f := x -> 2*x/(x + 3)

p1 := plot(f(x), x = 0 .. 100);

p2 := with(plots);
inequal(58 < x, x = 0 .. 100, y = 0 .. 2);

display([p1, p2]);

Error, (in plots:-display) expecting plot structures but received:

How do i combine to p1 and p2 in the same graph. They print well individually..  Its maple 2021

Hello

I could not come up with a better title, so I apologize for that.  Let me explain what I am trying to implement using an example. 

Consider the following list of monomials (a 3D model,  4 monomials altogether):

model := [x^2*y*alpha[1, 11], x*z^2*alpha[2, 15], y^2*z*alpha[3, 17] + y*z*alpha[3, 8]]

The idea is to generate the set of all models by adding a non-repetitive monomial from the following list to model.

[alpha[i, 0], alpha[i, 1]*x, alpha[i, 2]*y, alpha[i, 3]*z, alpha[i, 4]*x^2, alpha[i, 5]*y*x, alpha[i, 6]*z*x, alpha[i, 7]*y^2, alpha[i, 8]*z*y, alpha[i, 9]*z^2, alpha[i, 10]*x^3, alpha[i, 11]*y*x^2, alpha[i, 12]*z*x^2, alpha[i, 13]*y^2*x, alpha[i, 14]*z*y*x, alpha[i, 15]*z^2*x, alpha[i, 16]*y^3, alpha[i, 17]*z*y^2, alpha[i, 18]*z^2*y, alpha[i, 19]*z^3]

where i indicates the coordinate where the monomial will be included.  Example: if alpha[i, 2]*y is to be added to the second coordinate of model it goes as alpha[2,2]*y. Note that alpha[i, 15]*z^2*x cannot be added to coordinate 2 since it is already there.  

The result will be a list of 56 models with 5 monomials. 

How can I do that efficiently?  

Many thanks

Ed.

PS. I have implemented something similar to the problem above, but I have used too many 'for' loops. 

I have a result:

u1 = RootOf(4*_Z^2 + (4*RootOf(60*_Z^3 - 60*_Z^2 + 15*_Z - 1) - 4)*_Z + 4*RootOf(60*_Z^3 - 60*_Z^2 + 15*_Z - 1)^2 - 4*RootOf(60*_Z^3 - 60*_Z^2 + 15*_Z - 1) + 1)

I tried: convert(u1,'radical');

but it reported error Error, (in sprintf) too many levels of recursion

how can I convert it to this form?

Thanks!!

Hello! We are using Maple to evaluate numerically expressions with very high precision and we are finding very strange results. After some playing with simple models we have come to conclusion that there might be a bug in Maple 2023. Here is a clean example of what we are experiencing. Plotting the function x*exp(-x) in [0,20]. Clearly the function cannot be negative in that interval! However, if Digits is set to 40 the results may be whatever. Any ideas? Thank you very much. 

Trying to figure out how to save a slice of an array to a repository.

for example: savelib(vmcofs[1],lib) [where lib is my repository location]

I'm getting the error: Error, invalid input: savelib expects its 1st argument, to be of type symbol, but received vmcofs[1]

Quoting it doesn't seem to help.

I need to do this programmatically as I will be incremented the row number in the array and saving partial data at each step.

That is...savelib(vmcofs[1],lib) then savelib(vmcofs[2],lib), etc.

I can save the whole array. Is there a more efficient way of doing this?

Hello everyone!

I'm using Maple 18. The problem is that fsolve does not solve equations, or more precisely, it does not pass the values of sU - from its range, and sV - from its range, to shootNL. As a result, R value:=[]; . I would like to ask for help in solving this problem.

I have attached the Maple source file.

fsolveProblem.mw

I want to plot a graph of sets of o d e for a disease model with varying perimeters please how do I get the plot functions and how should the graphs look like for each parameter I vary

I'm interested in created a group ring, but have no idea how to do it.

In short, a group ring is a free module with the scalars as elements of a ring,R, and the vectors as elements in a group, G. [Wikipedia has a decent description.]

Elements a=r0*g0 and b=r1*g1 have sum a+b=r0*g0+r1*g1 and product a*b=r0*r1*g0*g1

The distributive property is followed.

Suggestions?

Is there a way to remove a unit symbol?  "AddUnit" allows to add additional symbols or change the default symbol, but I don't see any way to remove symbols?

A good example is for the hectare.  Maple 2023 uses "a" as the default symbol for the are, except that the unit symbol "a" does not allow using SI prefixes because the peta- unit prefix then conflicts with the pascal ("Pa").  I can use "AddUnit" to change the default symbol for the are from "a" to "are" but I still cannot enable SI prefixes unless the symbol "a" is removed from the symbol set.  This way hectares ("hare") and petares ("Pare") can be used.

I don't see a way to nondestructively/temporarily delete units either ("RemoveUnit").  Deleting the unit "are" and then recreating it as a new unit with the symbol "are" would solve the same problem.

I just saw that there already exists a separate "hectare" unit with the symbol "ha" which presumably also needs to be removed in order to enable SI prefixes for "are".  This is just one example but a general way to remove units and/or unit symbols should be very helpful.

hi i need help. can someone help me with maple command for this 2 question? i need to do it for my assignment. all i know that i need to use with(vectorcalculus). all command include graph. thanks

In case this error has been corrected in more recent versions, please feel free to delete this question.

In the felp page relative to anames this example is given

restart:
test1 := 1: test2 := 2: test3 := 3.2: testall := 3.2:
select(type,{anames()},suffixed(`test`));
                 {test1, test2, test3, testall}

Note the backward quotes in suffixed(`test`).
This works only if test is not an assigned name itself:

restart:
test := 0: test1 := 1: test2 := 2: test3 := 3.2: testall := 3.2:
select(type,{anames()},suffixed(`test`));
Error, (in type/suffixed) expecting a 1st argument of type {string, symbol, list(symbol, string), set(symbol, string)}

With simple quotes:

select(type,{anames()},suffixed('test'));
              {test, test1, test2, test3, testall}

Hi,

I am exploring the counting functions available in Maple, and I am searching for how to enumerate arrangements with repetition and combinations with repetition ? ThanksCombinatoireTEST.mw

How to handle these errors in plotting the solutions?compare.mw

Currently, the argument is mapped to the HUE coloring scheme (I guess)

plots:-complexplot3d(z, z = -2 - 2*I .. 2 + 2*I, title = -ln(1/c) - ln(c), orientation = [-90, 0, 0])

This makes it difficult to distinguish the sign of the argument close to the positive real axis (just to give an example). To increase contrast I thought about alternatives: Linear ramping from 0 to 2pi from one color to another (similar to phase wrapped images) or a stepped color scheme (in pi/4 increments for example).

I tried color=argument(z/2/Pi) but this did work.

Is there a way to import an MPL file from a URL?

Import("https://www.nicolesharp.net/testbox/test.mpl");

Using the "Import" command on Maple 2023.2 appears to only import the MPL as plaintext and doesn't recognize any of the Maple instructions from the MPL file.

Using the "Get" command with the URL package doesn't do anything useful either.

with(URL) : Get("https://www.nicolesharp.net/testbox/test.mpl");