does any one know if it is possible to solve numerically a ODE sys write in matrix form without first evaluate is as a set of equation?

for example my system is y'(x)=A(x,y).b(x,y)
where y'(x) and b(x,y) are Vectors and A(x,y) is a matrix

so i would solve it numerically without doing first the dotproduct symbolically. I woud do this because my system equation is constitudet not from a simple matrix.vector but by large matrix inversion so do it symbolically first take a lot of time and memory.

When I do an integral Maple sometimes spits out ridiculous answers.... I don't have an example off hand but oft it will give me trig functions that it SHOULD evaluate. Last night at my lab I was trying to do a taylor series that involved sine squared and to the fourth, and instead of giving me NUMBERS like I needed it left it in terms of sine which was utterly useless to me!

How can I assign an argument to the real numbers in an interval?

I have a matrix M which is 3x4.  I need add a fourth row to it.  I've been trying

 

E:=Matrix([ [M], [0,0,0,1] ])

and

E:=Matrix([ [Row(M,1)], [Row(M,2)], [Row(M,3)], [0,0,0,1] ])

But neither of them worked.  How would I do this?

Thanks,
Dave

Hi, I am trying to find a general solution for a special case of the 4x4 Riccati Equation. My worksheet chugs for 5 hours and 2gigs of memory before crashing. Am I posing the problem incorrectly? Or will more memory help (and if so, how much memory)? > with(LinearAlgebra); > A := Matrix([[ZeroMatrix(2), IdentityMatrix(2)], [ZeroMatrix(2), Matrix(2, symbol = a)]]); > B := Matrix([[ZeroMatrix(2)], [Matrix(2, symbol = b)]]);

Hi all,

 

 

Hi all! Please help me to simplify the following expression: ex1 := C10*C20*a^2+2*C10*C20*a*b+C10*C20*b^2-m*u^2*a*C10+m*u^2*b*C20+1/2*e1*e2*a^2+e1*e2*a*b+1/2*e1*e2*b^2; 1, I've tried the followings: collect(ex,e1*e2); Error, (in collect) cannot collect e1*e2 2, then I've read some advice here in the forum, and tried this: subs(e1*e2=z,%); collect(%,z); S0_temp2:=subs(z=e1*e2,%); This doesn't works as well. It simply doesn't substitutes z for e1*e2. My goal would be to get something like this: (a+b)^2*(C10*C20+1/2*e1*e2)-m*u^2*(a*C10-b*C20); Thanks!

Hi,

I'm just playing about with Maple's functions to see what they do. I'm confused by the behaviour of "evalb". When I enter:

I want to learn how to analytically and graphically analyze discrete time recursion equations such as the following: N(t+1) = (1+b)(1-d)N(t) in Maple 12 because Mathematica decided to crap out on me right before I have to give a professional talk (SHAME ON YOU STEPHEN WOLFRAM!!). Does anybody have a good direction to point me in? Basically, in Mathematica, what I would do is: N[t_, b_, d_]:=N[t,b,d]=(1+b)(1-d)N[t-1,b,d]

hey i'm trying to learn how to use maple and can't seem to figure out why this is wrong. i don't really know what "nops()" does either. 

 

with (linalg);

*insert equations, matrix and Groebner here and get a whole bunch of z values *

 

zvals:=[fsolve(polz)];

for i from 1 to nops(zvals)

  Error, unterminated for loop

do

   Error, unable to parse

myx:=zvals[i];

 

The text below was encrypted with a substitution cipher. Only the letters (both
upper-case and lower-case) were substituted, leaving punctuation and spaces alone.
Can any on help me to figure out what the original message was using maple procedures.
“wA’r aBeD WUeK AP XNaB NM U rALKNP USUeAJBMA NM zUM
nPrB ZNAW U JUM ZWP’r XBUeMNMO AP SXUD AWB aNPXNM.”
yWUA’r ZWUArWBAPXK AWB SPXNCB ZWBMrWBWUMKBK AWBJ
AWB BJSAD eBaPXaBe.
lNCWUeK heULANOUM, “yWB zCUeXUAAN yNXA”

I have no clue...

How do you calculate the final velocities and the angles when two objects collide into one another...any help/info would be highly appreciated.

When storing an inequality, Maple seems to always convert it to less than or less than or equal form.

x:=a>b  => x:= b<a;

Is it always true? Can someone explain a little bit how maple stores its data?

 

Thanks,

Peter

 

so far i plotted functions where z values were functions z=f(x,y) in cartesian coordinates. this was easily done with the plot3d command. now i have a function described in polar coordinates, z=f(r,phi). so far i haven't succeded in plotting it. as far as i see it cylindrical coordinates would be required here, but maple expects r=f(z,angle) and i need z=f(r,angle). maybe a changecoords operation would help, but I'm not sure how to perfrom that (I've just started using maple). would be thankful for pointers on how to tackle my problem.