       few things would be nice to have in next version of Mathematica

• To: mathgroup at smc.vnet.net
• Subject: [mg114619] few things would be nice to have in next version of Mathematica
• From: "Nasser M. Abbasi" <nma at 12000.org>
• Date: Fri, 10 Dec 2010 02:31:35 -0500 (EST)

```I thought I take a minute to write down few things before I
forget them, that I think would be nice to have in Mathematica

1) Need an Incomplete Cholesky decomposition function. Could
add an option to current Cholesky decomposition function to
allow one to supply a drop tolerance value. Mathematica only
has Cholesky decomposition

2) Function for Matrix condition number for dense matrices, and
Matrix condition number estimator for sparse matrices. Both are
missing now.

3) On the documentation center, if someone makes a typo, it would
be nice if the system asked one "did you mean that?" and gave
some options. (as Google does when one makes a typo in search)

For example, typing ref/SHow gives an error because one did not
type ref/show.

4) It would be nice to combine plots using Show[] and have an
option for automatic styling so that the plots all come out
with different colors.

Doing

p1=Plot[Sin[x],{x,-Pi,Pi}];
p2=Plot[Cos[2 x],{x,-Pi,Pi}];
Show[p1,p2]

shows all plots with same color. One will have to give
a PlotStyle to each separate plot before and have to
think of different color to use which is not used by
other plots.

For convenience, it will be nice to have the system automatically
pick different colors, and also have the legend be such that
it matches the order the plots are put together. Similar to
what one does with PlotLegend:

Needs["PlotLegends`"]
Plot[{Sin[x],Cos[x]},{x,-Pi,Pi},PlotLegend->{"sine","cosine"}]

But have the above work with Show as well, as in:

Show[p1,p2,ShowLegend->{"sine","cosine"}]
and have each plot p_i (or graphic object p_i in general) be
colored differently automatically and have this reflected in
the legend generated (as what happens in PlotLegend).

Speaking of PlotLegend, it would be nice to be able to adjust
the location of it on the plot by using the mouse once the plot
is rendered and be able to move it to different location by the
mouse and adjust its size. I tried using V 8 with the new
nice and improved drawing tools, but did not know how to do
that yet. May be there is a way.

I have few more, but need to work on that little more, may later