This tip comes care of Dr. Michael Monagan at Simon Fraser University. Represent your sparse matrix as a list of rows, and represent each row as a linear equation in an indexed name. For example:

A := [[1,0,3],[2,0,0],[0,4,5]];

S := [ 1*x[1] + 3*x[3], 2*x[1], 4*x[2]+5*x[3] ];

To compute the product of the matrix A with a Vector X, assign x[i] := V[i] and evaluate. This can be done inside of a procedure because x is a table.

V := [7,8,9]: for i to 3 do x[i...

I am trying to use the subs command to take a general solution to a differential equation and apply some numerical values. I can't seem to get the system to recognize the values I am substituting for. Consider the following: m*diff(y(t),t,t)=-m*g+sigma*A*diff(y(t),t); (1) y(0)=h,D(y)(0)=0; (2) dsolve( {(1),(2)} ); (3) subs( {A=2,m=50},rhs((3)) ); Everything works fine. If, on the other hand I impose any kind of constraint on A or m in the original equation then the substitution fails (nothing happens). Clearly the system has tagged the value for A and m as something other than their original name. Since the system doesn't report this name change how can I make substitutions after a symbolic manipulation like this?

Hi,
I'm new to Maple so please forgive me if this seems really easy but I can't seem to find it in help anywhere. Basically, I have an equation that is a function of x, y, and t (where t is time). Instead of a 3-D plot, I would like to display a 2-D plot with x-axis and y-axis and have 5 lines of the equation at various intervals of t (t=0, t=1, t=3, t=5, t=20, etc.).
Thank you very much for the help,
KC

Does anyone know if there is a way to save plots in a maplet?
The following does not produce the expected .ps file:

In response to a

question about collecting symbolic powers of polynomials, I suggested a few lines of code that solved the particular problem. Following is a procedure that enhances the technique to mimic, to some degree, the abilities of Maple's

**collect** procedure, which handles integral powers. This enhanced version can take a list of indeterminates. It also permits use of an optional third argument,

**func**, that is applied to the collected coefficients of a power.

hey all,i finding how to solve integration on maple rather tricky.I need 2 find the numerical area of the region above the x-axis which is restricted by the curve y=5sinx-3x^2+5 and the x-axis. how can i do this? any suggestions will be gratefully received.

Hi, i'm new to using maple, and so far been ok solving equations, by figuring out the code forthis has got me stumped and would appreciate any help people can give me. basically i'm trying to find the smallest value of x>0 for which the function f(x)=sinx/x has a minimum and to find the coressponding value of the function. However i keep getting error messages, as my code probably does not make sense. could any one help pls? thanks.

hi, I want to solve linear equations with the assumption that Maple round every step of the evaluation accurate to 2 decimal places. for example: > solve({1.11 x - 2.13 y + 1.14 z = 1.23, 0.32 x + 1.44 y + 3.02 z = 4.10, 1.27 x - 1.14 y + 2.54 z = 5.67}, [x, y, z]) x=19.59 y=7.38 z=-4.24 and not [[x = 19.09759807, y = 7.184806478, z = -4.091838645]] thx for your help

Does anybody know of a way to extract derivatives of a specified function from an expression? For example, if I have the expression,
int(D[6](F)(x,t,y(x,t),diff(y(x,t),x),diff(y(x,t),t),diff(diff(y(x,t),t),x))*diff(diff(yv(x,t),t),x),t = t1 .. t2);
I'd like to be able to get the derivatives of yv(x,t) which in this case would be,
diff(diff(yv(x,t),t),x).
I ask because I'm trying to systematically integrate a set of expressions by parts where I know that the dv term always contains a certain function's derivatives and I can stop integrating by parts once I have just the function.

Hello, I am new to maple and I am trying to create letters with the arrows and hats over them so they can represent vectors. I looked at all of the different fonts included in Maple and none of them that I saw had any characters with arrows over them. I looked at all of the shortcuts and I didn't see a way to type stuff directly above a letter, beacuse maple has letters and it has arrows so if there were a way to do a superscript of the arrow except directly over the letter that would work. I also looked at the symbol definitions, and I looked through maple help. I found an overwhelming amount of help for the commands, but nothing for a simple formatting issue.

How much is MapleSoft charging High School teachers for a copy of Maple 10? Do they get the full version??

I tried to install Maple 10. At the end the Maple installer prompts me to restart my computer. ONce I press the restart button , the installer just sits there. I rebooted the machine by depressing the on/off button. Maple seems to be working on my computer for now. Should I install Maple again (after removing it) or should I leave it alone? Has anyone else experienced the same installation situation?? Thanks!!

Hi, I'm having trouble getting the collect function to do what I want. Namely, I would expect collect( a*x^b + x^b, x) to return (a+1)*x^b. Here, a and b are variables. Collect only seems to work if either a or b has a defined value (e.g. a=2, b is undetermined). What am I doing wrong here?

I have the following: arrays arrC of type double in a C code and a fct
in Maple allowing arrM of type Array(datatype = float[8]) as argument.
I want to evaluate the fct using arrC as input. For that one can either
use 'MapleAssignIndexed' (looping through the elements if there are not
very much of them), or 'RTableCreate' (details omitted).
Both seem to need some overhead which costs time.
Is there a way to use something like the C function memcpy to copy the
array to Maple (assuming the correct space can be supplied) to speed it
up? Does one have to work with byte arrays instead for that - or is it

Hi!
The Maple 10 installation worked fine. No problems at all. I've installed the 2 updates 01 and 02. The command line maple works. BUT xmaple denies to start. I see no error message. May a java related problem which I am not able to fix myself.
Help is very apreciated!
Regards, Arno