I would like to plot the following singular double integral, but I cannot due to singularities...

where x>0, t=0.2 and m=0.2.

I defined f(y) function as f:=y->exp(-(y-4.68)^2/0.4):

I attached my file:
1st_try.mw

Thank you !

There is an error in my implementation as follow:

"Error, (in unknown) incorrect syntax in parse: `*` unexpected (near 1st character of parsed string)"

What I have to do to remove this error?

Hi, 

I have to plot in 2 different ways an ellipse that has been rotated in a plane. The equation of the ellipse is 

3x^2 - 3xy + 6y^2 -6x +7y =9

First of all I use the implicitplot which works great: 

restart;
f:=(x,y)->3*x^2-3*x*y+6*y^2-6*x+7*y-9;
with(plots):
implicitplot(f(x,y),x=-10..10,y=-10..10,numpoints=50000,scaling=constrained);

For the second method I really am not sure if what I'm doing is good. I tried with the plot3d, but it gave me some sort of weird shape, I really don't think it is what I am looking for. 

restart;
f:=(x,y)->3*x^2-3*x*y+6*y^2-6*x+7*y-9;
with(plots):
plot3d(f(x,y),x=-10..10,y=-10..10);

The I tried to reduce the equation to the form x^2/a^2 + y^2/b^2 = 1, but I could not, maybe because of the rotation. Still, I tried to take the ellipse function from Maple with some empirical numbers I just tried to create an ellipse looking like the first one. 

restart;
with(plottools):
with(plots):
a:=2.29:b:=1.38:x0:=0.8:y0:=-0.5:
elli:=ellipse([x0,y0],a,b,color=blue):
display(rotate(elli,0.4),scaling=constrained);
This time I get an ellipse similar to the first, but I don't really think it is legit to do it that way, in a sort of trial-and-error.

So I was wondering if there was another way like implicitplot to create the graph of that ellipse. 

This is the code hw2_final.mw

This is the warning 

Warning, The use of global variables in numerical ODE problems is deprecated, and will be removed in a future release. Use the 'parameters' argument instead (see ?dsolve,numeric,parameters )"

How to solve it?

Hello everyone,

I am trying to extract the coefficients from a differential poynomial. In general, this poynomial is in two variables, say u and v along with their differentials, i.e D(u) or D@@2(u) or so on. 

Coefficients of this polynomials are rational funcitons.

For instance- consider the following example:

a(x)*v*u+v*D(u)-D(v)*u

then output should be [a(x), 1, -1].

Thanks for your help.

Hello,

I've got this error in my code and I don't know why as I didn't get it when I used a different xn function. Any help would be greatly appreciated! Thank you in advance!

Kind regards,

Gambia Man

Download First_part_fractal_determination_.mw

Explore the values of km digit(n,m) using km list for all m, 0 ≤ m ≤ 8.
Look at the output until you can make a conjecture that concerns the pattern
obtained for each fixed m, 0 ≤ m ≤ 8 using 

km := proc (n::posint, m::nonnegint)

local k,

mySum := 0;

for k to n do

mySum := mySum+k^m

end do;

return mySum

end proc

using a list km list(m,6,20) when m is not a multiple of 4, and km list(m,6,50) when m is a multiple of 4.

any help appreciated..THank you

i have this problem -> f'^2 -ff''=f'''-k1(2f'f'''-ff''''-f''^2)+Ha^2(E1-f') with boundary conditions f(0)=0, f'(0)=1, f'(∞)=0.

since it is a fourth order equation, but only three bcs, it does not produce unique solution. so the solution of the equation may be seek in form of f=f0(eta)+k1f1(eta).

thus the equation will become 

f0'^2-f0f0''=f0'''+Ha^2(E1-f0')

and

f1'''-Ha^2f1'-2f0'f1'+f0f1''+f1f0''=2f0'f0'''-f0f0''''-f0''^2.

boundary conditions are 

f0(0)=0,f0'(0)=1,f0'(∞)=0

f1(0)=0,f1'(0)=0,f1'(∞)=0.

i had been clueless in solving this problem. please somebody help me with this problem.

Dear all,

I have the function

y:=x->-9.8455282400*10^9142*exp(-(2/3)*x^(3/2))/(x^(1/4)*sqrt(Pi))+3.3889331940*10^(-9169)*exp((2/3)*x^(3/2))/(x^(1/4)*sqrt(Pi))+(16/153)*x^(7/6)*sqrt(Pi)*exp((2/3)*x^(3/2))+Pi*((1/2)*exp(-(2/3)*x^(3/2))*(-1+exp((2/3)*x^(2/3)))/(x^(1/4)*Pi)-(16/153)*x^(7/6)*exp((2/3)*x^(3/2))/sqrt(Pi));

how can I plot y versus x with x in the interval (1000, 1001).

First, it's simple to verify that y(1000)=0; y(1001)=1;  So (1000, 0) and (1001,1)  belong to our graph.

I tried plot( y, x=1000..1001); but there is no curves.

Thank you in advance to help me to plot the graph of this function.

with brest regards,

defining f:=(t,a,b,c)->a*b/c*t^2 how can I give values for a,b and c inside the plot command?

plot(f(t,a,b,c),t=0..10 ????)

Staffan

Hi Please I need help with making the output of my fslolve appear in a way that I can easily copy to an excel.

I am doing analysis for 3 countries and each time I produce a result I copy manually to excel and use 'text to column' and the 'transpose' excel options to arrange the results in order. I do this for almost 20 time because I want to see how hows in parameter affect the variables. is there a way I can convert this to a 32 by 3 matrix so that I can copy all at the same time instead of copying each variable at a time. here is my solve command

UK_SOL_FIRST:= fsolve(eval({eq||(1..32)}, Params_UK_FIRST), InitValue_UK_FIRST);
ES_SOL_FIRST:= fsolve(eval({eq||(1..32)}, Params_ES_FIRST), InitValue_ES_FIRST);
DK_SOL_FIRST:= fsolve(eval({eq||(1..32)}, Params_DK_FIRST), InitValue_DK_FIRST);

The Results

UK_SOL_FIRST:={A_ss = 14.36104896, C_ss = 1.445842138, I_ss = 0.3136706500,

K_ss = 12.54682600, K_v_ss = 125.4682600,

LT_ss = 0.01061009037, L_ss = 4.014721807, N_ss = 0.9307582996,

P_a_ss = 0.9336893751, P_ss = 0.8625403648,

Surp = 0.9890479879, U_b_ss = 0.1781599919,

U_ss = 0.1046105158, V_ss = 0.05052687912, W_max = 1.476989982,

W_min = 0.4879419937, W_ss = 1.826907218,

W_tilde = 3.478049987, Y_ss = 2.428417935, aa_ss = 21.67403493,

chhi = 0.4523413798, f_c_ss = 0.04880034560,

m_ss = 0.03536881539, p_d_ss = 0.9907986980,

x_T = 0.7023268636, y_d_ss = 10.57030302, y_f_ss = 1.174478111,

y_x_ss = 10.57030300, z_ss = 21.14060602,

Profit_ss = 4.094720376, phi_prod = 0.9753885739,

theta_ss = 0.4830000000}

ES_SOL_FIRST:={A_ss = 10.91702785, C_ss = 2.038687975, I_ss = 0.3058575000,

K_ss = 12.23430000, LT_ss = 0.1309315222, L_ss = 2.857497927,

N_ss = 0.8398656215, P_a_ss = 0.9680877046,

P_ss = 0.8638978804, Surp = 2.541617932, U_b_ss = 0.9095925505,

U_ss = 0.1819708847, V_ss = 0.03119500880, W_max = 3.252738093,

W_min = 0.7111201606, W_ss = 3.605202340,

W_tilde = 3.665280790, Y_ss = 2.367929032, aa_ss = 15.67939783,

betta = 0.9909865708, chhi = 0.2898275349,

f_c_ss = 0.6743530978, m_ss = 0.02183650616,

p_d_ss = 0.9939322922, x_T = 0.005556307841,

y_d_ss = 7.853422751, y_f_ss = 1.195945300,

y_x_ss = 7.978400682, z_ss = 15.83182343,

Profit_ss = 3.084421270, phi_prod = 1.009721394,

theta_ss = 0.1714285714}

DK_SOL_FIRST:={A_ss = 16.18893837, C_ss = 1.359886068, I_ss = 0.2487000000,

K_ss = 9.948000000, LT_ss = 0.02282780783, L_ss = 5.834365727,

N_ss = 0.9399351536, P_a_ss = 0.7054445707,

P_ss = 0.8796237740, Surp = 0.6511024854,

U_b_ss = 0.4572819488, U_ss = 0.08450316042,

V_ss = 0.03491187713, W_max = 1.293898615,

W_min = 0.6427961298, W_ss = 2.363825013,

W_tilde = 2.758200925, Y_ss = 1.755529412, aa_ss = 34.56310241,

betta = 0.9851712031, chhi = 0.4499333284,

f_c_ss = 0.1898151486, m_ss = 0.02443831399,

p_d_ss = 1.032636460, x_T = 0.1506134910, y_d_ss = 11.17773688,

y_f_ss = 0.9144278497, y_x_ss = 13.74561008,

z_ss = 24.92334696, Profit_ss = 4.926248216,

phi_prod = 0.7210969276, theta_ss = 0.4131428571}

Polynomial.mw

Hi all,

I want to rewrite the equation which is attached for you in order to have it in term of Nu. I want to write it such as below:

()*Nu^7+ ()*Nu^6+... +()*Nu+1=0

In the above equation the parameters in the parenthesis are function of k1&k2

Let say, I have two plots

P1:= plot(........):
P2:= plot(........):

We can display in one plot as

plots[display](P1,P2);

My question is, is there any way to combine these two plots into one and then display.

For example:  

P:= combine(P1, P2);

plots[display](P);

The reason for asking this question:

I am plotting multiple curves in a loop depending on some conditions but I can't display them in one plot. They are all appearing on different plots.

Hi, I'm new to Maple and I have to produce a recursive procedure with the nomenclature Puis:=proc(X,n::integer) which calculates X^n with:

for n<0   ->   1/(X^(-n))

for n=0  ->   1

for n being an even integer   ->   X^(n/2) * X^(n/2)

for n being an odd integer   ->   X*X^(n-1)

The procedure I produced is:

Puis:=proc(X,n::integer)
option remember;
if n<0 then Puis(X,-n);
elif n=0 then 1;
elif rem(n,2,x)=0 then Puis(X,n);
else X*Puis(X,n-1);
end if;
end proc;

i don't have any eror up to this point, but when I try to evaluate, only Puis(4,0) works

Puis(4,-1);
Error, (in content) too many levels of recursion
Puis(4,0);
                               1
Puis(4,3);
Error, (in content) too many levels of recursion
Puis(4,4);
Error, (in content) too many levels of recursion

I was wondering what was wrong with my procedure, I changed the 1/(X^(-n)) with X^n and X^(n/2)*X^(n/2) for X^n because it is equivalent. I think I should put some sort of initial value to limit the recursion, but with that kind of function i really don't know how. I also tried with the X^(n/2)*X^(n/2) for the even numbers, but it says Puis expects its 2nd argument, n, to be of type integer, but received 1/2.

Hello everyone!

This is a procedure which I have writern. I know I write false, X=x because in maple, x is a table.although I did write x::Vector. Can you help me? Sorry, my English is not very good! :( 

JACOBI.mw