I am trying to write a program for calculating the number of ways to place k non-attacking rooks on an m x n board with restricted positions defined in B.  If i remove "option remember" the program works but it doesn't work very efficiently, and my goal is to extend this into three dimensions, so it needs to work fairly quickly in 2 dimensions.  The problem comes when I put in "option remember&q

To whom it may concern:

It appears that 'GraphTheory[Trail]' is missing from the Maple help function. Am I overlooking something? I am running Maple 12.01.

Cheers

Roberto

Dear all,

      I really really need a command for getting the inflection point of a expression. Thank you very much!:)

Best regards.

 

Dear all,

I use solve() to sove a equation group. when I typed the command and press Enter. there is no response even a error or fail. what is the reason?

BTW: the equation is complex.

Best regards!

What's the standard (or a cool non-standard)  way to compute the expected value of a matrix, e.g., a covariance matrix? Using this code:

restart; with(LinearAlgebra): e1 := Statistics:-RandomVariable(Normal(0, sigma)); L := [seq(e1*cos(pi*t), t = 1 .. 3)]; convert(L, Matrix); Transpose(convert(L, Matrix)); M := Multiply(%, %%); S := map(Statistics:-Mean, M)

how do I simplify S to the matrix of +/- one's and factor out sigma^2 outside the matrix? Thanks. 

 

Given four points in 2D, P1=(0,7), P2=(1,-12), P3=(7,0), P4=(10,-9), solve the following problems:

(1) Determine if P1, P2, P3 form a triangle;

(2) If they form a triangle T, determine if T is isosceles (two sides equal) and plot T;

Dear all,

       I am a newer for Maple. When I want to type some command in maple, I find that the default font is not very good. I try to change it, but when I type next exe group, I find  that the default font is recovered~~ How to change it forever?

Best regards,

 

 

I am having trouble with the following sum not adding properly:

sum(sum(sum(1/k!/j!/m!,k=2-m-j..2-m-j),j=0..2-m),m=0..2);

By my hand calculations, this should be 4 (?), but maple says it is zero. If we remove a factorial (like below) we will get a non zero sum. What am I doing wrong,or is this a bug in maple?

sum(sum(sum(1/k!/j!,k=2-m-j..2-m-j),j=0..2-m),m=0..2);

thanks.

I'm having trouble figuring out how to find the 2-D scalar potential of a 3-D vector field projected onto a plane.  The vector field is computed on the plane, coordinates (X,Y), as a vector function with arguments (X,Y,u), with 'u' being a parameter.

After invoking the VectorCalculus package and specifying

    SetCoordinates(cartesian[X,Y]),

I use the solve command to solve a quadratic equation. I get two outputs and want to assign the second output to the variable x. How can I do this?

Quadratic equation is 3x^2 - 9x+11

 

Thanks in advance!!

I have calculated data in form of a matrix. The corresponding x- and y-values are given in two lists (see attached file).

Now I would like to export the data to a textfile to use it in another program. The problem is, that I need the following format (name_listA[i]_listB[j]= is a text string where the corresponding x- and y-values are integrated)(values[i,j] is the number out of the matrix):

name_listA[1]_listB[1]= values [1,1]

name_listA[1]_listB[2]= values [1,2]

etc....

hi guys, i have the following set of equations e1='a2+a3+a5+a6-1=0'; e2='2*a1+2*a4+4*a5-1.6-2*0.2=0'; e3='a2+2*a3+a4-0.77-0.2=0'; e4='(K1*((a1+a2+a3+a4+a5+a6)^2/4)*(a5*f))-(a1^3*a2)=0'; e5='K2*a2*a4-(a1*a3)=0'; e6='K3*a4*a6-(a1*a2)=0'; symbolic a1,a2,a3,a4,a5,a6 I can slove these set of equations for known values of K1,K2,K3 but i have a set of values for K1,k2,K3 (35 values) ie K1=[1 2 3 4.......35] K2=[1 2 3........35] K3=[1 2 3 .....35]

I have the next problem, i need to  use recursion to make the equation E(x+1)=E(x)+(E(x)*(P-E(x)))/P*10 with P 15000 and E(1)=1, i put for example E(20), but maple only use ram, but doesn't do anything.

 

Thanks

I got a set of 8 variables and 8 equations, i need to solve them. I tried using "fsolve" but there are too many variables and too many equations. I thought I can try it using linearalgebra.
 

Dear all,

I am using version 12. I would like to sort a list of lists of  integers in respect to some of the terms of the sublists.

For example, the list

[  [3,5], [2,10], [9,1], [4,2], [7,3]  ]

would be sorted as:

[  [9,1], [4,2], [7,3], [3,5], [2,10]  ]

in respect to the second variable.

Actually, I found that the sort command with  the 'lexorder'[n] option would exactly this, except that it

seems that it doesn't work with numbers, but only with letters.

Any ideas?