## Bug in procedure writefile of Maple9...

I think I have found a subtle bug in my Maple 9.

If I execute the following code:

###
B:=[ 3.5, 0.0001, 73.45]; A:=[[seq(1/op(j,B), j=1..3)]];
writedata("a.txt",A);
###

the output file a.txt contains the line
0.2857142857    1       0.01361470388
(beware: maple has written "1" instead than "10000"!)

Questions:
1) is this bug already known? Is there a patch?
2) does it affect newer versions of Maple?

## Operations on entries of an array...

I would like to perform some operations on all the entries of an array (or an all entries in some given rows/columns).
Can this be achieved without writing an ad hoc loop?
(for instance this task is extremely easy in octave/matlab)
Should I use some specific package?

## Plotting binary trees...

I have some data which have a binary tree structure.

Is there a simple way to plot (at least partially) my binary tree?

## Boolean evaluation...

In Maple boolean evaluation returns the values 'true' or 'false'.

Is there any canonical way of getting evalb to produce values in {0,1}? This is of some use when testing conjectures on  hudge lists of items...

Of course: you can always define a script like

###########################
evalbb:=proc(PP)
if evalb(PP)='true' then eps:=1:
else eps:=0:
fi:
eps;
end:
###########################

but I think there should be...

## Find the width of a plot...

Hi all,

Is there some way i can find the width of a plot?

I have the equation below:

Prob:=(w,T)->(B^2)*(sin(w*(T/2))^2)/((w/2)^2);

plot(Prob(w,6),wf=-3..3);

Which produces a gaussian looking plot, the plot reaches zero at some...

## 1-D box, supressing output...

Hi, Im trying to show the first few energy levels of a particle in a 1-D box. The plots are looking how i want them to look, but i can't stop it from producing loads of unwanted code. It seems to have been produced from P1 and P2 and putting a colon after them doesn't supress the output.

Can anyone see how i can stop the blue code from being shown and keep the plots?

## How do I extract the Imaginary part of a complex n...

Im quite new to Maple, how do I extract the imaginary part of sqrt(I)? Im sure it is just Im(sqrt(I)) and Re(sqrt(I)), but the Im part just returns the real part againg for some reason, does anyone know what I am doing wrong here?

I'm using maple 9 by the way

>sqrt(I);

## Maple 9 compatibility issues with Windows 7...

I cannot get Maple 9 Student Edistion to run in Windows 7. I've tried running it in compatibility mode, but it still doesn't work. Are there any software updates or patches available? Is there another Solution?

## how to use correctly assumptions about Matrix elem...

Dear All,

I would like to make assumptuions about the input parameters of a procedure. The input parameter of the procedure should be the (1,1) element of a 2-dimensional Matrix. I make the same assumptions for the elements of the Matrix as expected by the procedure. When I  call he procedure with the (1,1) element of the matrix, it gives the following error. How should I use the assumptions or how to pass correctly the parameter to the procedure in this particular case?

## Error, (in Convert) unable to convert...

Hi,

I would like to differentiate a sinlge-variable function containing abs(), min(), and max() calls. For smaller functions it seems to work, however for my procedure, it does not seem to work. What can be the problem? I would appreciate any comment.

It seems to work for the followings:

> diff(min(5*x,3),x);
/        ...

## Lottery...

In the Belgium lottery they pick 6 numbers out of 42   (  there can't be 2 equals numbers being picked out )
Now for my maple homework , i must do some exercices in maple

1 ) Simulate the lottery
2 ) If you partici

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