Maple 2016 Questions and Posts

These are Posts and Questions associated with the product, Maple 2016

I need yours hepl.  I work with the physics paсkage and I set:

with(Physics)

Setup(mathematicalnotation = true)

 Coordinates(X)

Setup(Dgammarepresentation = standard)

Setup(spaceindices = uppercaselatin)

Define(M, aa, mu, mu5, Pi, eta)

M_[mu, mu5] := Dgamma[mu]*d_[mu]+M+Psigma[A]*aa[A]-mu*Dgamma[0]-mu5*Dgamma[0]*Dgamma[5]+i*Dgamma[5]*Psigma[B]*Pi[B]+i*Dgamma[5]*eta

And next:

Dagger(M_[mu, mu5])

How is Maple explained that  

Dagger(d_[mu])=d_[mu]

conjugate(M)=M

conjugate(aa[A])=aa[A]

conjugate(i)=i

and so on?

Dear Friends, I work with physics paсkage. I have a quation. I don't understend how one works with metrics. For example, let:

Nice!
Very good!

1) It doesn't work. Why? (I want exactly gamma_[A,B], rather than g_[A,B], because as i guess gamma_[A,B] has a signature [1,1,1] but g_[A,B] has a signature [-1,-1,-1])

 2) And how may I see what is matrices g_[A, B], gamma_[A, B] explicitly? That is I know how to see what is g_[mu, nu], for this one needs write "g_[];".  But how may I see g_[A, B] and gamma_[A, B] in explicitly forms?

3) Why command Trace(g_[mu, nu]))  does not work?"

Simple issue. I think it is a bug, but if not, it tends to cause logic problems with new users of Maple.

with(plots):
z := A*x*y:
A:=1.0:
plot3d(z, x=0..1, y=0..1); # works as expected
contourplot(z, x=0..1, y=0..1); # works
fieldplot(z, x=0..1, y=0..1); 
    --> Error, (in plots/fieldplo) invaled 1st argument (the function) 1.0*x*y

Is there something special about what the fieldplot expects for the function? I don't see it in the help. Or is this a bug?  

Yes, there is a work around, define all constants first

A:=1.0:   z := A*x*y: fieldplot(z, x=0..1, y=0..1); 

But I fail to understand why my example should fail. (Note, I have seen this situation for every version, so it is not new.)

Dear Friends, I work with physics paсkage. And I don't know how to simplify the next expression: Dgamma[mu]*a[mu]*Dgamma[nu]*a[nu]

(I want to obtain  the well-known result a2 )

The command "Simplify" doesn't work in this case.

There seems to be a bug in determining the folowing integral analytically:

integrate(-(3/2*(exp(-(1/4)*x)*x-sqrt(Pi)*erf((1/2)*sqrt(x))*sqrt(x)))/(sqrt(x)*sqrt(Pi)*erf((1/2)*sqrt(x))), x = 0..1)

Maple gives as a result

3/2

However, numerically integrating it

integrate(-(3/2*(exp(-(1/4)*x)*x-sqrt(Pi)*erf((1/2)*sqrt(x))*sqrt(x)))/(sqrt(x)*sqrt(Pi)*erf((1/2)*sqrt(x))), x=0..1,numeric)

gives

0.1195461293

In fact, integrating it from a to b,

integrate(-(3/2*(exp(-(1/4)*x)*x-sqrt(Pi)*erf((1/2)*sqrt(x))*sqrt(x)))/(sqrt(x)*sqrt(Pi)*erf((1/2)*sqrt(x))), x=a..b)

gives

-3/2 a + 3/2 b

suggesting that Maple thinks the integrand is just 3/2. If one plots it, then it becomes obvious that this is not the case.

I cant understend how to use new Maple workbook, and i cant load it on a site so i will use screenshoots to explain. I whant to add my costume functions to code attachments and exceuted them in multitipe workshellds, but i dont know how to excecude them from ther + i cant understend how varibles sistem work. For excemple i go main document ex1, in it i save z as global varible for all worksheed, when i excecute it works alright in other workdoxument c2 but when i change it in main document it didnt change in others, but in saved varibles in ex1 saved new value of z , and in all others z is left same as it was. In such whay i can save function f2 wich is declorated in workdocument c2 as varible, it will exceute in main ex1 but any changes of f2 in c2 wudent be applied in ex2, if i declorated and excecude f1 in c1 code attachment it dont even generate in varibles tables + i dont see any whay to excecute it from ex1, so here the qestion how to excecute functions saved in code attachments in other book's wordsheets and how make saved varibles usable in all book?


 

with(Statistics):````

X := Statistics:-RandomVariable(Normal(0, 1)):

PDF(sin(X), t)

piecewise(t <= -1, 0, t < 1, 2^(1/2)*exp(-(1/2)*arcsin(t)^2)/(Pi^(1/2)*(-t^2+1)^(1/2)), 1 <= t, 0)

(1)

int(%, t = -1 .. 1)

2*erf((1/4)*Pi*2^(1/2))

(2)

evalf(%)

1.767540069

(3)

``


There were recently submitted a dozen Maple bugs by me and others. Maplesoft have brought no responses. They keep strategic silence. True merit is not afraid of criticism.

Download Bug_in_Statistics_PDF.mw

Let us consider 

restart; J := int(cos(a*x)^2/(x^2-1), x = -infinity .. infinity, CPV);
-(1/4)*Pi*sin(2*a)*csgn(I*a)-(1/4)*Pi*sin(2*a)*csgn(I/a)

This result is not true for a=I:

eval(J, a = I);
                               0

In this case the integral under consideration diverges because of 

cos(I*x)^2;
                                
                            cosh(x) ^2

 

Let us consider 

maximize(int(exp(-x^4), x = k .. 3*k), location);

Error, (in maximize) invalid input: iscont expects its 1st argument, f, to be of type algebraic, but received x = k .. 3*k
whereas the expected output is 

[(2*((1/40)*GAMMA(1/4, (1/80)*ln(3))*5^(1/4)*ln(3)^(3/4)-(1/40)*GAMMA(1/4, (81/80)*ln(3))*5^(1/4)*ln(3)^(3/4)))*5^(3/4)*(1/ln(3))^(3/4), [k = (1/10)*10^(3/4)*ln(3)^(1/4)]]

as Mma 11 produces. The following 

RealDomain:-solve(diff(int(exp(-x^4), x = k .. 3*k), k));
  -(1/10)*5^(3/4)*ln(3)^(1/4), (1/10)*5^(3/4)*ln(3)^(1/4)

is not a workaround because of 

int(exp(-x^4), x = (1/10)*5^(3/4)*ln(3)^(1/4) .. (3/10)*5^(3/4)*ln(3)^(1/4));
  FAIL

 

Hi, I was wondering, as stated in the title, if it is possible to plot/draw a triangle knowing only the sides and angles, and not the coordinates for each point making up its corners. If not, what would be the easiest way, to calculate the coordinates using the sides and angles (assuming I know the value for each side and corner) and then plot/draw it?

I'm rather green when it comes to using Maple, so if you could explain it in a simple way that would be appreciated. 

I try to solve numerically a boundary VP for ODE with different order of discontinuity of right part.

Say, the following BVP is given:

y''(x)+y'(x)+y(x)=F(x)

y(0)=1, y(2)=1

Let's use piecewise right part

F  := piecewise(x<=1, -x, x>1, 2*x+(x-1)^2)

plot(piecewise(x<=1, -x, x>1, 2*x+(x-1)^2), x=0..2,thickness=5)

The function

piecewise(x<=1, 1-x, x>1, (x-1)^2)

plot(piecewise(x<=1, 1-x, x>1, (x-1)^2), x=0..2, color=blue,thickness=5)

as obviuos, satisfies the BVP exclung the point x=1, where its 1st and 2nd derivatives are discontinuos.

Numerical solution

N0:=6:
As:=dsolve([diff(y(x), x$2)+diff(y(x), x)+y(x)=F,  y(0)=1, y(2)=1], y(x), type=numeric, output = Array([seq(2.0*k/N0, k=0..N0)]), 'maxmesh'=500, 'abserr'=1e-3):

provides the solution essentially different to exact one described above:

But if to use the right part

F := piecewise(x<=1, x^2+x+2, x>1, -x^2+x)

plot(piecewise(x<=1, x^2+x+2, x>1, -x^2+x), x=0..2, color=blue,thickness=5)

for which the function

piecewise(x<=1, 1-x+x^2, x>1, -1+3*x-x^2)

plot(piecewise(x<=1, 1-x+x^2, x>1, -1+3*x-x^2), x=0..2, thickness=5)

satisfies the BVP excluding x=1, where this function has discontinuity of 2nd derivative only, the corresponding numerical solution is very similar to this exact solution:

This reason of the difference between these two cases is clear. In the first case both 1st and 2nd derivatives are discontiuos, while in the second one -- 1st derivative is contiuos.

I wonder, if there are numerical methods, implemeted in Maple, for numerical solution of the first type BVP with non-smooth right part?

Let us consider 

MultiSeries:-series(Psi((2*x+1)/(2*x))-Psi((x+1)/(2*x)), x = 0);

x-(1/2)*x^2+(1/4)*x^4-(1/2)*x^6 +O(x^7)

The above result contradicts 

MultiSeries:-limit(diff(Psi((2*x+1)/(2*x))-Psi((x+1)/(2*x)), x), x = 0);
                           undefined
MultiSeries:-limit((Psi((2*x+1)/(2*x))-Psi((x+1)/(2*x)))/x, x = 0, right);
                               1
MultiSeries:-limit((Psi((2*x+1)/(2*x))-Psi((x+1)/(2*x)))/x, x = 0, left);
                           undefined
plot((Psi((2*x+1)/(2*x))-Psi((x+1)/(2*x)))/x, x = -0.1e-1 .. 0.1e-2, discont, y = -5 .. 5);

How can I get maple2016 to simplify sqrt(3579757) to 151*sqrt(157) ?

HI

please help me for dsolve this nonlinear differential equations

thanls...

HAB.mw
 

restart; Digite := 100; Phi0 := 5; A := b*h; g13 := 31/250000000; g1 := 113/500000; f13 := 1/1000000000; c1 := 226000000000000; b := 10*10^(-9); J := (1/12)*b*h^3; h := 15*10^(-9); L := 100*10^(-9); E1 := (339/10000000000000000000000)*(diff(u(x), x, x, x, x))+(1017/10000000000000000000000)*(diff(w(x), x, x))*(diff(w(x), x, x, x))+(339/10000000000000000000000)*(diff(w(x), x, x, x, x))*(diff(w(x), x))-(339/10000)*(diff(u(x), x, x))-(339/10000)*(diff(w(x), x))*(diff(w(x), x, x)) = 0

E2 := -(1017/1600000000000000000000000000000000000000)*(diff(w(x), x, x, x, x, x, x))+(1589109/2500000000000000000000000)*(diff(w(x), x, x, x, x))-(339/10000*(diff(u(x), x, x)+(diff(w(x), x))*(diff(w(x), x, x))))*(diff(w(x), x))-(diff(w(x), x, x))*((339/10000)*(diff(u(x), x))+(339/20000)*(diff(w(x), x))^2+0.5824000000e-4)+(339/10000000000000000000000)*(diff(w(x), x, x))*(diff(u(x), x, x, x)+(diff(w(x), x, x))^2+(diff(w(x), x, x, x))*(diff(w(x), x)))+(339/10000000000000000000000)*(diff(w(x), x))*(diff(u(x), x, x, x, x)+3*(diff(w(x), x, x))*(diff(w(x), x, x, x))+(diff(w(x), x, x, x, x))*(diff(w(x), x)))-2 = 0:
 

E3 := -5.385803274*10^(-17)*(diff(Phi(x), x, x))+2.659881780*Phi(x)-5.125107476*10^(-20)*(diff(psi(x), x, x))+1.146681319*psi(x)+3.300000000*10^(-8)*(diff(w(x), x, x)) = 0:

E4 := -5.125107476*10^(-20)*(diff(Phi(x), x, x))+1.146681319*Phi(x)+(891/100000000000000)*(diff(psi(x), x, x))/Pi+34976.39822*psi(x)+0.4351500000e-5*(diff(w(x), x, x)) = 0:

dsys3 := {EQ1, EQ2, EQ3, EQ4, c1*J*((D@@2)(w))(0)+A*g13*((D@@2)(w))(0)-2*b*f13*Phi0-g1*J*((D@@4)(w))(0)+g1*A*(((D@@2)(u))(0)+((D@@1)(w))(0)*((D@@2)(w))(0))*((D@@1)(w))(0) = 0, c1*J*((D@@2)(w))(L)+A*g13*((D@@2)(w))(L)-2*b*f13*Phi0-g1*J*((D@@4)(w))(L)+g1*A*(((D@@2)(u))(L)+((D@@1)(w))(L)*((D@@2)(w))(L))*((D@@1)(w))(L) = 0, Phi(0) = 0, Phi(L) = 0, psi(0) = 0, psi(L) = 0, u(0) = 0, u(L) = 0, w(0) = 0, w(L) = 0, (D(u))(0) = 0, (D(u))(L) = 0, ((D@@2)(w))(0) = 0, ((D@@2)(w))(L) = 0}; dsolve(dsys3, numeric, initmesh = 3024, abserr = 0.1e-4)

Error, (in dsolve/numeric/process_input) system must be entered as a set/list of expressions/equations

 

``


 

Download HAB.mw

 

restart; with(Statistics):
X := RandomVariable(Normal(0, 1)): Y := RandomVariable(Uniform(-2, 2)):
Probability(X*Y < 0);

crashes my comp in approximately 600 s. Mma produces 1/2 on my comp in 0.078125 s.

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