I have defined a sparse matrix and verified that it is space by using the command- sparsematrixplot(Kd,'matrixview');

first, is there another way to check wether the matrix is stored in the sparse form?

second, when trying to sovle an algebraic set of equation using the procedures for hendling the sparse matrix i encountered the following error:

Error, (in HWcall[1]) column vector dimension less than length of sparse data
 

what is the meaning of this error and how can I repair it?

Dvir
 

 

Hi, there were already some topics about labeling plots but I have still a question:

I would like to label my axis with e.g.: rho [kg/m^3]. roh should be displayed symbolic (2D output) as well as m^3. On the other hand I would like to avoid that Maple builds a (2D) fraction with kg/m^2. Does anybody know how to do this?

The other thing: Is it possible to add an legend to a 3D plot?

Thanks!

how can i calculate all roots(or some roots in a given interval, or the J th root) of a (real or complex) trigonometric periodic equation?

I need to multiple two functions, and the two functions has to do with filling indices (X,Y) which will in turn generate a matrix. please how do i do it.

Please, the scroll button on my mouse does not work with maple. please is it a bug in maple or there is something i can do about it. Thanks

Hi, all, I have a question about how to evaluate result of expression containing ROOTOF. for example: >alias(x = RootOf(Z^3+Z+1)) >A := a[2]*x^2+a[1]*x+1 >B := b[2]*x^2+b[1]*x+1 >M1 := A*B; >expand(M1); a[2]*x^4*b[2]+a[2]*x^3*b[1]+a[2]*x^2+a[1]*x^3*b[2]+a[1]*x^2*b[1]+a[1]*x+b[2]*x^2+b[1]*x+1 >evala(expand(M1)); x^2*(1+b[2]-b[1]+a[2]*b[1]*x+a[2]*b[2]*x^2+a[1]*b[2]*x+a[1]*b[1]+a[2]-a[1]-a[1]*x^2-x^2*b[1]-x+x^2) I have questions about expand(M1) and evala(expand(M1)). >expand(M1); a[2]*x^4*b[2]+a[2]*x^3*b[1]+a[2]*x^2+a[1]*x^3*b[2]+a[1]*x^2*b[1]+a[1]*x+b[2]*x^2+b[1]*x+1

Dear Sir:

I have the below sum equation.

Please make some correction to get a solution.

 

with(student);

v:=(w[j])->sqrt(Sum(A[i]*cos(w[j]*t[i]),i=1..n)^(2)+Sum(A[i]*sin(w[j]*t[i]),i=1..n)^(2));

v(w[j]); diff(v(w[j]), w[j]);

value(%);

 

Thanks

I have this code: ade:= diff(y(r),r,r)+2*diff(y(r),r)/r+486*polylog(3/2,-exp(1-1/43*y(r))) = 0; ys:= dsolve({de, y(0) = 0, D(y)(0) = 0}, y(r), series, order=10); yn := convert(evalf(ys), polynom);yn1 := eval(yn, r = .1); dyn1 := eval(diff(yn, r)); dyn2 := eval(dyn1, r = .1);S := dsolve({de, y(.1) = 1.266393114, (D(y))(.1) = 25.18200436}, y(r), numeric);with(plots); odeplot(S, [r, y(r)], r = 0.1e-1 .. 200); # I get a plot from this step, but I need an expression for y(r) also. A crude method is to get S(1);S(2) and so on and copy paste those values for interpolation.

Good day,

Before this I've run my programme (n=2 and 3), it's ok. But now, when I run the same programme (for n=4), it's got error, why?. This is my programme.

> isom:=proc(A,B,n)

locali,j,k,s,r,eqns,t,ISM,BChange,sols,l,S1,S2,C;

C:=matrix(n,n);

BChange:=matrix(n,n);

ISM:=0;

eqns:={};

for i to n do

for j to n do

for l to n do

S1:=sum(A[i,j,k]*C[l,k],k=1..n);S2:=sum(C[p,i]*(sum(C[r,j]*B[p,r,l],r=1..n)),p=1..n); eqns:=union(eqns,{S1=S2})

end do end do end do;

sols:=[solve(eqns)];

Hello

Given following list:

vec := [[`@`(1, {.34}), `@`(2, {.4})], [[], 1], [[], 2], 3];

Applying the indets function to vec[1] yields

indets(vec[1], numeric);
              {1, 2, 0.34, .4}

Given a list where we have identical elements (in this case the floats)

vec := [[`@`(1, {.4}), `@`(2, {.4})], [[], 1], [[], 2], 3];

The following yields

Hi all,

I have Maple 13, and I am learning how to use it.

To start with it, I was trying to resolve the values of X and Y in the following equations:

(1): X + Y = 60

(2) X = Y -12

and here were what I input into Maple

matlab has the following command:

axis ([-inf inf -inf inf])

where the inf means (something like) "the largest value" and -inf "the smallest value". With this command, you can set the dimension of the axes without having to enter the actual values, which is then robust to changes in parameter values. This is most useful in situations where some of the values are to be fixed and others left to the simulation, say:

axis ([0 inf -inf 1])

What would be the Maple equivalent or workaround?

many thanks.

Hi acer,

I got the problem of "Int vs int" again. With your advice, I changed from "int" to "Int" in the f2 expression below and draw the graph

However, the "memory allocation failed" message appeared again after long time running. Did I understand something wrong?

Here is the expression I want to draw the 2D graph

f1:= d*exp(-(0.5*(u-s-k))^2-(0.5*(u-s-k)+t-u)^2+(0.5*(u-s-k))^2+(-d*k));

Hello,

I've seen a topic or two similar to what I'm trying to do, but not exactly the same.  Their solutions didn't work for my issue.

Long story short, I need a function plotted on a loglog scale with certain points on this curve to be actual points, just like a scatter plot on top of a function.  Let's assume I've got a function f(x) and I have a list of some values for x.  I'd like a loglog plot of f(x) as well as points for each of my 'x' values to be actual points that lie on f(x).

Hi all, I solved this nonlinear DE de := diff(y(r), r, r)+2*(diff(y(r), r))/r+9*(16*43)*Pi^2*sqrt(Pi/(2*(1/43)^3))*polylog(3/2, -exp(1/43*(43-y(r))))/(16*Pi^2*sqrt(43)^3) = 0; with initial conditions y(0) = 0, D(y))(0) = 0 by using truncated series method in 'solve symbolically' option (Dsolve[interactive]). I am getting a solution like this: y(r) = -(3/4)*sqrt(86)*sqrt(Pi)*polylog(3/2, -exp(1))*sqrt(43)*r^2-(1161/80)*Pi*polylog(1/2, -exp(1))*polylog(3/2, -exp(1))*r^4+O(r^6). How can I get an asymptotic potential y(r) for r-> infinity? Thank you MS