MaplePrimes Questions

Noticed an issue with Vector and excel.  Not even really excel but I found it through that.  

If I select a row in excel and do a copy paste into Maple it sometimes appears as if it's a list.  ie it shows up as [1,2,3,4]  other times it shows up as [ 1 2 3 4 ] signifying an array (for this example I've saved as the data under the variable a).  Running whattype(a) on the data shows they're both arrays.  Of course it's probably wise to instead load data through Excel into Maple by using the ExcelTools and Import option, however I didn't think there was no reason to use the copy paste option.  It does, to some extent, or maybe, well, it shows a limitation.

In the first instance when it shows up as a list, I thought it might be simple enough just to add other numbers in the list ie/ just tack on ,5,6,7,8 after the 4.  But after pressing enter we get the error

Error, invalid sequence

I don't understand why I couldn't just add to the copied data but maybe it's the formatting of the data that was pasted into maple? 

With the original copied data, I can use with(plots):  listplot(a) no problem however, we want to add data.  ArrayTools will let us Append data to the vector

with(plots):
with(ArrayTools):
Append(a,5,6,7,8)

listplot(a) # will throw another error

                  Error, (in plots:-pointplot) points cannot be converted to floating-point values (this doesn't show in Maple 2019 but does come up in Maple 18)

For Maple 2019 it with responds with a returned array [ 1 2 3 4 5,6,7,8]

Running listplot on that Appended Array.  Maple only recognizes the next 1 added value.

So this means appending values using ArrayTools and Append only allows us to append one value at a time?  Is that a bug?  Are there better ways to append values to vectors?  The only solution for that is to convert to a list and use op to append more values.  But perhaps Maple should have understood the copied values from Excel should have been a list or listlist of values?

 

 

 

Can someone help me with the following question?

 

I would like to plot the function f(x)=a*x*(1-x)+x*ln(x)+(1-x)ln(1-x) in the interval [x1,x2], where x1 and x2 are points that satisfy the following: df/dx(x=x1)=df/dx(x=x2)=0 and f(x1)=f(x2), where a is some parameter that is greater than 0.

I guess I need to use here fsolve, but I am not sure how.

Can you please tell me the exact weighting scheme for LinearFit() and NonlinearFit() when using the weights= option?

Is it wi*(yi_exp-yi_calc)^2 or wi^2*(yi_exp-yi_calc)^2 ?

(wi=weight of point i, yi_exp=value i measured, yi_calc= value i calculated from the model function)

Best regards,

 Anthrazius

Any integer in [129,129+13^2[ 1s written as the sum of squares of separate integers equal to or less than 12.
examples:: 129=10^2+5^2+2^2, 130=11^2+3^2... 132=9^2+5^2+4^2+3^2+1^2...
179=12^2+5^2+3^2+1^2...297=12^2+10^2+7^2+2^2. Thank you.

Hompotopy perturbation method

restart; with(LinearAlgebra);
PDEtools[declare](f(x), prime = x);
PDEtools[declare](g(x), prime = x);
N := 3;
F := sum(p^i*f[i](x), i = 0 .. N);
G := sum(p^i*g[i](x), i = 0 .. N);
FEq := (1-p)*(diff(F, x$3))+p*(diff(F, x$3)-(2*(diff(F, x$1))*(diff(F, x$1))-(5/2*F)*(diff(F, x$2))+M*(diff(F, x$1))) . A);
GEq := (1-p)*(diff(G, x$2))+p*(diff(G, x$2)+(5/2*(1/(1+R)) . Pr)*F*(diff(G, x$1)))*K(L);

M := 1;
A := (((1-W)^2.5*(1-W))*`ρf`+W*`ρt`)/`ρf`;
Pr := 6.2;
K := ((1-W)*`ρf`*Cf+W*`ρt`*Cs)/`ρf`;
L := .5;
`ρf` := 998.3;
`ρt` := 3970;
W := .2;
R := 1.0;
Cs := 765;
Cf := 4182;
coeff(FEq, p, 0);
coeff(GEq, p, 0);
for i from 0 to N do Fequ[i] := coeff(FEq, p, i) = 0 end do;
for i from 0 to N do Gequ[i] := coeff(GEq, p, i) = 0 end do;
Fcond[1][0] := f[0](0) = 0, (D(f[0]))(0) = 1, (D(f[0]))(5) = 0; for j to N do Fcond[1][j] := f[j](0) = 0, (D(f[j]))(0) = 0, (D(f[j]))(5) = 0 end do;
Gcond[0] := g[0](0) = 1, g[0](5) = 0; for j to N do Gcond[j] := g[j](0) = 0, g[j](5) = 0 end do;

for i from 0 to N do dsolve({Fequ[i], Fcond[1][i]}, f[i](x)); f[i](x) := rhs(%) end do;
for i from 0 to N do dsolve({Gcond[i], Gequ[i]}, g[i](x)); g[i](x) := rhs(%) end do;
Fa := simplify(sum(f[n](x), n = 0 .. N)); dFa := diff(Fa, x); subs(x = 2.4, dFa);
Ga := simplify(sum(g[n](x), n = 0 .. N)); dGa := diff(Ga, x); subs(x = 2.4, dGa);
plot(Ga, x = 0 .. 5);
plot(dFa, x = 0 .. 5);

ND sove solution 

Eq1 := diff(F(x), x$3)-(2*(diff(F(x), x$1))*(diff(F(x), x$1))-(5/2*F(x))*(diff(F(x), x$2))+M*(diff(F(x), x$1))) . A = 0;
Eq2 := (diff(G(x), x$2)+(5/2*(1/(1+R)))*Pr*F(x)*(diff(G(x), x$1)))*K(L) = 0;
M := 1;
Pr := 6.2;
A := (((1-W)^2.5*(1-W))*`ρf`+W*`ρt`)/`ρf`;
K := ((1-W)*`ρf`*Cf+W*`ρt`*Cs)/`ρf`;
L := 1;
`ρf` := 998.3;
`ρt` := 3970;
W := .2;
R := 2.0;
Cs := 765;
Cf := 4182;

Cd1 := F(0) = 0, (D(F))(0) = 1, (D(F))(5) = 0;
dsys := {Cd1, Eq1};
dsol := dsolve(dsys, numeric, output = operator);
dsol(.1);
plots[odeplot](dsol, [x, diff(F(x), x$1)], 0 .. 5, color = green);
Cd2 := G(0) = 1, G(5) = 0;
dsys := {Cd1, Cd2, Eq1, Eq2};
dsol := dsolve(dsys, numeric, output = operator);
plots[odeplot](dsol, [x, G(x)], 0 .. 5, color = green)

 

I find some book teach motion planning in topology 

but do it need to formulate the equations for the environments such as a map with obstacle in 2d or 3D?  the environment is quite complex, how can these equations be formulated?

 

Dear all

Using maple I can't obtain an exact solution, my goal for which initial condition can the solution diverge to infinity if maple can not give us a solution.

special_condition_diverge.mw

many thanks

 

I have two functions:

f(x)= (x)^(1/2)

g(x)=(x^2)/8

I want to get each function to rotate the y-axis and build the shape and I want the shaded region to build the 3D shape as it goes around the y-axis.

The domains for all would be 0 to 4.

The url link to what I am looking for it below.

https://en.wikipedia.org/wiki/Solid_of_revolution#/media/File:Rotationskoerper_animation.gif

Thank you in advanced!

Maple_question.mw

Hello everyone .

I asked Maple to compute a definite integral of a function, numerically. Unfortunately it does not give me any values . I briefly explain what I did.

As you can see in the picture first I define a real valued function BW_dilog(x) (with complex domain), where the function dilog  already exists in maple. Then I defined another function, V, (with real domain and codomain ). Now I need the approximate value of the bi integral of V, on a triangle. The Maple file is attached.

I would be grateful if any one could help me.

how do i Import part or all  PDF files into maple 

I believe this was easier in older versions of maple or worked partially.

I initialized a variable name using another variable name and := . I thought that Maple would assign the value, but I soon learned by debug that the address was assigned. This led to temporary problems.

 

Where can I learn the rules that Maple follows for assignment by value or address ?? Do I always have to initialize with a real number, like 0, to be safe ??

Thanks.

Mike Graber

x:=Proc
Local a,
b,

C;
use XML Tools in 
end use;

end proc;

Hello,

I have a problem, please help me to solve it.

I am trying to extract coefficients of some polynomial expressions but I receive Error.

For example:

>with(Physics):

>Setup(mathematicalnotation = true)

>S := a*(x^2)+b*x+c*(1/(x-h)):

>Coefficients(S, x, 1)

>Error, (in Physics:-Coefficients) unable to compute coeff.

**** Note that if instead of the term (1/(x-h)) we have (1/x), then we get the true result. The error occurs only when we have some extra things in the denominator namely "-h".

Regards

How I can pdsolve these equations in toroidal coordinates?

Initial conditions are arbitrary.

Please see attached pdf .

Thanks

Where.pdf

Weston1958

Can old maple version saved .m files in window be readable in maple 2015 Linux version?

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