I want to solve the int((y⁴+by²+c)^-1/2,y)-x and find y=h(x), where b and c are constants s.t. c>b²/4. Maple gives me complex Jacobi elliptic function as a result. But I am not sure that this integral has complex value. Am I doing something wrong or the result is really a complex valued function? Thanks.

Indeed my main question is: Plot y=y(u) where we have these two relations: int((y⁴+by²+c)^-1/2,y)=x and find y=h(x). Then evaluate int((h(x)-B)^-1/2,x)=u and find x=g(u). By using these relations plot y=y(u). :)

Here B is an arbitrary constant, but if necessary we can define a value for it. All the variables and constants are real.

I hope I manage to express myself. Thanks again.

Ok guys this is the problem i have a matrix wich is really the result of a semivariogram so it is like this 
thi is my semivariogram so i have to find the best model and fit it to it, i can't just throw a polynomial it has to be
spherical= h:= C((3/2)*x/a-(1/2)*x^3/a^3) 
expotencial=
Lineal= y:= p*x
or y:=p*x^a

so i want the maple to show me the variogram plot and the i select wich one of the models i will apply.
the problem is that i don't know how to apply the models so started something that could maybe lead to the values of C and A for the spherical and the xpotencial becouse the others too are easy.
------------------------------------------------------------------.--------------------------------------------------------
restart;
with(plots);
with(CurveFitting);
m3 := Matrix([[0, 0], [1, 2], [2, 5], [3, 7], [4, 10], [5, 14], [6, 15], [7, 15.4], [8, 15.8], [9, 16], [10, 16.4]]);
plot(m3);
Upsilon := C(1-exp(-x/a));
Upsilon := C((3/2)*x/a-(1/2)*x^3/a^3);
for C to 16 do
for a to 100 do
for x to 11 do
H := m3(x, 2);
R[C, a, x] := abs(Upsilon-H)
end do
end do
end do;
for r to 16 do
for j to 100 do
N[r, j] := sum(R[r, j, X], X = 1 .. 11);
if N[r, j] < 55 then
print(r, j)
end if
end do
end do;
k := 14*(3/2*((1/16)*xx)-(1/2)*xx^3/16^3);
multiple(plot, [m3, color = "Green"], [k, xx = 0 .. 11, color = "Blue"])
----------------------------------------------------------...................---------------------------------------
so in this code i rest the values of the model and the values of the matrix for differents C and a so i pick the min of the Sum to see wich C and a give me the min value but i didn't work quite well first is difficult to get the C and a and sometimes the new curve is just not similir to the semivariogram (Matrix) please help i tried 
k := NonlinearFit(C((3/2)*x/a-(1/2)*x^3/a^3), X, Y, x)
and 
k:=LeastSquares`(m3, v, curve = C*(1-exp(-x/a)))
but they don't let me because they aint linear on the parameters
please help 
if you are interested in this topic here is what i am trying to do but explained really well is for geological matters
http://www.kriging.com/PG1979/index.htm#Chapter_2+Part1

if want to help me use this matrix 
m3:= Matrix([[0, 0], [1, 1], [2, 3], [3, 5], [4, 7], [5, 8], [6, 9], [7, 10], [8, 10.5], [9, 10], [10, 9.8], [11, 9.8], [12, 10.5], [13, 10.89], [14, 11.2], [15, 10.6], [16, 9.85], [17, 9.45], [18, 9.77], [19, 10.15], [20, 10.7], [21, 10.04], [22, 10], [23, 10.85], [24, 10.7], [25, 10.94], [26, 10.81], [27, 10.33]])
for that matrix the spherical model is the best i know

goodbye

Very simple procedure:

Restart;

global a:=0.0065, R0:=1.225, T0:=273.16, gamma:=1.4, R:=287.04;

Spd :=proc(H, T1, IAS);

T:=T1+T0;

rho:=R0*(1-((a)/(T)*1000)^(4.26));

sigma:=T0/(T)*(1-(a/(T0)*H)^(5.26));

EAS:=sqrt((rho*IAS^(2))/(R0));

TAS:=EAS*sqrt(R0/(rho));

SpdSnd:=sqrt(gamma*R*T);

M:=TAS/(SpdSnd);

return M;

end proc;

Entering Spd(5000, 15, 400); with return I get

Spd(5000, 15, 400) in blue and not a numeric rsult.

Where am I wrong?

Martina

I have a table whose indices and entries are strings, as in:

    T := table(["green" = "gruen", "red" = "rot", "blue" = "blau"]);

Thus, T["green"] evaluates to "gruen" but T["asdf"] evaluates to T"asdf".

What is a good way to detect that "green" is a predefined index into the table but "asdf" is not?  I do it in a somewhat clumsy way, as in:

> has("green", [indices(T, 'nolist')]);
        true

> has("asdf", [indices(T, 'nolist')]);
        false

I suspect that there ought to be a less elaborate way of doing that.

I can't solve this problem, can someone explain me whats worng and how to fix it, here is what i've done:

with(plots);
with(DEtools);
sist := diff(x1(t), t) = -4*x1(t)+x2(t), diff(x2(t), t) = -x1(t)+7*x2(t);
    d                             d                          
   --- x1(t) = -4 x1(t) + x2(t), --- x2(t) = -x1(t) + 7 x2(t)
    dt                            dt                         


condi := [x1(0) = 0, x2(0) = 3], [x1(0) = 2, x2(0) = 1], [x1(0) = 7, x2(0) = 9];
        [x1(0) = 0, x2(0) = 3], [x1(0) = 2, x2(0) = 1],

          [x1(0) = 7, x2(0) = 9]
for i to 3 do sol[i] := dsolve({sist, condi[i]}, {x1(t), x2(t)}, numeric); gra := odeplot(sol[i], [x1(t), t], t = -1 .. 1); display(gra) end do;

http://www.gap-system.org/Manuals/doc/ref/chap50.html

which group do four differential electromagnetism belong to in library available in gap system? 

what is the order of the group?

do maple 17 have this group? how to show?

I'm currently having some difficulties in solving a system of differential equations numerically.

This is my code.

how to generate random data from equations of electromagnetism?

how to call matlab to run k means on the data and

how to show which circle do the row of data belong to?

is there a built in function which calculates the radical of a number?

e.g. 54=2*3^3

rad(54)=2*3=6

Dear Friends:

I am currently working on a calculation for phase velocity of acoustic waves and don’t get along.  

My equation has the following form:

equ := tan( (31 / 20000) * sqrt( -9610000/c^2 + 1) / Pi) / tan((961/1260000) * sqrt( -39690000/c^2 + 1)/ P i) = -(1191640000/63)*sqrt(-9610000/c^2 + 1)*sqrt (-39690000/c^2 + 1)/ (c^2*(19220000/c^2 - 1)^2)

Using ‘sol = solve(equ,c)’ returns

sol := 96100* RootOf(1 + (400000000 * Pi^2 * RootOf(40320000000000000000 * Pi^4 * tan(_Z)*_Z^4256000000000000 * Pi^3 * csgn(_Z) * _Z^3 * tan((1/157500) * sqrt(24806250000 * Pi^2 * _Z^2 - 45167) / Pi) * sqrt(24806250000 * Pi^2 * _Z^2 - 45167) -96868800000000 * Pi^2 * tan(_Z) * _Z^2 + 615040000 * Pi * csgn(_Z) * _Z * tan((1/157500) * sqrt(24806250000 * Pi^2 * _Z^2 - 45167) / Pi ) * sqrt(24806250000 * Pi^2 * _Z^2 - 45167)+58181823 * tan(_Z))^2 - 961)* _Z^2)

c should be in a range of 13,000.

Two questions:

1) How can I deal with _Z?

2) Any suggestion how I can calculate ‘c’? Maybe numerical?

I am relative new in maple…

Many thanks!

Alex

Hi,

Might be a silly question but how do I preview/display the expression I type instead of maple automatically solving it.

For example, If I type in '1+1' in wolfram, it displays 'input: '1+1'' right below it.

I would like to do this in maple but cant seem to figure it out.

Hopefully that made some sense.

Cheers and thanks! 

Let I=<3x^2+2xy+x, y-xy+3, y^2-2x+4> be a polynomial ideal in K[x,y]. I want to form a matrix M corresponding to this ideal as the following:      

                                 x^2     xy     x      y^2      y      constant

                               -----     ----   ----    ----     ----     ------

                                  [3       2       1       0       0           0]

                             M= [0      -1      0        0       1           3]

                                  [0       0     -2        1       0           4]

Please note that in the first, the all monomials appeared in generators of I,  sorted by lexicographic ordering x>y. How can I from matrix M from polynomial I?

Hello,

  I have a complicated task. Suppose there is a file, its content is

1

A    3
0.8 0.2

0.6 0.3

0.5 0.4
****
2
A   3

0.8 0.2

0.6 0.3

0.5 0.4

****

  I want to read the file for each line, and store the content in each variable, e.g. "S" and 3 for two different variables, respectively. 

By using 

Nn:=readline("file");
Nn2:=readline("file");
Nn3:=readline("file");

parse(Nn);

parse(Nn2);

For N2, it does not work "Error, incorrect syntax in parse: unexpected number (near 6-th character of parsed string)"

How to read such a file properly including varies of content? Thanks a lot!