Why is this happening?

Thank you!
mapleatha

I have modeled a delta type parallel manipulator for performing CPR operation.

The model does 100 compressions per minute with a vertical displacement of 4-5 cm, which is the requirement of the CPR.

A rigid body is attached to the end effector and I need to model a human chest using a spring damper system.

The exists a spring-damper block in the 1D Mechanical translation category. I have previosly modeled a spring damper mechanical system using these blocks but I have never tried connecting these to a Multibody.

The spring and damper coefficients of a human chest are k=8350 N/m and c=500 Ns/m.

My model is here:

Can you help me model the human chest?

how to find infinitisimals of system of differential equations?

i have system of two dependent variables and two independent variables.

[-(diff(psi[2], x))+diff(psi[1], t, t)-2*n*(psi[1]^2+psi[2]^2)*psi[1]-beta*(diff(psi[1], x, t)) = 0,

diff(psi[1], x)+diff(psi[2], t, t)-2*n*(psi[1]^2+psi[2]^2)*psi[2]-beta*(diff(psi[2], x, t)) = 0]

Here is a possible situation tha appears very often in presentations:

How do I add a colon ":" after "ss3" in the second red line? And, while we are at it, how do I add the word "and" between ss2 and ss3?
Thank you all so much for your continuous and inexhaustible help!

mapleatha

Question:I've defined wave, but it's after that it gets sticky. This is my attempt:As you can see, not very fruitful. I have tried wave(x=-infinity..infinity, t=-infinity, infinity) which returns an error. 

When i sub in wave(1,1) i get an answer, or any other number for that matter, but I'm not sure how to actually aswer this question. 

Any and all help appreciated

Thank you

Question: You will observe that the two curves intersect at one or more places in the displayed region. Use fsolve to find the (x; y) coordinates of all the points of intersection in this region.

In theory this question has a very simple answer, but i am struggling no end finding it. 

P1 := y^2 = x^3+x^2

P2 := y = 2*x+1

This is what the graph looks like when plotted, and as we have already got the two equasions assigned as H and J, i just type in fsolve({P1,P2})? 

Apparently not, as this returns {x = 4.048917340, y = 9.097834679}, which is correct, but is only one of three points of intersection, and just so happens to be the one not shown in my plot (although it is still a valid point of intersection) and i need the ones within the region i have set for the graph (x=-1..2 and y=-1..1).

How do i get maple to show me the two points of intersection i need using the fsolve command? 

I've tried rearranging the equasions for y, rearranging for x, adding an option to solve for x [fsolve({P1,P2},x) but this returned an error] and am pretty stumped. For something so seemingly simple i dont really know where to turn.

Thank you :)

i have a matrix m[10,10] with some values, i want to PointPlot every rows with Explore command , here is my code:

Explore(PointPlot(m[a, 1 .. 10], [.1, .2, .3, .4, .5, .6, .7, .8, .9, 1]), parameters = [a = 1 .. 10]) 

but it does'nt work! how can i fix it?

thank you in advance

Hello!

I have the following situation that I'm having trouble with . I am a total beginner in Maple, btw.

I have a long equation, involving a variable (x) , several other variables, and a function of x, F(x). A priory, this function is unspecified (its a probability density function, that may depend on whichever distribution it follows). I would like to have Maple operate on this function as if its a function of x, but without specifying. For example, lets say I have

x + yF(x)=0

I would like to derive it and have Maple return me

1 + yF'(x)=0

Is this possible?

Thanks!

Download Matrix_formulation.mw

When i input: i get returned.and with this i have no idea what im supposed to do. I dont understand what it means, how to correct it or how to actually answer the question using the information. 

This is what i am returned with when i try to input a sequence using my previous result.

Could someone please put me on the right tracks and help me with this problem?

Thank you

Hi, 

I'm new to maple and have a problem when using the dsolve in a for loop. I get the error message Error, (in dsolve/numeric/process_input) the independent variable (t in phi(t)) cannot be a procedure name and I dont now why. 

The code design is 

for k to kk do
vars := x(t), y(t), phi(t);
ic := x(0) = xx, y(0) = yy, phi(0) = zz;
sys := diff(x(t), t) = y(t),
diff(y(t), t) = -2*gamma*y(t)-alpha*x(t)-beta*x(t)^3+F*cos(phi(t)),
diff(phi(t), t) = 1;
sol := dsolve({ic, sys}, {vars}, numeric, output = listprocedure, numeric = -1);
assign(sol);
x := x(t);
y := y(t);
phi := phi(t);
numpts := 50;
pts := seq([x(2*Pi*i), y(2*Pi*i)], i = 1 .. numpts);
plt(k) := plot([pts], view = [-1.5 .. 1.5, -.5 .. 1], color = black);
xx := 'xx'; yy := 'yy'; zz := 'zz';
xx := x(2*Pi*numpts);
yy := y(2*Pi*numpts);
zz := phi(2*Pi*numpts);
unassign(x, y, phi);
c := x(0) = xx, y(0) = yy, phi(0) = zz
end do

Let's say you have a m times n matrix and you want to ask Maple to computes all of its p minors (p smaller than minimum of m and n). Is there any prepared command for it at Maple? I can write a procedure myself, I just want to know if there is a command in Maple or not. The minor command in LinearAlgebra package is just computing determinant of a square matrix after removing a given row and a given column which is not what I'm talking about.

Hi all,

I am totally stuck in the question:

I can do it for seperate cases, but how to do it, with somekind of sequence

Integral for x= 0 to infinity of [2 sin(x/2)/x] ^ 2n 

this has to be equal to:

2n* pi (sum of [(-1)^j * (n-j)^(2n-1)] / [j! * (2n-j)!]

I showed it for j=0 and n=1

But how to do it for n =1,2,3 and 4

Dear all

I need a help to finish just two lines in my code:

1)How substitute condition in a system of equations

2) How solve the obtained system ( not a linear system)

3) If its possible to plot the set of points (x_i,y_j, u_{ij})

Many thanks for your help

codetosee.mw

hi

how i can pdsolve these partial differentialequations?

thanks

10.mw
 

Download 10.mw