## 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?

Thank you for an answer!

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?

 (1)

 (2)

 (3)

 (4)

 (5)

 (6)

 (7)

 (8)

## 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?

## How to use animate (or explore) function to plot t...

Hello

Here is the ODE

`sys := {diff(w(t), t) = y(t)*z(t), diff(x(t), t) = a*w(t), diff(y(t), t) = x(t)*z(t) + w(t), diff(z(t), t) = -x(t)*y(t), w(0) = w0, x(0) = x0, y(0) = y0, z(0) = z0}`

with initial parameters a=2, w0 = -0.727367040, x0 = -0.728244724, y0 = -0.237753623 and z0 = 0.014225402.

With these parameters I have no problem to plot the solution.

```nsys := subs({a=2,w0 = -0.727367040, x0 = -0.728244724, y0 = -0.237753623, z0 = 0.014225402},sys);

numsol := dsolve(nsys, numeric, method = rkf45);

vars:=[x,y,z,w];

with(plots):

col := [red, magenta, cyan, blue]:
display(
seq(
plots:-odeplot(numsol, [t, vars[i](t)], t=0..3, color=col[i], legend=vars[i](t))
, i=1..numelems(vars)
)
)
```

How to use animate (or explore?)  with a slider for each parameter (a,x0,y0,z0,w0)? And if I want to add a tfinal as well for the simulation (in place of 3)? ( I am newbie as far as using plot and related functions in Maple).

Many thanks.

## what causes kernel connection not available somet...

sometimes (not often) I get this pop-up window when I open new worksheet and run something first time in it.

And it can last for 10-20 seconds until connection is made.

I have my preferences set to  create new engine for each worksheet.

The strange thing when this happened now, is that I only had 4 worksheets open and was not running anything in any of them. So Maple was not "busy". Task manage showed 8 mservers.exe processes on it at the time. Which is not unormal.

I have 128 GB and PC was not busy at the time this happened.

Any idea what can cause this to happen?

Windows 10 home edition, Maple 2024.1

## How to obtain the extent of the x and y axis used ...

When making this plot, using smart plot (i.e. not giving the plot command the x=from..to and also not giving it y=from...to

`p:=plot(0,color=red);`

I need to programatically find the x=-10..10 and y=-1..1 from the variable p. But if I do

`rhs~(indets(p, identical("originalview")=anything));`

it gives

{[-10. .. 10., 0. .. 0.]}

But clearly looking at the plot the y axis is from -1..1

The reason I need to determine the view from the above plot, is that I need to use same view windows size in another plot not using smart plot (phase plot) which requires one to provide explicit x and y ranges. i.e I'd like the phase plot to have same view size in terms of x range and y range.

I printed the PLOT structure but do not see another field to look at.

Any idea or trick to find y=-1..1 values in this example ? I am using Maple 2024.1

```lprint(p)
PLOT(CURVES(Matrix(200,2,{(1, 1) = -10., (2, 1) = -9.89484789949749, (3, 1) =
-9.80335561909548, (4, 1) = -9.70046298090452, (5, 1) = -9.59688830351759, (6,
1) = -9.49380589849246, (7, 1) = -9.39823531356784, (8, 1) = -9.29927750854271,
(9, 1) = -9.19693520502513, (10, 1) = -9.09492111457286, (11, 1) =
-8.98998708341709, (12, 1) = -8.89756113165829, (13, 1) = -8.79351140100503, (
14, 1) = -8.6890344321608, (15, 1) = -8.58835151356784, (16, 1) =
-8.49692177788945, (17, 1) = -8.38820297889447, (18, 1) = -8.29610389547739, (
19, 1) = -8.18897076683417, (20, 1) = -8.09413979497487, (21, 1) =
-7.99009518894472, (22, 1) = -7.89102011959799, (23, 1) = -7.78764567839196, (
24, 1) = -7.69271567135678, (25, 1) = -7.59032083417085, (26, 1) =
-7.4839613758794, (27, 1) = -7.39137515477387, (28, 1) = -7.29137949949749, (29
, 1) = -7.18807420301508, (30, 1) = -7.08701012462312, (31, 1) =
-6.9892254321608, (32, 1) = -6.88065220301508, (33, 1) = -6.78309432763819, (34
, 1) = -6.67893047236181, (35, 1) = -6.58454253768844, (36, 1) =
-6.48135159396985, (37, 1) = -6.38425695778894, (38, 1) = -6.28276508643216, (
39, 1) = -6.18353823115578, (40, 1) = -6.07965690954774, (41, 1) =
-5.97960685025126, (42, 1) = -5.87729121407035, (43, 1) = -5.77582280301507, (
44, 1) = -5.68258387135678, (45, 1) = -5.57572153366834, (46, 1) =
-5.48014258492462, (47, 1) = -5.37823549045226, (48, 1) = -5.28069739798995, (
49, 1) = -5.17239388140703, (50, 1) = -5.07861099396985, (51, 1) =
-4.97216657788945, (52, 1) = -4.87515404824121, (53, 1) = -4.76903758693467, (
54, 1) = -4.67747702713568, (55, 1) = -4.57320023718593, (56, 1) =
-4.47247400603015, (57, 1) = -4.37181357688442, (58, 1) = -4.27152345929648, (
59, 1) = -4.17517605326633, (60, 1) = -4.07102195577889, (61, 1) =
-3.97175554874372, (62, 1) = -3.86728232964824, (63, 1) = -3.77270890854271, (
64, 1) = -3.66818757386935, (65, 1) = -3.56807434874372, (66, 1) =
-3.46820480201005, (67, 1) = -3.36389067336683, (68, 1) = -3.26781355276382, (
69, 1) = -3.16941743919598, (70, 1) = -3.06077643819095, (71, 1) =
-2.96241091055276, (72, 1) = -2.86181373366834, (73, 1) = -2.7595089959799, (74
, 1) = -2.66547103417085, (75, 1) = -2.5652296120603, (76, 1) =
-2.46575123417085, (77, 1) = -2.35934029145729, (78, 1) = -2.26543724422111, (
79, 1) = -2.15709262110553, (80, 1) = -2.05931995175879, (81, 1) =
-1.96257900603015, (82, 1) = -1.85855141105528, (83, 1) = -1.75410300301508, (
84, 1) = -1.65907041708543, (85, 1) = -1.5581500321608, (86, 1) = -1.4596616, (
87, 1) = -1.35289910050251, (88, 1) = -1.26051985527638, (89, 1) =
-1.15441893366834, (90, 1) = -1.05467848944724, (91, 1) = -.955901429145728, (
92, 1) = -.857045790954773, (93, 1) = -.756219297487437, (94, 1) =
-.649344903517589, (95, 1) = -.551351549748743, (96, 1) = -.454619526633167, (
97, 1) = -.351214585929648, (98, 1) = -.248034748743718, (99, 1) =
-.155424717587939, (100, 1) = -.0457214572864313, (101, 1) = .0460731437185924,
(102, 1) = .153437240201004, (103, 1) = .255905869346734, (104, 1) =
.347398149748743, (105, 1) = .4502907879397, (106, 1) = .553865465326634, (107,
1) = .656947870351759, (108, 1) = .752518455276382, (109, 1) = .851476260301508
, (110, 1) = .953818563819095, (111, 1) = 1.05583265427136, (112, 1) =
1.16076668542714, (113, 1) = 1.25319263718593, (114, 1) = 1.3572423678392, (115
, 1) = 1.46171933668342, (116, 1) = 1.56240225527638, (117, 1) =
1.65383199095477, (118, 1) = 1.76255078994975, (119, 1) = 1.85464987336683, (
120, 1) = 1.96178300201005, (121, 1) = 2.05661397386935, (122, 1) =
2.1606585798995, (123, 1) = 2.25973364924623, (124, 1) = 2.36310809045226, (125
, 1) = 2.45803809748744, (126, 1) = 2.56043293467337, (127, 1) =
2.66679239296482, (128, 1) = 2.75937861407035, (129, 1) = 2.85937426934673, (
130, 1) = 2.96267956582914, (131, 1) = 3.06374364422111, (132, 1) =
3.16152833668342, (133, 1) = 3.27010156582915, (134, 1) = 3.36765944120603, (
135, 1) = 3.47182329648241, (136, 1) = 3.56621123115578, (137, 1) =
3.66940217487437, (138, 1) = 3.76649681105528, (139, 1) = 3.86798868241206, (
140, 1) = 3.96721553768844, (141, 1) = 4.07109685929648, (142, 1) =
4.17114691859297, (143, 1) = 4.27346255477387, (144, 1) = 4.37493096582915, (
145, 1) = 4.46816989748744, (146, 1) = 4.57503223517588, (147, 1) =
4.6706111839196, (148, 1) = 4.77251827839196, (149, 1) = 4.87005637085427, (150
, 1) = 4.97835988743719, (151, 1) = 5.07214277487437, (152, 1) =
5.17858719095477, (153, 1) = 5.27559972060302, (154, 1) = 5.38171618190955, (
155, 1) = 5.47327674170854, (156, 1) = 5.57755353165829, (157, 1) =
5.67827976281407, (158, 1) = 5.7789401919598, (159, 1) = 5.87923030954774, (160
, 1) = 5.97557771557789, (161, 1) = 6.07973181306533, (162, 1) =
6.1789982201005, (163, 1) = 6.28347143919598, (164, 1) = 6.37804486030151, (165
, 1) = 6.48256619497488, (166, 1) = 6.5826794201005, (167, 1) =
6.68254896683417, (168, 1) = 6.78686309547739, (169, 1) = 6.8829402160804, (170
, 1) = 6.98133632964824, (171, 1) = 7.08997733065327, (172, 1) =
7.18834285829146, (173, 1) = 7.28894003517588, (174, 1) = 7.39124477286432, (
175, 1) = 7.48528273467337, (176, 1) = 7.58552415678392, (177, 1) =
7.68500253467337, (178, 1) = 7.79141347738694, (179, 1) = 7.88531652462311, (
180, 1) = 7.9936611477387, (181, 1) = 8.09143381708543, (182, 1) =
8.18817476281407, (183, 1) = 8.29220235778895, (184, 1) = 8.39665076582915, (
185, 1) = 8.49168335175879, (186, 1) = 8.59260373668342, (187, 1) =
8.69109216884422, (188, 1) = 8.79785466834171, (189, 1) = 8.89023391356784, (
190, 1) = 8.99633483517588, (191, 1) = 9.09607527939699, (192, 1) =
9.1948523396985, (193, 1) = 9.29370797788945, (194, 1) = 9.39453447135678, (195
, 1) = 9.50140886532663, (196, 1) = 9.59940221909548, (197, 1) =
9.69613424221106, (198, 1) = 9.79953918291458, (199, 1) = 9.9027190201005, (200
, 1) = 10.},datatype = float[8],storage = rectangular,order = Fortran_order,
shape = []),COLOUR(RGB,.47058824,0.,.54901961e-1,_ATTRIBUTE("source" =
"mathdefault"))),AXESLABELS("",""),VIEW(-10. .. 10.,DEFAULT,_ATTRIBUTE("source"
= "mathdefault")),_ATTRIBUTE("input" = [table([(1)=plot,(2)=[0]]),
"originalview" = [-10. .. 10., 0. .. 0.], "originalaxesticks" = AXESTICKS(
DEFAULT,DEFAULT,_ATTRIBUTE("source" = "mathdefault"))]))

```

Update

This below is a proc that takes PLOT data struct and returns correct x,y ranges.  It seems to work ok on few tests I did. Bug reports are welcome.

 > restart;
 > #gets a PLOT struct and returns correct x,y ranges get_x_y_range:=proc(p)::list; local T,from_x,to_x,from_y,to_y;    try       T:=plottools:-getdata(p,'rangesonly');    catch:       error StringTools:-FormatMessage( lastexception[2..-1] );    end try;   from_x := op(1,T[1]);   to_x   := op(2,T[1]);   from_y := op(1,T[2]);           to_y   := op(2,T[2]);                  if from_y=to_y then      if from_y<0 then         to_y   := 0;                         from_y := from_y-abs(from_y)/2;      elif from_y>0 then                              from_y := 0;         to_y   := to_y+to_y/2;     else         from_y := -1;         to_y   := 1;                     fi;                fi;   RETURN([from_x..to_x,from_y..to_y]);              end proc:
 > p := plot(6); get_x_y_range(p)

 > p := plot(-3); get_x_y_range(p)

 > p := plot(0); get_x_y_range(p)

 > p := plot(x); get_x_y_range(p)

 > p := plot(sin(x)); get_x_y_range(p)

 > p := plot(exp(x)); get_x_y_range(p)

 >

Update

Warning.  plottools:-getdata(p,'rangesonly') is buggy. I replaced this with

rhs~(indets(p, identical("originalview")=anything))[];

which gives more accurate Y ranges used. Here is example showing that getdata(p,'rangesonly') returns wrong y ranges for a plot compared to how it shows on the screen, So in the function above, better use the second method instead. This whole getdata(p,'rangesonly'); should be looked at by Maplesoft and fix to make it return correct values that agrees with screen view.

 > sol:=1/2/cos(x)*(sin(x)^2+(sin(x)^4+36*cos(x))^(1/2)); p:=plot(sol,x=-3..3);

 > plottools:-getdata(p,'rangesonly'); #WRONG y values compared to the above plot

 > rhs~(indets(p, identical("originalview")=anything))[]; #better result compared to plot (still not exact but better).

 >

## Problem with Excel and Maple 2024...

Hi

I teach Pre-Calulus High School level, and our school recently upgraded to Maple 2024. Like in Maple 2023 we use Assistant-Tools-import DATA and chosing an Excel file from which to import to do regression on.  In the new 2024 we have experienced, that Maple cannot read in DATA, meaning it cannot read column of DATA into a Maple document. However if we copy into Excel document on the machine locally, then there is no issue and the data is imported.

Any idear what can cause this?