mm-859
===
Subject: Re: No output or In[n] prompt appearing
that is usual a problem of the MathLink connection to the
Mathematica kernel. But I can't say more without more information.
   Jens
> I have this weird problem. When I enter anything as simple as
 2+2
 and shift+Enter, there is no error or anything. It seems that the cell
> is evaluated, but nothing shows up, not even the In[1] prompt. I do not
> know what to check or where to look. All help is very much appreciated.


===
Subject: Re: Postscipt fonts in graphics
have you a PostScript (*.pfb) and a metric file (*.afm) file
and told the Mathematica PostScript interpreter where it can
find the AmazingFont ??
If you using the correct font name, i.e.
Graphics[Text[Hello World!, {0, 0},
                 TextStyle -> {FontFamily ->Wingdings}]] // Show
you will see it in the FrontEnd but exporting the set to PostScript
may cause problems.
Your second question is no because the kernel knows nothing about the
font metrics and can't determine the character width .. only the 
FrontEnd read the font metrics.
   Jens
> I have two questions related to fonts in graphics. First, I have a number 
of
> postscript fonts installed.  They appear as one would expect in the
> Mathematica menu under Format->Font, and also, if I use something like
 txt = StyleForm[Hello World, FontSize -> 36, FontFamily -> 
AmazingFont,
> FontWeight -> Ordinary]
> then the output appears correctly (i.e., it looks right, having the 
correct
> font) as the display value for txt. Furthermore, if I simply embrace this 
in
> Text[] such as
 Text[txt, {0,0}]
 the output shows
 Text[Hello World, {0,0}]
 again with the text of Hello World being displayed within the Notebook 
in
> AmazingFont. But when I put that Text[] into a graphic,
 Show[Graphics[Text[txt,{0,0}]]]
 the font is now substituted with Helvetica. I have used Ctrl-E to examine
> the postscript of the graphic, which confirms the Helvetica. What am I 
doing
> wrong, and please, how can I correct it?
 The second question is a repeat of one which appeared many years ago on 
the
> newsgroup (1992?) but received no reply at the time. It is this. Can one
> interrogate the font metrics from within Mathematica so that one can
> discover the dimensions of, say, the letter i in Helvetica font 14 
point.
 
> Mark R. Diamond
 
> 
===
Subject: Re: How to run/call a Mathematica Notebook from another Notebook
the classic way is to mark *all* input in notebook A and B
as initialization, when you save the notebooks, the FrontEnd will
ask you to generate a *Package* from the initialization cells
and you should say yes. Now you can call
Get[A.m];
Get[B.m]
in notebook C and you are done ...
   Jens
> HI,
 How to run/call a Mathematica Notebook from another Notebook ?
 say, I want Notebook A and B to be executed and then Notebook C. How do
> I run/call Notebooks A and B from C ?
 Prashanth
> 
===
Subject: Re: benchmark...why don't you send it back?
{MachineName -> ifbpc14, System -> Microsoft Windows, BenchmarkName ->
     2006, BenchmarkResult -> 0.643, TotalTime ->
    144.462, Results -> {{Data Fitting, 4.687}, {Digits of
   Pi, 2.003}, {Discrete Fourier Transform, 4.736}, {
   Eigenvalues of a Matrix, 9.694}, {Elementary Functions, 7.721}, {Gamma
     Function, 1.922}, {Large
   Integer Multiplication, 2.383}, {Matrix Exponential, 3.564}, {Matrix
       Multiplication, 39.017}, {Matrix Transpose,
       8.131}, {Numerical Integration, 4.897}, {Polynomial Expansion, 
6.159}, 
{Random Number Sort, 4.516}, {Singular Value Decomposition, 19.186}, 
{Solving 
a Linear System, 25.846}}, Processor -> Athlon XP 2.4 GHz,
        Memory -> 1 G, Operating System -> Windows 2000,
       SP 4, $Slaves -> $Slaves}
Ouch, mine seems a bit slow...

===
Subject: Re: Using Map with function that has options...
Each of you basically gave me a slightly different way to do the same
thing, and all those work perfectly!
Giacomo
===
Subject: perplexed by blank sequence in pattern replacement
I have been blithely using blank sequences in pattern matching for some
time. In persuit of a bug in a package of mine, I was quite alarmed to
find that I don't really understand how to use the blank sequence, as
expressed in the following simplified example:
In[1]:=Replace[a*b*c,Times[mysequence__]:>{mysequence}]
Out[1]={a b c}
I expected Out[1]={a,b,c}, from a naieve reading of the full form of
a*b*c
In[2]:=FullForm[a*b*c]
Out[2]//FullForm=Times[a,b,c]
Will someone PLEASE tell me why In[1] does not yield the results I
expected? (I can readily use a work-around, what I am concerned with is
a correct understanding of pattern matching).
Blake Laing
thesis slave
University of Oklahoma
===
Subject: Re: ListContourPlot3D and colors
> ListPlot3D, DensityPlot, ContourPlot, Raster and not for
> ListContourPlot3D (because it's Graphics3D object, not Graphics). so?
> any others sugestions?
You are right. I have been too fast to reply. Sorry about that.
There exist an option ContourStyle but I beleive that can change only
the whole color.
However, I think that the following thread will help you to define
your own color function:
ContourPlot3D and mapping,
http://forums.wolfram.com/mathgroup/archive/2005/Mar/msg00310.html
HTTTTH (Hope that this time this help :-)
Jean-Marc
===
Subject: Re: ListContourPlot3D and colors
> What about using the option ColorFunction?
> http://documents.wolfram.com/mathematica/functions/ColorFunction
maybe i'm wrong, but the ColorFunction is an option for Graphics
Objects (such as Plot3D, ListPlot3D, DensityPlot, ContourPlot...) and
not for Graphics3D Object (ListContourPlot3D). any suggestion how to
apply it with ListContourPlot3D?
===
Subject: RE:  ListContourPlot3D and colors

I would be interested if you could send me
hy all,
i have got a 3D grid of complex numbers and i want to plot isodensity
surface from it.
you can say - no problem, and i agree with this.
ListContourPlot3D[Abs[test3d]^2, Contours -> {10}]
but what i realy want is to color this surface in that way, that color
is depening of the argument of the complex value at particular point -
to do this i can use ArcColor[] - but how i can use it in
ListContoPlot3D ??
gawryl
===
Subject: Re:   Re: MemberQ
> ...
>   
>> While we are talking about MemberQ, what about the following behavior?
>> In[15]:=Range[0,1,1/10]
>>              MemberQ[Range[0,1,1/10],2/10]
>> Out[15]=!({0, 1/10, 1/5, 3/10, 2/5, 1/2, 3/5, 7/10, 
4/5, 
>> 9/10, 1})
>> Out[16]=True
>> Is the above result correct given that 2/10 doesn't appear in the list 
>> produced by the range statement??
>>     
 Mathematica automagically cancels 2/10.
   
>> On the other hand 0.5 can be
>> represented exactly as a binary number, but
>> In[29]:=MemberQ[Range[0,1,1/10],.5]
>> Out[29]=False
>>     
 1/2 has head Rational, 0.5 has got head _Real. So they must not be the 
same.
   
>> LP
>>     

> http://people.freenet.de/Peter_Berlin/Mathe/NMemberQ/NMemberQ.m
> and
> http://people.freenet.de/Peter_Berlin/Mathe/NMemberQ/NMemberQ.nb
 Feel free to add the function NMemberQ to your own collection of 
utilities.
    Peter

   
topic and will probably be interested in your function NMemberQ[]. As 
others have pointed out the use of MemberQ to compare fixed precision 
(Real) and Rational numbers produces unpredictable (machine and version 
dependent) results. My main point was that any such comparison should 
produce an error or warning that the comparison is not reliable, rather 
than True or False.
It still strikes me as strange that
In[8]:=.7//FullForm
            Range[0.,1.,.1][[8]]//FullForm
            MemberQ[Range[0.,1.,.1],.7]
Out[8]//FullForm=0.7`
Out[9]//FullForm=0.7000000000000001`
Out[10]=True
returns True for two numbers that Ma tells me are different.
Leigh
===
Subject: Re: Two strange problems with a notebook...
I'm not actually sure of what I've done, but I managed to solve the
problem converting to and from different display and/or output
formats...
Giacomo
> Sometimes notebooks get subtly corrupted. If you can read and correct
> box expressions, then you can use ctrl+shift+e on a cell and manually
> correct the problem. Otherwise, (1) copy the affected cells as plain
> text, (2) paste it into a text editor, (4) manually correct any
> problems in the text editor, (5) delete the problem cell, (6) create a
> new cell, (7) paste the text back in. If that doesn't work, manually
> retype the cell.
  > I'm been working on a Mathematica book for a lot of time, modifying it
> often and changing cell division and so on, and saving every time the
> modified version to a new file (as for now, I'm at version 23).
>  > In the last versions, I'm experiencing two strange problems:
>  > 1) There is a line in a cell that is something like this:
>  > myPath= c:myFolder
>  > When I evaluate the cell, the message windows shows the error (I'm
> reporting a cut->paste form the message window):
>  > The string '' cannot be displayed with ShowStringCharacters->False 
due
> to an error in the string.
>  > Observing the first double quote, I can notice that the space around it
> is unusual. Deleting a retyping it fixes the problem, but the next time
> I open (obviously after fixing and saving) the nb the problem is still
> there...
>  > 2) After some initialization cells, I have the main cell that does few
> operations and then  to perform two nested loops to calculate a
> evaluate the cell as is (after evaluating all the other cells),
> mathematica just skip to the end of the cell without actually exectuing
> any of the instruction in the cell.
> To fix this, it suffices that I modify the cell adding and deleting a
> carachter at any position... then I can evaluate the cell correctly.
> As before, fixing and saving doesn't solve the problem, that is there
> the next time I opne the nb...
>  > I also tried to copy all the cells to a new nb, but with no success...
>  > Any Idea about all this?
>   > Giacomo
>   
 -- 
> http://chris.chiasson.name/
===
Subject: Re:  Re: using answer form reduce
The Mathematica system is so large - I am sure they have to be very 
vigilant
to maintain their current level of cohesiveness and cross-referencing.
If you send an email to technical support about it, you can probably
persuade them to add a cross reference to ToRules to make things
better for future users.
  ToRules did the trick.
 I don't know why Reduce just does not include an link to the section 
where
> they explain ToRules, because an example using Reduce is shown there, as 
i
> saw after all the advice I got.
 Akil
 akil <akomur@wanadoo.nl> schreef in bericht
> After using reduce I get the following two types of answers:
>  > answer == Real1 || answer == Real2
> or
> answer == Real3
> , the type can change from one formula to another.
>  > I need the Reals, and put them all in a list. The problem is getting 
all
> the
> reals, without knowing which type I deal with, it should be able to be
> done
> fast.
>  > I tried making a list of the returned adres, and then using
> Cases[list, _Real, Infinity] and using Select[list,NumericQ] but both 
do
> not
> give me the answer I require.
>  > How can I get the answer I require e.g. something like 
{Real1,Real2,Real3}

http://chris.chiasson.name/
===
Subject: Re: simple question
In[17]:=
patternMatchReverse[lst_List]:=
    Flatten[Append[lst,{}]//.{x_,y___,{z___}}:>{y,{x,z}}];
In[18]:=
patternMatchReverse[Range[10]]
Out[18]=
{10,9,8,7,6,5,4,3,2,1}
dkr
===
Subject: Re:  simple question
 I know it is simple but I can't find something.
 In[1]:= lst=Range[10]
> Out[1]= {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
 In[2]:= Reverse[lst]
> Out[2]={10, 9, 8, 7, 6, 5, 4, 3, 2, 1}
 How we can get the same result with pattern matching?
 My unsuccesful attempts include
 In[9]:=Range[10]/.{x_,y___}->{y,x}
 Out[9]={2, 3, 4, 5, 6, 7, 8, 9, 10, 1}
 In[10]:=
> Range[10]//.{x_,y___}->{y,x}
 ReplaceRepeated::rrlim: Exiting after !({1, 2, 3, 4, 5, 6, 7, 
8,
> 9, 
> 10}) scanned !(65536) times.
 Out[10]=
> {7, 8, 9, 10, 1, 2, 3, 4, 5, 6}
 Can I add something to previous rules to work?

One way is:
lst=Range[10];
lst//.{a___,x_,y_,b___}/;OrderedQ[{x,y}]:>{a,y,x,b}
{10,9,8,7,6,5,4,3,2,1}
but you should be aware that this is a very inefficient way to  
achieve this result.
Andrzej Kozlowski
===
Subject: Re: simple question
((Range[10] /. lst_ :> {
           lst, {}}) //. {{a_, b__}, {c___}} :> {{b}, {a, c}}) // Flatten
if you wish to remove the last Flatten[] you can try
(((Range[10] /. lst_ :> {lst, {}}) //.
               {{a_, b__}, {c___}} :> {{b}, {a, c}})) /.
               {{a_}, {c__}} :> {a, c}
   Jens
 I know it is simple but I can't find something.
 In[1]:= lst=Range[10]
> Out[1]= {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
 In[2]:= Reverse[lst]
> Out[2]={10, 9, 8, 7, 6, 5, 4, 3, 2, 1}
 How we can get the same result with pattern matching?
 My unsuccesful attempts include
 In[9]:=Range[10]/.{x_,y___}->{y,x}
 Out[9]={2, 3, 4, 5, 6, 7, 8, 9, 10, 1}
 In[10]:=
> Range[10]//.{x_,y___}->{y,x}
 ReplaceRepeated::rrlim: Exiting after !({1, 2, 3, 4, 5, 6, 7, 
8,
> 9, 
> 10}) scanned !(65536) times.
 Out[10]=
> {7, 8, 9, 10, 1, 2, 3, 4, 5, 6}
 Can I add something to previous rules to work?
 
===
Subject: Re:  simple question
Range[10]//.{s___,x_,y_,e___}/;y>x:>
    {s,y,x,e}
{10,9,8,7,6,5,4,3,2,1}
Bob Hanlon
 I know it is simple but I can't find something.
 In[1]:= lst=Range[10]
> Out[1]= {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
 In[2]:= Reverse[lst]
> Out[2]={10, 9, 8, 7, 6, 5, 4, 3, 2, 1}
 How we can get the same result with pattern matching?
 My unsuccesful attempts include
 In[9]:=Range[10]/.{x_,y___}->{y,x}
 Out[9]={2, 3, 4, 5, 6, 7, 8, 9, 10, 1}
 In[10]:=
> Range[10]//.{x_,y___}->{y,x}
 ReplaceRepeated::rrlim: Exiting after !({1, 2, 3, 4, 5, 6, 7, 
8,
> 9, 
> 10}) scanned !(65536) times.
 Out[10]=
> {7, 8, 9, 10, 1, 2, 3, 4, 5, 6}
 Can I add something to previous rules to work?
 
--
Bob Hanlon
hanlonr@cox.net
===
Subject: Product over an arbitrary index.
I have a function f(x,y)   that I would like to compute the product
over indices i,j
where i goes from an arbitrary list {1,4,3}  and j goes 1 to m.
Is this possible in mathematica the function Product itself seems to
only work over a continous sequence and it is not clear how I can use
two set of indices.
Additionally can I specify the product over an intersection or
complement of a list?.
K Frou
===
Subject: namespace collision [bug]
As far as I know, a named pattern created inside the A`Private`
context should not interfere with the definition of a symbol with the
same name from B`. Will someone verify this as a bug? Will someone
please provide a workaround?
In[1]:=
BeginPackage[A`];
funA::usage=;
Begin[Private`];
funA[funB_]:=funB!;
End[];
EndPackage[];
BeginPackage[B`];
Off[General::spell1];
funB::usage=;
funC::usage=;
Begin[Private`];
funB[_]:=you called funB;
funC[_]:=you called funC;
End[];
EndPackage[];
In[16]:=
funB[5]
Out[16]=
funB[5]
In[17]:=
funC[5]
Out[17]=
you called funC
In[18]:=
$Version
Out[18]=
5.2 for Microsoft Windows (June 20, 2005)
-- 
http://chris.chiasson.name/
===
Subject: Re: Solving integrals
> sorry, this post apparently got mangled (åÓ aka 
^2 wasn't recognized).
> Here is the integral again:
 f := int ( cos(x) / sqrt[ A*A*sin(x/2)*sin(x/2) + (Bx)^2] dx, x=0..N*2*pi
 where N==(int)0..20, and A and B are small fixed values (around
> 0.0001..0.05).
 
Hello everybody,
since I've been told by email a number of times:
yes, I know this integral has a singularity. However, it represents a
physical measure (so it must exist), and a simpler form (without the (Bx)^2
in the denominator) can be and has been solved via conversion to Elliptic
Integrals.
I'm just at a los as how to split this one up.
Please help me a bit :)
-- 
Jens Benecke
===
Subject: Re: Solving integrals
> Hello everybody,
>> I am trying to solve this integral:
>> f :== int ( cos(x) / sqrt[A=C2=B2=C2=B7sin=C2=B2(x/2) + (Bx)=C2=B2 =
>> ] dx, x==0..N*2*pi
 
> sorry, this post apparently got mangled (Ó aka ^2 
wasn't recognized).
> Here is the integral again:
 f := int ( cos(x) / sqrt[ A*A*sin(x/2)*sin(x/2) + (Bx)^2] dx, x=0..N*2*pi
 
>> where N==(int)0..20, and A and B are small fixed values (around
>> 0.0001..0.05).
...
> 
Hi Jens,
  sorry, your integral does not converge on the interval [0, something], 
because your integrand is c_(-1)*x^(-1) + c_(1)*x + ... near x=0:
expr = Cos[x]/Sqrt[(a*Sin[x/2])^2 + (b*x)^2];
Normal[Simplify[Series[expr, {x, 0, 1}], a > 0 && b > 0]]//InputForm
Out[2]//InputForm=
  2/(Sqrt[a^2 + 4*b^2]*x) +
   ((-11*a^2 - 48*b^2)*x)/(12*(a^2 + 4*b^2)^(3/2))
Peter
===
Subject: distance function
In the book of Gaylord et al. (1996) there is one exercise which asks
(see page 113)
Given a list of points in the plane, write a function that finds the
set of all distances
between the points.
Although there is one solution, that solution makes use of the Table
and Length commands.
Is it a way to define the same function using Higher-Order functions
like Outer, MapThread etc?
===
Subject: too many special linear matrices
In an old group theory book they talk about special linear groups over 
the modulo  of prime
Integers: SL[2,P]
The formula given is
number of matrices in the group  =If [n=2,6,Prime[n]*(Prime[n]^2-1)]
(Essentual Student Algebra, Volume 5 ,Groups, T.S. /Blyth and E.F. 
Robertson,1986, Chapman and Hall,New York, page 14)
So I tried to  generate the elements of the group in Mathematica by a 
search program for Determinant one
matrices.
I get:
6,24,124,348
instead of what I should get:
6,12,60,168
Since the famous Klein group SL[2,7] is one of these ,
it would help to have a set of elements for that group!
Mathematica code:
Clear[M, k, s]
M = {{l, m}, {n, o}};
k = 3
s = 
Union[Delete[Union[Flatten[Table[Flatten[Table[Table[If[Mod[Abs[Det[M]],  
k] - 1 == 0, M , {}], {l, 0,k - 1}], {m, 0, k - 1}], 1], {n, 0, k - 1}, 
{o, 0, k - 1}], 2]], 1]]
Dimensions[s]
===
Subject: position lists
have
  In: a = {1, 1, 2, 2, 1, 4}
want
  {{1, 2, 5}, {3, 4}, {0}, {6}};
more effectively than just
  In: Position[a, #] & /@ Range[4]
  Out: {{{1}, {2}, {5}}, {{3}, {4}}, {}, {{6}}}
Ideas? Known one-liners?
Igor
===
Subject: FileNames subdirectory count discrepancy
from the help:
FileNames[forms, dirs, n] includes files that are in subdirectories up
to n levels down.
why does a file that is only one level down require n=2?
In[1]:=
FileNames[system.ini,{C:},1]
Out[1]=
{}
In[2]:=
FileNames[system.ini,{C:},2]
Out[2]=
{C:WINDOWSsystem.ini}
In[3]:=
$Version
Out[3]=
5.2 for Microsoft Windows (June 20, 2005)
-- 
http://chris.chiasson.name/
===
Subject: Re: No output or In[n] prompt appearing
>I have this weird problem. When I enter anything as simple as
>2+2
>and shift+Enter, there is no error or anything. It seems that the
>cell is evaluated, but nothing shows up, not even the In[1] prompt.
The only way I know to get a result like you describe is when there is no 
Kernel running.
Look at the menu item, Kernel->Default Kernel. Is None checked? If so, that 
would explain your result. This can be corrected by selecting Kernel->Default 
Kernel->Local which will cause the local kernel to be started on after the 
first shift+Enter.
--
To reply via email subtract one hundred and four