I am trying to solve an equation with respect to the variable w. However, although there seems to be a solution (see plot indicating a root), Maple produces the wron solution (0, when P = 1/2 and d = 1/10):

Download MaplePrimes_03072018.mw

This pde used to be solved in 2018 as far as I know. Now it gives a strange new error

restart;
interface(showassumed=0);
pde :=  diff(u(x,t),t)+k*diff(u(x,t),x$2)+sin(2*Pi*x/L);
ic  :=  u(x,0)=f(x);
bc  :=  D[1](u)(0,t)=0, D[1](u)(L,t)=0;
sol :=  pdsolve({pde,ic,bc},u(x,t)) assuming L>0,t>0,k>0;

Error, (in assuming) when calling 'dsolve'. Received: 'found differentiated functions with same name but depending on different arguments in the given DE system: {F0_0(L), F0_0(x)}'

I am using  Physics:-Version();     MapleCloud version: 72

Do others get this erorr? Why does it show up now when it worked OK before?

update

Iam running on Linux. Here is screen shot

Hello, can someone help me please?

I have to find the minimum (x,y) over the domain [0;2Pi] of the following function

f(x,y):=1+8 cos(1/2 x-1/2 y) cos(1/2 x) cos(1/2 y) which i plotted to have an idea where its minimum is located.

plot3d(f(x,y),x=0..2Pi,y=0..2Pi)

I tried to use the command  ' minimize(f(x,y)) '

Thank you in advance,

best regards.

 Ps: the function normaly attains its minimum at (2Pi/3,-2Pi/3) and (-2Pi/3,2Pi/3).

Hello dear users!

Hope you would be fine. I want to fine the roots of the following cubic equation

u^3+u*d[1]+d[0];

when the discriment is zero, positive and negative. I am waiting your positive response. Thanks

@acer @Carl Love @Kitonum @Preben Alsholm

I want to calculate and reproduce this question  in Maple.

with(Optimization):

f := (x, y) -> op(1, NLPSolve(sin(a*x*y), a = 1 .. 5));

int(`if`(f(x, y) > 0, 1, 0), [x = 0 .. 1, y = 0 .. 1], numeric);

# 0 

,but I FAIL.

It should give me: 0.922105

Thanks.

I have three columns of data (real numbers) in Excel that have about one thousand rows and I wish to plot their relationships in Maple. The source data simply comprises three columns of numbers and so, are not ordered in triples, [x,y,z]. Does anyone know of a simple routine available that allows me to import the raw data and output a 3-D wire / solid plot in Maple?

Thank you! 

a1:=odeplot(p,[t,x(t)],0..5,color=black,thickness=2):

a2:=plot((2/125)*t^3-(3/25)*t^2+t+1,t=0..5,color=red,style=point,thickness=4):
display(a1,a2,labels=[x1,x2]);
Error, (in plots:-display) expecting plot structure but received: a1
 

I have an explicit mathematical expresssion in the form

I wonder if it is possible to use the collect function on the vector  and write the resulting expression as the dot product

Basically, I am interested in obtaining the vector ^T as a Maple variable in closed-form.

Thank you in advance for your help.

Marco

I'm referancing the maple help page: https://www.maplesoft.com/support/help/maple/view.aspx?path=Groebner in my thesis, but I am not sure what fields to include, and what to put in them- particularly for the year.

I'm a newbie.I am trying to solve a differential equation symbolically.But I'm having  a\some problem.

First 3 lines works fine....but 4th line gives no output...

Secondly How I'm supposed to simplify the output of 3rd line

1.>ode := P*(diff(y(x), x, x))+diff( K(x)*(diff(y(x), x, x)), x, x ) = 0

2.>ics := y(0) = 0, y(L) = 0, ((D@@2)(y))(0) = 0, ((D@@2)(y))(L) = 0

3.>dsolve(ode, y(x))

3rd lines output--y(x) = _C2*x+_C1+Int(DESol({diff(_Y(x), x, x)+2*(diff(K(x), x))*(diff(_Y(x), x))/K(x)+(P+diff(K(x), x, x))*_Y(x)/K(x)}, {_Y(x)}), [x, x]) 

4.>dsolve({ics,ode},y(x))

5.>

4th lines gives no output.After hitting "Enter",I get a new line in my Worksheet(line 5).Why..can anyone explain please?

I want to match   a*x^b only if "a" and "b" are both not the symbol "y"

Therefore 5*x^y should fail to match, but this below matches.

restart;
expr:=5*x^y;
if patmatch(expr,conditional(a::anything*x^(b::anything),(a<>y and b<>y)),'la') then
   print("it matched, why??");
   map(assign,la):
   print("a = ",a, " b=",b);
fi;

it gives

                      "it matched, why??"
                      "a = ", 5, " b=", y

What did I do wrong? is my conditional wrong above?

I was working through some example problems and came across this statement.  Actually comparing Sympy results to Maple. (I prefer Maple).

"Calculate the volume integral of f(...) over the sphere of radius r"

I can solve the problem, but, got hung up on the exact meaning of the problem statement.

Tom Dean

restart
with(VectorCalculus):
with(LinearAlgebra):

## http://www.acme.byu.edu/wp-content/uploads/2017/08/Sympy.pdf
## Problem 7

f := proc(x, y, z)
    (x^2 + y^2 + z^2)^2
end proc;

(M, d) := Jacobian([rho*sin(phi)*cos(theta),
                    rho*sin(phi)*sin(theta),
                    rho*cos(phi)],
                   [rho, phi, theta],
                   'determinant' );
abs(d);
simplify(%);

eqn := f(rho*sin(phi)*cos(theta), rho*sin(phi)*sin(theta), rho*cos(phi));
eqn := eqn * abs(simplify(d));

soln := int(eqn,[rho=0..r,theta=0..2*Pi,phi=0..Pi]);
subs(r=3, soln);

How I can convert Root Of to conventional form?

Thanks

root_of.mw
 

Download root_of.mw

update_standings_ELO_draw.mw

This latest question involves ELO, which is used to rate chess players (and other sports).

The difference between the previous (win-loss) system and ELO is the allowance for a third option, a draw. Carl coded the previous rating system, and I have tried to alter it.

See code for ELO procedure.

Adding a D to the third field, gets the result I want.

ELO(Record(rating= 2400),Record(rating= 2000),D)

Adding anything other than D to the third field means the first player defeats the second.

My preference would be to leave nothing in this third field to signify this (but I don't know if this is possible). 

The main problem is getting the bulk processing to work (for a series of matches...)

See Update procedure.

I have this flawed notation:

Games:= [[Tom_C, David_J, D],[David_J, Tom_C]]: #Tom_C drew David_J then David_J defeats Tom_C.

Hope someone can help.

I am a newbie. I m having some problems in solving generalised eigenvalue problem for symbolic matrices. Help me to discover the problems with this code.

Here is my code:-

>with(LinearAlgebra):

> M := Matrix(2, 2, [4*(I*E/L^3), 6*(I*E/L^3), 6*(I*E/L^3), 24*(I*E/L^3)])

> G :=Matrix(2,2,[2/(15)(-1/(L)),1/(10)(-1/(L)),1/(10)(-1/(L)),12/(5)(-1/(L))])

> Eigenvalues(M, G, output = 'Vector[row]')

Error:-

Error, (in LinearAlgebra:-Eigenvalues) invalid input: LinearAlgebra:-Eigenvalues expects its 2nd argument, C, to be of type Matrix(square) but received G