MaplePrimes Questions

Hi,

Would someone please help me with how to achieve this cool animation shown here.

3d plot

How i can add lebel inside graph  like this picture for some graph , in somecoding i have but i can't how it work i want add to  my code but i can't do the same as paper did

label.mw

I am trying to find the most compact form of the symbolic matrix exponential of the specific 4x4 input matrix with the following form:

where all variables are non-negative real constants, with the additional problem specific conditions:

1. omega__1 + omega__2 = 1 

2. f__p + f__d1 + f__d2 = 1

There are many mathematically identical subterms at the matrix exponential, so I would like to use a few proper substitute subexpressions, but Maple does not apply it, without any error or warning message.

Moreover, I have no idea how to incorporate above-mentioned additional conditions into the simplification process.

expFT_compact.mw

I will be very happy for any help with this problem.

Michal

I am very interested in problems of integration and limit determination. In order to be able to continue other work with the help of Maple, I would like some advice on solving the following problem. The solution I know of using pen and paper is very tiring, perhaps Maple can make it easier:

To calculate Int(from 0 to 1)[ln(x)*ln(1-x)]dx
or, for obvious reasons, formulated differently:
Let eps, delta>0. Calculate
lim(eps, delta-->0)Int(0+eps to 1-delta)[ln(x)*ln(1-x)]dx

Is there a good way to include subscript(s) to a letter within a 'text' command?  Currently I do this by specifying the coordinates, letter, and font for the letter, then specify the coordinates, number and font for the subscript.  However, with this method the letter and subscript can be compressed if the viewing interval is compressed or expanded.  

Is there another way to include letters with a subscript in a text command?

Hi! A basic issue.

Why view=[-2 ..1, -2 ..5]  is not useful here? According to the output, only the green line meets the view settings. I want to extend the left side of these three lines appropriately (show the intersection)

with(plots)

l := 2*x+y+1 = 0; l1 := 4*x+2*y+2 = 0; l2 := 4*x+2*y-2 = 0; l3 := 4*x-2*y+6 = 0

2*x+y+1 = 0

 

4*x+2*y+2 = 0

 

4*x+2*y-2 = 0

 

4*x-2*y+6 = 0

(1)

 

display({implicitplot(l, color = black, legend = l, thickness = 5, view = [-2 .. 1, -2 .. 5])}, {implicitplot(l1, color = red, legend = l1, view = [-2 .. 1, -2 .. 5])}, {implicitplot(l2, color = blue, legend = l2, view = [-2 .. 1, -2 .. 5])}, {implicitplot(l3, color = green, legend = l3, view = [-2 .. 1, -2 .. 5])})

 
 

NULL

Download The_intersection_parallelism_and_coincidence_of_two_straight_lines.mw

I have an epidemic model and the endemik equilibrium point contains rootOf _Z, here's one of the example

i still don't understand about the _Z and find the "remove_RootOf" command. Does it affect the result or is it an explicit result of Z?

Hi,

I'm trying to use the Explore command to examine the effect of two parameters (mu and sigma) on the density function curve. The visualization isn't very optimal, especially with the mu parameter, and it's difficult to add options (range, color, gridlines, etc.). Any suggestions to optimize this idea? Thanks for your insights!

Q_Explore.mw

when we have ode equation we say what is type of equation then  i want solve by this method say the name of method and if possible i want to solve this equation by the method step by step too, maple can do that? also can we plot the solution or any geometricall presentation , also i have error in writing exact form of equation

restart

"with(Student[ODEs]): "

with(DETools)

ode1 := diff(y(x), x)+2*x*y(x) = x

diff(y(x), x)+2*x*y(x) = x

(1)

Type(ode1)

{linear, separable}

(2)

W := dsolve(ode1)

y(x) = 1/2+exp(-x^2)*c__1

(3)

odetest(W, ode1)

0

(4)

ODESteps(ode1)

"[[,,"Let's solve"],[,,(ⅆ)/(ⅆx) y(x)+2 x y(x)=x],["•",,"Highest derivative means the order of the ODE is" 1],[,,(ⅆ)/(ⅆx) y(x)],["•",,"Separate variables"],[,,((ⅆ)/(ⅆx) y(x))/(2 y(x)-1)=-x],["•",,"Integrate both sides with respect to" x],[,,∫((ⅆ)/(ⅆx) y(x))/(2 y(x)-1) ⅆx=∫-x ⅆx+`c__1`],["•",,"Evaluate integral"],[,,(ln(2 y(x)-1))/2=-(x^2)/2+`c__1`],["•",,"Solve for" y(x)],[,,y(x)=((e)^(-x^2+2 `c__1`))/2+1/2]]"

(5)

ode2 := (sin(x)*tan(x)+1)*dx-cos(x)*sec(y(x))^2*dy = 0

(sin(x)*tan(x)+1)*dx-cos(x)*sec(y(x))^2*dy = 0

(6)

Type(ode2)

Error, (in Student:-ODEs:-Type) could not determine the solving variable. Please specify it as an extra argument in the form: y(x)

 
 

NULL

Download ode-example.mw

i want try all number to my parameter for check the shape of plot there is any way for doing that?

restart

with(plots)

M := 4*b^2*beta*((a*y-2*alpha*t+x)*b^2+a*(-2*beta*t+a*(a*y-2*alpha*t+x)))/(-b^6*beta*y^2+(-4*t*y*beta^2+(-2*a^2*y^2+(4*(alpha*t-(1/2)*x))*y*a-4*(alpha*t-(1/2)*x)^2)*beta+3*a)*b^4+(-4*t^2*beta^3+4*a*t*(a*y-2*alpha*t+x)*beta^2-a^2*(a*y-2*alpha*t+x)^2*beta+6*a^3)*b^2+3*a^5)

alpha = 1; beta := 1; a := -1; b := -2; t := 0

alpha = 1

 

1

 

-1

 

-2

 

0

(1)

plots:-contourplot(M, x = -100 .. 100, y = -100 .. 100, title = contour, grid = [100, 100], colorbar = false)

 
 

NULL

Download control-trajectory.mw

Hi,

just a quick design question regarding my animation. The color "AliceBlue" disappears from my background... Could it be a background option issue?

Q_AlceBlue_background.mw

THis IC for Abel ode is not valid and should result in no solution. But instead of returning NULL, dsolve throws internal error called Error, (in dsolve) invalid limiting point

restart;

interface(version);

`Standard Worksheet Interface, Maple 2024.2, Windows 10, October 29 2024 Build ID 1872373`

Physics:-Version();

`The "Physics Updates" version in the MapleCloud is 1844 and is the same as the version installed in this computer, created 2025, January 25, 22:5 hours Pacific Time.`

ode:=diff(y(x),x)-x^a*y(x)^3+3*y(x)^2-x^(-a)*y(x)-x^(-2*a)+a*x^(-a-1) = 0;

diff(y(x), x)-x^a*y(x)^3+3*y(x)^2-x^(-a)*y(x)-x^(-2*a)+a*x^(-a-1) = 0

DEtools:-odeadvisor(ode);
sol:=dsolve([ode,y(1)=1])

[_Abel]

Error, (in dsolve) invalid limiting point

tracelast;

 dsolve called with arguments: [diff(y(x), x)-x^a*y(x)^3+3*y(x)^2-x^(-a)*y(x)-x^(-2*a)+a*x^(-a-1) = 0, y(1) = 1], arbitraryconstants = subscripted, atomizenames = true, build = false, numeric = false, type = none
 #(dsolve,80): error

 \`dsolve/IC\` called with arguments: [diff(y(x), x)-x^a*y(x)^3+3*y(x)^2-x^(-a)*y(x)-x^(-2*a)+a*x^(-a-1) = 0, y(1) = 1], {y(x)}, skipimplicit = false, skippparticularsolforlinearODEs = true, solution = {}, usesolutions = particular and general
 #(\`dsolve/IC\`,64): draft := procname(_passed,':-usesolutions = "general"');

 \`dsolve/IC\` called with arguments: [diff(y(x), x)-x^a*y(x)^3+3*y(x)^2-x^(-a)*y(x)-x^(-2*a)+a*x^(-a-1) = 0, y(1) = 1], {y(x)}, skipimplicit = false, skippparticularsolforlinearODEs = true, solution = {}, usesolutions = general
 #(\`dsolve/IC\`,277): zz := map(op,{\`dsolve/IC/_C\`({ANS[i]},funcs,x,ics)});

 \`dsolve/IC/_C\` called with arguments: {y(x) = -exp(2*x^(-a+1)/(a-1))/(_C[1]-2*2^(2*(a+1)/(a-1))*(1/(-a+1))^((a+1)/(a-1))*(2^(-(5*a-3)/(a-1))*(1/(-a+1))^(-(a+1)/(a-1))*x^(2*a)*(-a+1)^2*(x^(-a+1)/(-a+1))^(1/(a-1))*(-4*x^(-a+1)*a^2/(-a+1)+8*a*x^(-a+1)/(-a+1)-4*x^(-a+1)/(-a+1)+2*a-2)*WhittakerM(-(a+1)/(a-1)+1/(a-1), -1/(a-1)+1/2, 4*x^(-a+1)/(-a+1))*exp(-2*x^(-a+1)/(-a+1))/((a+1)*(-3+a))-2^(-(3*a-1)/(a-1))*(1/(-a+1))^(-(a+1)/(a-1))*x^(2*a)*WhittakerM(-(a+1)/(a-1)+1/(a-1)+1, -1/(a-1)+1/2, 4*x^(-a+1)/(-a+1))*(-a+1)^2*(x^(-a+1)/(-a+1))^(1/(a-1))*exp(-2*x^(-a+1)/(-a+1))/((a+1)*(-3+a)))/(-a+1))^(1/2)+x^(-a)}, {y(x)}, x, [y(1) = 1]
 #(\`dsolve/IC/_C\`,1): ans := \`dsolve/IC/_C/do\`(solns,depvars,t,inits,'evaluated_ans', "default",':-giveup = giveup');

 \`dsolve/IC/_C/do\` called with arguments: {y(x) = -exp(2*x^(-a+1)/(a-1))/(_C[1]-2*2^(2*(a+1)/(a-1))*(1/(-a+1))^((a+1)/(a-1))*(2^(-(5*a-3)/(a-1))*(1/(-a+1))^(-(a+1)/(a-1))*x^(2*a)*(-a+1)^2*(x^(-a+1)/(-a+1))^(1/(a-1))*(-4*x^(-a+1)*a^2/(-a+1)+8*a*x^(-a+1)/(-a+1)-4*x^(-a+1)/(-a+1)+2*a-2)*WhittakerM(-(a+1)/(a-1)+1/(a-1), -1/(a-1)+1/2, 4*x^(-a+1)/(-a+1))*exp(-2*x^(-a+1)/(-a+1))/((a+1)*(-3+a))-2^(-(3*a-1)/(a-1))*(1/(-a+1))^(-(a+1)/(a-1))*x^(2*a)*WhittakerM(-(a+1)/(a-1)+1/(a-1)+1, -1/(a-1)+1/2, 4*x^(-a+1)/(-a+1))*(-a+1)^2*(x^(-a+1)/(-a+1))^(1/(a-1))*exp(-2*x^(-a+1)/(-a+1))/((a+1)*(-3+a)))/(-a+1))^(1/2)+x^(-a)}, {y(x)}, x, [y(1) = 1], evaluated_ans, default, giveup = giveup, usecansolve = false
 #(\`dsolve/IC/_C/do\`,133): Solns := map((u, S) -> map(limit,S,op(u)),csol,Solns);

 limit called with arguments: y(x) = -exp(2*x^(-a+1)/(a-1))/(_C[1]-2*2^(2*(a+1)/(a-1))*(1/(-a+1))^((a+1)/(a-1))*(2^(-(5*a-3)/(a-1))*(1/(-a+1))^(-(a+1)/(a-1))*x^(2*a)*(-a+1)^2*(x^(-a+1)/(-a+1))^(1/(a-1))*(-4*x^(-a+1)*a^2/(-a+1)+8*a*x^(-a+1)/(-a+1)-4*x^(-a+1)/(-a+1)+2*a-2)*WhittakerM(-(a+1)/(a-1)+1/(a-1), -1/(a-1)+1/2, 4*x^(-a+1)/(-a+1))*exp(-2*x^(-a+1)/(-a+1))/((a+1)*(-3+a))-2^(-(3*a-1)/(a-1))*(1/(-a+1))^(-(a+1)/(a-1))*x^(2*a)*WhittakerM(-(a+1)/(a-1)+1/(a-1)+1, -1/(a-1)+1/2, 4*x^(-a+1)/(-a+1))*(-a+1)^2*(x^(-a+1)/(-a+1))^(1/(a-1))*exp(-2*x^(-a+1)/(-a+1))/((a+1)*(-3+a)))/(-a+1))^(1/2)+x^(-a), _C[1] = exp((4*I)*Im(1/(a-1)))*infinity, parametric = false
 #(limit,2): return map(thisproc,_passed)

 limit called with arguments: y(x), _C[1] = exp((4*I)*Im(1/(a-1)))*infinity, parametric = false
 #(limit,33): error "invalid limiting point"

Error, (in dsolve) invalid limiting point

 locals defined as: ddir = ddir, dexpr = y(x), fexpr = fexpr, r = r, x = _C[1], fL = fL, L = exp((4*I)*Im(1/(a-1)))*infinity, efloat = efloat, lfloat = lfloat, ind_dexpr = ind_dexpr, ind_L = ind_L, lexpr = lexpr, t = t, limr = limr, liml = liml, pt = (_C[1] = exp((4*I)*Im(1/(a-1)))*infinity), inertfunctions = {}, limitX = limitX, parameters = parameters, Y = Y, limc = limc, cexpr = cexpr, texpr = texpr, bexpr = bexpr, limt = limt, limb = limb, param = param, c = c, N = N, Z = Z, P = P, o = o, e = e, uneval = uneval, i = i, A = A, cond = cond, ll = ll, rr = rr

 


 

Download internal_error_instead_of_no_solution.mw

Is there an equivalent of currentdir() which instead of returning current working directory, returns the directory of the file being read. So assume I have an ".mm" or ".mpl" file saved in some location and there is another file with a location fixed relative to this file, but not fixed in absolute location on the computer and not fixed relative with current working directory. One natural thing is to have a line in the first file that takes its current location (not current working location of the user!) and then use the fixed relative path info, and then gives the location of the second file to the user. Using currendir won't help here because current working directory is not necessarily the same as the location of the file you are reading, the first file. One may say the user is reading the first file so he knows already its location, right? Well, if the user is also the writer of the file, sure, not a problem, he can manually edit the lines of the file and put that location inside the file instead of using currentdir etc. However, if the user is not the writer and also does not know how to edit or whatever else reason, then the file should be able to inform Maple of its own location, so that's why something like currentdir() but not for the working directory, instead for currently being read file's directory is helpful. I checked FileTools package quickly and couldn't notice anything like what I want. Anyone have any clue on name of such command if exists or any other trick that does what I want (except expecting the user to do something ^_^ so all from the writer's side please ^_^).

Hi, I want to generate a matrix of variables, say, something like, 

n:=4:

Matrix(n, n, [[a_11, a_12, a_13, a_14], [a_12, a_22, a_23, a_24], [a_13, a_23, a_33, a_34], [a_14, a_24, a_34, a_44]]) :

How can I do it automatically for arbitrary values of n?

is(Im(x)*x = 0);
                              true

 

Surely, Im(i)*i != 0?

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