## Why doesn't evalf work on data structures like Mat...

Why doesn't evalf work on the data structures below?

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## How to evaluate definite integral without substitu...

i am trying to solve definite integral but i want result in A,B form i dont want to assign numerical values to them can i get that  in maple? i have tried evalf, eval and simplify command but it is not working kindly help me out

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## File preview in File Explorer of Windows...

I was wondering if this has ever been discussed?

File preview would make life easier when searching an older document.

Since it seems to be a non trivial programming task, I was wondering whether generating a pdf document in parallel to a worksheet could be an option (in a subfolder). However, doing this by hand for all existing documents is not pratical.

Could this (generating pdf files) be done by a batchjob?

## Why does sqrt(-2) give only i*sqrt(2) as a result ...

Why does sqrt(-2) give as a result only i*sqrt(2)?

Why does the result not also include -i*sqrt(2)?

## calling a maple code from python...

How to Call a maple code from inside a python code in jupyter say or sypder.

## How can I find a values of the coefficients in pol...

I tried to solve a equation f(x). Finally I got a polynomial with coefficients.  (see Solve_for_coefficients.mw)

I want to find the values of unknown coeffients in the last polynomial equation as procedure to equating each cofficients to zero.

For example, the coefficients of x^2 is 1/48*(-24*p[2]+48*q[1]+24*q[2]+24) = 0.

Likewise, collect all the coefficients from x^0 to x^4 and solve them. Finally we get the coefficients value.

My question is How to collect the coefficients in this polynomial and solve this coefficients?

## convert equation???...

Hi,

How do we get from equation 11 to equation 13 with Maple by converting equations 12?

## partition with fixed size and maximum value...

Hello

I would like to calculate the number of partitions of a number s with length n, where the maximum value in the partitions is also n.

For example: s=10, n=4

The result should be 5, because there are 5 partions with length 4 and maximum value 4:

4411, 4321, 4222, 3331, 3322

If I use "PartitionFixedSize(10,'parts'=4)", it makes also partitions with values > 4, for example 5311. How to limit this?

Kind regards

 >

## How to do something similar to subsop(index=value,...

Suppose we have the following simple Matrix

T := <1,2;3,4>;

How do we replace an entry with another expression?

I know that for a list L := [1,2,3] we can do, for example subsop(2=500,L) to replace the entry at index 2.

This creates a new list since lists are immutable.

As far as I can tell, a Matrix is mutable.

However, I wish to change an entry in a Matrix without mutating it.

My actual use case is the following.

I use LinearAlgebra:-Eigenvectors to obtain a Matrix of eigenvectors. Some of the entries are huge expressions with many variables. I would like to sub in placeholders where these huge expressions are so I can visualize the Matrix better, but without modifying the original Matrix.

## Convert existing worksheet to document mode...

Is it possible to  convert an existing document in worksheet mode to document mode in Maple22 ?

It seems you can only select either at creation of document but not convert documents already existing.

## Problem using smart plot with multiple solutions ...

I switched to using smart plot in Maple since it makes it easier. Here is an example

```sol:=[-1/4*x^2, x];
plot(sol,legend=sol)
```

But sometimes it gives internal error, like in this example, because some of the list of solutions give complex over some x domain

```sol:=[-1/4*x^2, (-1/2-1/2*(-3)^(1/2))^2+(-1/2-1/2*(-3)^(1/2))*x, (-1/2+1/2*(-3)^(1/2))^2+(-1/2+1/2*(-3)^(1/2))*x];
plot(sol,legend=sol)
```

Luckily I can trap this error and workaround it.

The strange thing is that if I give it explicit x range, then it works. It now can remove the solutions which give complex values automatically

```p:=plot(sol,x=-4..4,legend=sol);
```

question is: Should not smart plot have done this automatically? That is why it is called smart plot.

i.e. remove those solutions that give complex values like the case the above?

Maple 2024.1 on windows 10

## How do I test if a variable t is in a definite ope...

I want to define a piecewise function. How do I test if a variable t is in a definite open or closed real range?

## why maple hangs on this plot command?...

I am using the smart plot (i.e plot without giving the x=from..to) since I am generating these plots programmatically and better let Maple figure the best range to use.

But found Maple hangs on some solutions.

Here is an example

```restart;
sol:=1/2/cos(x)*(sin(x)^2+(sin(x)^4+36*cos(x))^(1/2));
plot(sol);
```

I waited for 30 minutes and nothing happened.

If I change the above command to

`plot(sol,x=-Pi..Pi);`

then it finishes instantly. It looks like Maple is stuck trying to find correct x and y ranges to use.

Is this known limitation  or smart plot or is this a bug?

Maple 2024.1 on windows 10.

## How to use d_[] ? ...

What exactly is the difference between the differential operator d_[] from the physics package and diff() ? Why is it not possible for me to differentiate a scalar function g or a coordinate r with the help of the operator? d_[1] should correspond to d/dx (X = (x, y, z, t)) or not?

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## plot solution of PDE ...

```restart;
with(Plot);
params := {alpha = 2.5, k = 3, w = 2, beta[3] = 3, beta[4] = 1.7};
xi := beta[3]*(2*alpha*k*t + x)*sqrt(1/(36*alpha*beta[4] + 36*gamma*beta[4]));
params := {alpha = 2.5, k = 3, w = 2, beta[3] = 3, beta[4] = 1.7}

xi := beta[3] (2 alpha k t + x)

(1/2)
/                 1                 \
|-----------------------------------|
\36 alpha beta[4] + 36 gamma beta[4]/

sol1n := u(x, t) = U(xi)*exp((-sqrt(1/(36*alpha*beta[4] + 36*gamma*beta[4]))*x + w*t + theta)*I);
/
|
sol1n := u(x, t) = U|beta[3] (2 alpha k t + x)
\

(1/2)\    /  /
/                 1                 \     |    |  |
|-----------------------------------|     | exp|I |
\36 alpha beta[4] + 36 gamma beta[4]/     /    \  \
(1/2)                \\
/                 1                 \                     ||
-|-----------------------------------|      x + w t + theta||
\36 alpha beta[4] + 36 gamma beta[4]/                     //

plot3d(rhs(sol1n), x = 0 .. 250, t = 0 .. 4);
```

how plot the the solution of PDE of this kind of function?