Dear guys!

I want to solve this system:

> c := 1: RC := 0.03: h := 1: m := 0.3:

> a := H(z)^2/(1+z)-h^2*(m*(1+z)^2+2*RC/(1+z));

> ode1 := diff(H(z),z) = (H(z)^4/((1+z)^2)+m*(1+z)*h^2*H(z)^2-2*m^2*h^4*(1+z)^4)/(2*H(z)*a) - (2*H(z)*h^2*RC)/(a*(1+z)^2) + (2*RC*h^2*(1+z)/(c*H(z)^2*a))*(H(z)^2/(1+z)^2-(H(z)^2/(1+z)-m*h^2*(1+z)^2)^2/(4*RC*h^2))^(3/2):

> ode2 := diff(M(z),z)=3*M(z)/(1+z)-2*M(z)*diff(H(z),z)/H(z):

> sys := {ode1, ode2}:

Dear all! I have 2 different lists:

ch1 := [[0.1e-1, -.56], [0.25e-1, -.57], [0.35e-1, -.555], [.115, -.43], [.16, -.3], [.195, -.24], [.28, -.155], [.315, -0.25e-1], [.32, -0.85e-1], [.41, .19], [.425, .11], [.425, .425], [.425, .43], [.425, .44], [.43, .12], [.43, .265], [.43, .405], [.43, .445], [.435, .295], [.435, .38], [.465, .44], [.5, .29], [.505, .31], [.505, .395], [.51, .37]];

ch2 := [[0.3e-1, -.5], [0.5e-1, .575], [.11, .495], [.15, -.295], [.19, -.33...

I want to plot the data with some error bars. I have tried the errorbar( ) function but it doesn't work. May I know what is the problem ?

Hi,

I have a quick question. I'm using OpenMaple under C and I am calling the "latex" function. I cannot get its output :( When checking the textCallback function, I get the command back as output (latex(%)). How could I solve this issue?

Regards,

Remus.

I don't know why maple can't solve this PDE

> restart;

> PDE := 4.2000*10^6*(diff(u[1](x, t), t))-.445*(diff(u[1](x, t), x, x))+4200.*u[1](x, t)+464.82-20836.*x-15.832*t+4.0442*10^5*x^2+2953.7*x*t+0.14631e-1*t^2+9.6788*10^6*x^3-2.7139*10^5*x^2*t-.99786*x*t^2+0.15902e-4*t^3-1.0085*10^9*x^4-6.3082*10^6*x^3*t-1069.3*x^2*t^2-0.15006e-1*x*t^3-3.9073*10^(-8)*t^4+2.3478*10^10*x^5+2.5874*10^8*x^4*t+1.2265*10^5*x^3*t^2+2.9028*x^2*t^3+0.17521e-4*x*t^4+1.9407*10^(-11...

I've been trying to find a way to plot error bars in a polar coordinate system. Using ErrorPlot i can display my data with error bars in cartesian coordinates but the usual option 'coords=polar' doesn't seem to be followed. Perversely, the option 'axiscoordinates=polar' does work in ErrorPlot, so i just get a cartesian plot of my data sitting on top of a polar axis. Is there a way to plot my data with errors in a polar basis?

I have had this problem on all of my computers ever since Maple 11, I believe. No matter the number of points in a spacecurve or DEplot3d command, the graph comes out with gaps. For example, this is the output from Maple 14:

Hi,
Consider the following DEQ:

x*y'+2y=1

Maple can solve this without problems with dsolve. But I want to use the Mellin Transformation for this, similar to the more common laplace transformation. The last step, the transformation back to the x-domain, does not work. Any idea why?

restart:with(inttrans);
mellin(x*diff(y(x),x)+2*y(x)=1,x,s);
solve(%,mellin(y(x),x,s));
invmellin(%,s,x);

Thanks

Dear Maple Users

I have encountered some strange behavior when trying to copy a vector:

In the first section I define a vector a and try to copy that vector and assign it to an variable b. Then changing the first coordinate in the copied vector b actually change the original vector as...

Is this the best way to extract the argmin with "minimize"? Thanks for your suggestions.

minimum := minimize( x^2, x = -1 .. 1, 'location' = true );
y_min := minimum[1];
x_argmin := rhs(op(op(minimum[2])[][1]));
                       0, {[{x = 0}, 0]}
                ...

Code
 

L:={NULL}:
for q from 11 to 100
check:=0:
for p from 1 to 200
n:=length(p):
for i from 1 to n
a[i]:=p[i]:
s:=sum(a[i],i=2..n)
if p-a[1]-10*s*modq=0 then
check:=check+1:
if check=200 then 
L:=L{op(L),q}:
print(L);

and the pseudocode:

1. L is the empty set
2. for q from 11 to 100
3. check=0
4. for p from 1 to 200
5.  find n, the number of digits of p
6. for i from 1 to n
7. find a[i], the ith digit of p

Dear,

How could we know which command to use to do a specific task such as:  "convert boolean value to {1,0}" . I know we could use evalhf() but if we search with keyword "convert true false to 0 1 " in the Maple help then we may not find the right command

Using the Online Help is a solution but I want to know an offline solution since I am not always with the Internet. Did anyone wrote a summary sheet with the content such as : (i.e a list of all commands with keywords for searching)

Ok, this mut have been asked a million times, but for the heck I cannot find how to do it:

I have a data file with many columns of data, delimiited, and many rows. I can read this in with ImportMatrix no sweat. The generated matrix has (row,column) format, i.e. matrix[1] is row 1 etc.

Now I want to plot two arbitrary columns against each other, say matrix[][19] vs matrix[][13] (the 19th column vs the 13. column). The data are monotonic in each vector so I can...

Hi,

Q1) Could you pls tell me how can I show in maple the curve (x^2+y^2)^2=x^2-y^2 in the form of

x(t)=cos(t)/1+sin^2*t and y(t)=sint*cost/1+sin^2*t.

Q2) how can I express sin^2(4x) in terms of powers of cosx.

a) cos^3(3x)cos(5x) as a linear combination of cosines of multiples of x.

how can i solve matrix ?

for example :