)6425-6334    (home)     |
+---------------------------------------+

Reply via email to