Maple Questions and Posts

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The program below works fine, but comes up with an error message: wrong number (or type) of parameters in function $.  I'm confused as the Maple 7 Help on 'convert, bytes' the $ symbol is omitted.  The program works fine: it is just a little disconcerting, as this is just the start of a general Wordwheel program.

   The error seems to be related to the textplot command - but why?

# # # # # # # # # # # # # # # # # # # # # # # # # # # #
# Wordwheel program - intended to be general
# # # # # # # # # # # # # # # # # # # # # # # # # # # #
#Number of letters, including the ? sign
#Angle of arc for each letter
# Draw the circle
c:=circle([0,0], R, color=black):
#Draw the lines
i from 0 to nolett-1 do
  lin[i] := line([0,0], [R*cos(i*ang),R*sin(i*ang)], color=black,   linestyle=1):
end do:  #i
#Upper & lower case alphabets
#s_L := convert( [$97..122], 'bytes' ):   #a - z
s_U := convert( [$65..95], 'bytes' ):   #A-Z

plots[display](c,tp1, seq(lin[i], i=0..nolett-1), scaling=constrained, axes=none);

Warning, the name changecoords has been redefined

Warning, the name arrow has been redefined

Error, wrong number (or type) of parameters in function $




Download wordwheel.mws


E := proc (n::posint)
local L, x, y, z, p;
p := n; L := NULL;
assume(x::nonnegint, y::nonnegint, z::nonnegint);
assume(x <= y and y < =z);
for x from 1 to irem(p, 2) do
for y from x to irem(p, 2) do
for z from y to irem(p, 2) do
if x+y+z = p then L := L, [x, y, z] end if
end do
end do
end do;
return L end proc:
This procedure don't work. I would like E(9)={(1,4,4),(2,3,4),(3,3,3)} then E(2019), E(2022). Thank you.

Is this documenation wrong?

It says that calling sequence is 

     FetchRow( statement, column, valuetype  )

But below it only shows 



prepared statement obtained using Prepare command



type of the output data, default is "auto"


With no column anywhere.  And none of examples show column in them.

And when I tried it by adding a column name that I know exist in my sqlite3 database, Maple gave an error that no such parameter allowed.  

Does FetchRow support column name or is the above just a documenation error?

Maple 2019



Hello everyone!

Does anyone know if it is possible define a metric like the metric below?



Thanks in advance!

I have the following equation

how I can change it by using this transform 

to get a new PDE only in u(t,x)

then I need to change u(t,x) by 

u(t,x)=u(y) where y=x-a*t

How I can do that in maple

I would like to understand why the 'solve' command is unable to find any solution to the system of equation { x^2=2, x^3=2*sqrt(2) }  (which obviously has a unique solution x=sqrt(2) ). The syntax that I used is
> solve({x^2 = 2, x^3 = sqrt(2)^3}, [x]);
and the output is the empty list.

I suspect that this is related to the presence of the algebraic number sqrt(2). Does anyone have a better understanding ?

I am using Maple version 2018.0, build ID 1298750.

Thank you.


how can i write the tittle on the plot exampe below pic

inequal({sqrt((1/2)*x) < y and sqrt(Pi/(2*x)) < y and y < sqrt(x) and y < sqrt(Pi/x)}, x = 1 .. 3, y = 0 .. 2);

I discovered incidentally that the command  Matrix(3, 3, `-`) (the number 3 is purely illustrative) returned the same result than the command Matrix(3, 3, (i,j) -> i-j).
In the same way `+` realizes (i,j) -> i+j), `*` realizes (i,j) -> i*j), ...

More surprisingly `.` realizes (i,j) -> i*j while I'm in worksheet mode, with "old" maple input style, and that the command 2.3 does not answer 6 but concatenates 2 and 3.

Is this a known behaviour or an undocumented feature?






I bassically have one problem with an integral of the type:

int(diff(f(s), s), s = l .. s)

and I want to change the integration variable. I've founded the IntegrationTools:-Change command, but it simply does not work.

Change(int(diff(f(s), s), s = l .. s), s = S*l, S)

givin the error:
Error, (in IntegrationTools:-Change) unable to determine new range for S

Any help is deeply appreciated.

I have noticed a few times now with Maple 2019. It looses kernel connection when it is sitting there idly. This time I observed it. Had saved a document after an intensive calculation. The memory used was about 30Gig. shortly after saving the cpu fan was running hard. I checked task manager and cpu was cycling to 100%, it was mserever. Then the memory usage droped to about 6gig and message as shown. During this time Maple screen down in the LH corner displayed "Ready", so it didn't think it was doing anything.

I am encountering problems solving a system of differential equations.

In the attached file, on the first try the boundary conditions are defined in H: = He, resulting in "Error, (in DEtools / convertsys) unable to compute coeff". On the second try, the boundary conditions are defined in H: = He + 0.00000000000000001 and this works.

What is the possible cause of the problem?

Thank you


I am attempting to check solutions to a system of ODEs using odetest. However, odetest only appears to partially substitute the provided solution. Furthermore, it appears to be related to the alphabetical order of the functions.

For instance, here I have two functions, phiL and phiM, that satisfy Laplace's equation and are coupled through the boundary conditions, BCs.

laplace := {-phiL(z) + diff(phiL(z),z$2)=0, -phiM(z) + diff(phiM(z),z$2)=0}:
BCs := {phiL(d1)=0,phiM(-d1)=0,phiL(0)=phiM(0), D(phiL)(0)-D(phiM)(0)=-n}:
sol := {
phiM(z) = n/2/coth(d1)*(cosh(z)+coth(d1)*sinh(z)),
phiL(z) = n/2/coth(d1)*(cosh(z)-coth(d1)*sinh(z))

odetest(sol, laplace union BCs,{phiL(z),phiM(z)});

This returns

{0, 1/2*(2*phiL(0)*coth(d1)-n)/coth(d1), D(phiM)(0)-1/2*n}

Here, phiL(0) and phiM(0) are unevaluated even though the provided solutions are valid there.

Furthermore, while renaming phiL to an alphabetically earlier name (eg, phiJ) causes the corresponding change in the output. However, renaming it to something alphabetically after phiM (eg, phiN) causes the terms in the output to switch. That is, changing phiL to phiN in the above code results in

{0, 1/2*(2*phiM(0)*coth(d1)-n)/coth(d1), D(phiN)(0)+1/2*n}

Therefore, it seems to be related to the way Maple internally stores the list of variables.

Is this a bug? Or is there something I'm missing?


My code below works but I an looking to speed it up to apply to large arrays. I have large integers and I want to store the exponent and first and last few digits.

nelems := 10;  ~ takes about 50mins when n=100,000,000
n := 374894756873546859847556;
A := Array(1 .. 4, 1 .. nelems);
st := time();
for i to nelems do
    A[1, i] := i^10*n;
    A[2, i] := length(A[1, i]) - 1;
    b := convert(A[1, i], string);
    A[3, i] := parse(b[1 .. 3]);
    A[4, i] := parse(b[-3 .. -1]);
end do;
time() - st;
A[1, -2];
A[2, -2];
A[3, -2];
A[4, -2];


I am trying to implement a Squarefree Factorization Algo in Maple. 
For several algorithms (like the one in Victor Shoup- A computational Introduction to Number Theory and Algebra) one is in need of computing the pth root (F_q is the finite field with q=p^k) of a polynomial. I tried stuff like pol^(1/p), root[p](pol), proot(pol,p), but either I get NOROOT as output or just the polynomial with the exponent 1/p, like e.g.


(tau my RootOf for the field extension, F_q with q=3^2)
But that doesnt help me, because I will need a polynomial without any exponent so that i can get the derivate pol'=dpol/dx, and that doenst work if there is any exponent...
cTest := `mod`(root[p](c), p);
cStrich := `mod`(diff(cTest, x), p);
          Error, the modular inverse does not exist

Does anybody know how I can calculate the pth root of a polynomial? (At the moment I am following the Algo that is mentioned on wiki for Squarefree Factorization...)

Or, does anybody know a better Algo for a squarefree Factorization? 

Thanks for any help and any answers!

In dark matter cosmology the following integral in x  does not yet have an analytical solution. I report the integral in

Maple 2018 notation

int(1/sqrt((1+x)^3*a+(1-a)*(1+x)^(3+3*b)), x)

If someone has some smart idea is welcome

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