I am trying to create a plot for two differential equations but I'm not getting any graphs with the commands below. I'm not sure what's causing the problem and I've tried everything I can think of. Please help if you can. a := 2*ln(2) b := 1/5*ln(2) dose := proc (t) options operator, arrow; sum(2*Heaviside(t-6*n)-2*Heaviside(t-6*n-1/2), n = 0 .. 10) end proc J:=DEplot([diff(x(t), t) = dose(t)-a*x, diff(y(t), t) = a*x-b*y], [x, y], 0 .. 50, {[0, 0, 0]}, stepsize = .5, scene = ([t, x])) K:=DEplot([diff(x(t), t) = dose(t)-a*x, diff(y(t), t) = a*x-b*y], [x, y], 0 .. 50, {[0, 0, 0]}, stepsize = .5, scene = ([t, y]))

Suppose I generate a PLOT3D structure by p:= plot3d(f(x,y),x=-1..1,y=-1..1,grid=[3,3]): p2 := convert( p, POLYGONS ); Now I want to go through these polygons and throw away those that have a vertex far away from the origin (say more than 10 units), and then redisplay the trimmed structure. Is there a snazzy way to do this?

Hi, I use maple 11 on linux ubuntu. When I try to save a package that I've done, with the lines: mypackage:=module() global... export... option package; BODY end module(); savelib(mypackage) or savelib('mypackage') maple return the error "error, cannot open archive, /home/salvatore/maple11/lib/, for writing" the address is the good one (I can load all the preexistent package). Someone can help me? Tk you S.

Hi, I use maple 11 on linux ubuntu. When I try to save a package that I've done, with the lines: mypackage:=module() global... export... option package; BODY end module(); savelib(mypackage) or savelib('mypackage') maple return the error "error, cannot open archive, /home/salvatore/maple11/lib/, for writing" the address is the good one (I can load all the preexistent package). Someone can help me? Tk you S.

Usually I work with classical interface, but the java interface has some nice features which I want to use for printing. Thus I open my *.mws worksheet as a *.mw and want to do just that. However I have some problems, may be I am just too awkward here: 1. My mws output is 2 D and always non-italic, however in mw it tasteless shows up as italic. I tried to change that, but there exists no way just to say it to the character (one only can activate a check box to *make* it italic, not conversely). The only way was to select all the sheet and then de-activate italic through the menu bar.

I solve recursively a series of linear systems of ever increasing number of unknowns, proven to have a unique solution, each of which is expressed as a function of all the previous unknowns. So Y[i]=sum(c[i][j]*X[i][j],j=1..nops(X[i])), and most c[i][j]'s are nonzero. I successfully used solve(Y[i],X[i]) and SolveTools[Linear](Y[i],X[i]) to get each Y[i] solution but, as i increases, the solution time increases exponentially. For example, in my system (P4 2.66GHz, 2GB RAM) solving a system of 15 variables takes about 6 seconds, while one of 21 variables needs about 250 seconds! Is this to be expected? I need to solve to about 40 variables this way but it doesn't seem possible with solution time increasing at this rate.

Sorry, I guess that less-than, greater than are not allowed directly in posts. In Maple10/11 there is the new statistics package, which is pretty cool. And there are lots of examples on how to create a custom continuous distribution, but not on creating custom discrete distributions. for example: U := Distribution(PDF = (t -> piecewise(t < 0, 0, t < 3, 1/3, 0))); Is a great example of creating a continuous distribution, but how can I create something similiar that is discrete? Any examples are appreciated!! Thx Cameron

I have a matrix for which the elements have imaginary components which are quite small. For purposes of readabililty I removed the imaginary components as follows: A:=map(x->Re(x),A); However, I was wondering - Is there any I could have displayed the matrix showing just the real components without actually getting rid of the imaginary ones? Also, the components are displaying to 10 decimal digits which is awkward. I know if I set Digits:=5 for example, the diaplay would be more readable but I don't want the calculations to be done with that level of precision. Is there any way I ca

How do I use maple 11 to solve the following problem? I am trying to upload my graph however the system is not allowing me to do so. Any pointers? The question is: Use Prim's algorithm to find a minimal spanning tree for the weighted graph. Give the weight of the minimal spanning tree found

How do I use Maple 11 to determine if my graph is a rooted tree, as well as draw the rooted tree with the root at the top without the arrow heads.

How do I use Maple 11 to determine reverse Polish notation or postfix form? I can't find a example worksheet in order to plug-in my problem.

Maple needs commands to interpolate and plot large data sets. Consider the following:

# generate data
data := convert(LinearAlgebra[RandomMatrix](10000,2,generator=-100000..100000),listlist):
data := sort(map([op], [op(op(table(map(`=`@op, data))))]), (a,b)->evalb(a[1] < b[1])):
data := Matrix(map(proc(a) [a[1],a[2]/200.] end,data), datatype=float[8]):

# now suppose I take this data and...
f := CurveFitting[BSplineCurve](data, x);
plot(f, 0..100);

Someone trying to do this with real data (and 10000 points is small) will experience the following problems:

Maple needs proper sparse linear algebra. That means a data structure where row or column operations (good luck getting both) can be done in linear time and algorithms such as structured Gaussian elimination or iterative methods run in O(A) time, where A is the number of non-zero elements in the matrix.

Maple 11's implcitplot command contains a cool option to reduce the line count of a plot. I would like a separate command for this, along with the corresponding generalization (level of detail) to 3d plots. I think it would be good to apply this sort of thing automatically to make plots faster and also to make larger more detailed plots possible. I also think that the 3d plot facility is far too limited in terms of the number of polygons it can handle. It should be replaced with something capable of "millions of triangles per second", because that's what any $10 integrated graphics chip ca

A colleague has asked me this: The integral int(exp(-x)/sqrt(x^2-1),x=1..infinity) is equal to BesselK(0,1). Is it possible to get Maple to make this evaluation? I (or he) would be grateful for any ideas.