Hi. It is be good to be with you after 4 years.

I want to ask about Curvefitting for Data. If I have a numerical data and i want to find a function in x and y for these data.

After I've set my infolevel and used the ProjectionPlot command, is there any way to force Maple to display the information using exact values, instead of decimal approximations? See the attached file for the additional information.

Download projection_plot.mw

I am plotting a simple rational function. When the denominator is completely factored, the discont command works as expected. However, if the denominator is expanded, discont fails.

Why does this happen?

This behavior also occurs in Maple 17.

Download discont.mw

To me the following behavior of solve is surprising:

restart;
solve(f(0.5)=7,f(0.5)); #Output NULL
solve(f(1/2)=7,f(1/2)); #Output as expected 7

Debugging solve suggested to me that the following might work
solve(f(0.5)=7,f(1/2));
and indeed it did (outout the float 7.).
This behavior seems to have started in Maple 10. I checked Maple V,R3 and several other old versions including Maple 9.5. All behaved as I would have expected. MapleV,R3 gave the float 7. in the first case, the other the integer 7.
I take this to be a bug and shall file an SCR.
Any comments?

g := (1/8)*x*sin(13/x)+arcsin(5*x^2/(8*x^2+1))

G := unapply(g, x)

H(x) :=G(G(x))

I need to find the value of H'(pi/2). I tried this, but it didn't work;

simplify(eval(diff(H(x), x), x = (1/2)*Pi))

Will it not work for this type of question? 

Thanks :)

f(x) :=(x^(12)-x*sin(x^(11)))/(x^(34))+e^(sqrt(x+4))*ln(abs((cos(x)^(5))-6))

diff(f(x), x$2)

What would I need to type in if I would want to find f^-2(5)? I've tried this;

diff(f(5), x$2)

But it keeps giving me zero... Thanks in advance! :)

Statistics:-Histogram by default choses the vertical axis such that the area under the histogram is 1 (or something like that). In my work, I invariably need to add "frequencyscale=absolute" to get the scale I need. Is there any way to make this the default? Typing this every time gets so old... I have been looking to something analogous to plots:-setoptions but that doesn't seem to exist for Statistics.

M.D.

This is going to sounds so stupid probably, but I'm a newbie with the software and I really am clueless at the moment.

I was asked to define given information as a function, then sub -25 in for x to verify I typed the function correctly. But it's not working.. (I have a screenshot saved to my computer, but apperently I can't post it).

f(x) :=(x^(12)-x*sin(x^(11)))/(x^(34))+e^(sqrt(x+4))*ln(abs((cos^(5)x)-6))

This is my function...how do I check what value f(-25) will give me? When I calculate it (first with evalf, then without) it only showed another function as the answer, rather than the answer..sigh, I'm terrible with this software.

Dear MaplePrime's guys,

I would like that the font style of  all (new) worksheets I open are with 'style" "CMaple input" " Courier 20 "..

How could I modify the setting please? Any hint is more than welcome.

I am using Maple 16 (on a MacBook pro).

Thank for your attention,

J.-J. 

I have seen no posting on the following issue: on a high density monitor, example QHD+, where the resolution is 3200x1800, the titlebar, the palettes and the graphs are so small that they are essentially invisible. In addition, the symbols in the palettes overextend the edge of the palette. I see this with both Dell computers and Apple computers that run Maple under Windows. Is true with other computers? Is Maplesoft aware of this issue? I'm assuming it has something to do with the Java graphics library. Is there a solution?

I have an expression like this:
B0:=(phi(x))^2:
B1:=diff(phi(x),x):
B2:=diff(phi(x),x,x):
B3:=B2^2:
B4:=(phi(x))^2:
B5:=B1^2:

C0:=(psi(x))^2:
C1:=diff(psi(x),x):
C2:=:C1^2:
C3:=

D0:=(eta(x))^2:

F1:=phi(x)*psi(x):
F2:=phi(x)*eta(x):
F3:=psi(x)*eta(x):

g1:=B1*C1:
g2:=B2*phi(x):
g3:=B2*psi(x):
g4:=B2*eta(x):

T:=A0011*B0+A0022*C0+A0033*D0+A0012*F1+A0013*F2+A0023*F3+A1111*B5+A1122*C2+A1112*g1+A2011*g2+A2012*g3+A2013*g4+A2211*B5:

A0011 and A0022 and etc are constants and coefficients.

Now I want to extract some constants like A1112 or A2013 from T. Please write out an useful code for extract these coefficients!

Thanks

SmithChart.mw
 If I want to plot Smith Chart ,how do I mark a circle of arbitrary values?

then,How do I avoid the polar line to cover other  circle line?

Any body can give me some ideas or better ways to plot Smith Chart?

Thanks.

Download SmithChart.mwSmithChart.mw

Dear Maple enthusiasts,

I am unable to find a working method to solve a system of 8 equations, of which 4 are differential equations. The system contains 8 unknown variables and the goal is to find an expression for each of these variables as a function of the time t. I have attached the code of my project at the bottom of this message.

I have tried the following:

1. Using solve/dsolve to solve all 8 equations at once. This results in Maple eating up all of my memory and never finishing its calculations.
2. First using solve to solve the 4 non-differential equations so that I get 4 out of 8 variables as a function of the 4 remaining variables. This results in an expression containing RootOf() for each of the 4 veriables I'm solving for, which prevents me from using these expressions in the 4 remaining differential equations.
3. First using dsolve to solve the differential equations, which gives once again an expression for 4 variables as a function of the 4 remaining variables. I then use solve to solve the 4 remaining equations with the new found expressions. This results in an extremely long solution for each of the variables.

The code below contains the 3rd option I tried.

Any help or suggestions would be greatly appreciated. I have been scratching my head so much that I'm getting bald and whatever I search for on google or in the Maple help, I can't find a good reference to a system of differential equations together with other equations.

Download Park_-_mixed_control_model.mw

Hello all of you,

I'm new here and I have a problem.

For homework I have to write a Maple package for the usage of dual quaternions. This is not a problem.

For example two functions of the package:

MyQuaternions := module()

  export Pretty, Ugly:
  local l1:
  option package:
 
  protect('i,j,k,epsilon'):
 
Pretty := proc(q::Vector)
  description "":
  return LinearAlgebra[Transpose](q)[1..4].Vector([1,i,j,k])+epsilon*(LinearAlgebra[Transpose](q)[5..8].Vector([1,i,j,k])):
end proc:

Ugly := proc(q)
  description "":
  local a;
  a := Vector(8);
  a[1]:=remove(has,remove(has,q,epsilon),{i,j,k});
  a[2]:=coeff(remove(has,q,epsilon),i,1);
  a[3]:=coeff(remove(has,q,epsilon),j,1);
  a[4]:=coeff(remove(has,q,epsilon),k,1);
  a[5]:=remove(has,coeff(q,epsilon),{i,j,k});
  a[6]:=coeff(coeff(q,epsilon),i,1);
  a[7]:=coeff(coeff(q,epsilon),j,1);
  a[8]:=coeff(coeff(q,epsilon),k,1);
  return a:
end proc:

end module:

savelib('MyQuaternions'):

Now I can load the module in a differnet maple worksheet "main.mw" by typing "with(MyQuaternions):"

The crucial thing now is the following: i,j,k,epsilon should be protected in "main.mw". I can do this by typing "protect('i,j,k,epsilon'):" Is there a way to tell maple to protect these variables automatically when the module is loaded? Or do I always have to type in the protect command by hand?

Thank you,

Josef

For application of object recognition with 3d sensor

plot3d(subs(c=1, a*b+a*c), a=-1..1, b=-1..1);
plot3d(subs(c=1, a+a*b*c), a=-1..1, b=-1..1);

after draw above two equations, they looked having similar structure

i find a book

Differential Geometry and its application John Oprea, page 98

having some measure to determine the shape, however they seems for

2 variables and need parametric form

how to use them to determine above two equations which have 3 variables

a*b+a*c  and  a+a*b*c

though not know the 3 variables version of below code, 

i think subs(c=1, a*b+a*c), subs(a=1, a*b+a*c), subs(b=1, a*b+a*c)

3 sets of equations after substitute third variables with 1, is it still possible to determine the shape?

EFG := proc(X)
local Xu, Xv, E, F, G;
Xu := <diff(X[1],u), diff(X[2],u), diff(X[3],u)>;
Xv := <diff(X[1],v), diff(X[2],v), diff(X[3],v)>;
E := DotProduct(Xu,Xu,conjugate=false);
F := DotProduct(Xu,Xv,conjugate=false);
G := DotProduct(Xv,Xv,conjugate=
false);
simplify([E,F,G]);
end:
UN := proc(X)
local Xu, Xv, Z, s;
Xu := <diff(X[1],u), diff(X[2],u), diff(X[3],u)>;
Xv := <diff(X[1],v), diff(X[2],v), diff(X[3],v)>;
Z := CrossProduct(Xu,Xv);
s := VectorNorm(Z,Euclidean,conjugate=false);
simplify(<Z[1]/s|Z[2]/s|Z[3]/s>,sqrt,trig,symbolic);
end:
lmn := proc(X)
local Xu,Xv,Xuu,Xuv,Xvv,U,l,m,n;
Xu := <diff(X[1],u), diff(X[2],u), diff(X[3],u)>;
Xv := <diff(X[1],v), diff(X[2],v), diff(X[3],v)>;
Xuu := <diff(Xu[1],u), diff(Xu[2],u), diff(Xu[3],u)>;
Xuv := <diff(Xu[1],v), diff(Xu[2],v), diff(Xu[3],v)>;
Xvv := <diff(Xv[1],v), diff(Xv[2],v), diff(Xv[3],v)>;
U := UN(X);
l := DotProduct(U, Xuu, conjugate=false);
m := DotProduct(U, Xuv, conjugate=false);
n := DotProduct(U, Xvv, conjugate=false);
simplify([l,m,n],sqrt,trig,symbolic);
end:
shape := proc(X)
local Y,Z,a,b,c,d;
Y:=EFG(X);
Z:=lmn(X);
a:=simplify((Z[1]*Y[3]-Z[2]*Y[2])/(Y[1]*Y[3]-Y[2]^2));
b:=simplify((Z[2]*Y[1]-Z[1]*Y[2])/(Y[1]*Y[3]-Y[2]^2));
c:=simplify((Z[2]*Y[3]-Z[3]*Y[2])/(Y[1]*Y[3]-Y[2]^2));
d:=simplify((Z[3]*Y[1]-Z[2]*Y[2])/(Y[1]*Y[3]-Y[2]^2));
[S(x_u)=a*x_u+b*x_v,S(x_v)=c*x_u+d*x_v];
end:
shape_matrix := proc(X)
local Y,Z,a,b,c,d;
Y:=EFG(X);
Z:=lmn(X);
a:=simplify((Z[1]*Y[3]-Z[2]*Y[2])/(Y[1]*Y[3]-Y[2]^2));
b:=simplify((Z[2]*Y[1]-Z[1]*Y[2])/(Y[1]*Y[3]-Y[2]^2));
c:=simplify((Z[2]*Y[3]-Z[3]*Y[2])/(Y[1]*Y[3]-Y[2]^2));
d:=simplify((Z[3]*Y[1]-Z[2]*Y[2])/(Y[1]*Y[3]-Y[2]^2));
Matrix([[a,c],[b,d]]);
end: