I am getting different results when determining the eigenvectors of a simple beam vibration problem in 2 ways :

See attachment :
1) When generating a matrix with GenerateMatrix([eqs..],[A,B...]) , or with
2) reformulating the same matrix by hand with S:=Matrix(4,4,[[ ]]) I get different eigenvectors for actually the same matrices ?

Tried already commands like 'convert' , 'Normalize', setting precision, to no avail.
Is this due to rounding ?

Any suggestions ?

Thanks ! 

Eigenvectors_2.mw

The link to the .mw file is underneath the content.

I was trying to solve the first order ode for x(t). pp1 and pp2 are essentially diff(x(t),t).

I just wanted to see them plottet. While deriving these equations (which stem from a first order nonlinear quadratic diff. eq.) I had to distinguish between those 2 solutions. Also I made the assumption that diff(x(t),t) everywhere so the only solution being allowed should be pp1. Oddly the analytic solution for pp2 looks like the numeric solution for pp1 and my question is: Why is that?

Download rutschender_Stab.mwrutschender_Stab.mw

Hi there,

How can I plot the equation $r=1/theta$ in polar plot in maple13? and in general for plotting $r=1/(theta-alpha)$ alpha is constant.?

 Any help will be appreciated.

Regards

Yegan

Hi

equation:

X=1/(a)*[2/(mc0^(m-2)]^(1/2)*(c/c0)^(1-m)*[(c/c0)^m-1]^(1/2)*F(1,1-1/m;3/2;1-(c/c0)^(-m))

for:

c0=0,0.277164,0.340257,0.408617,0.581345,0.649268 and a^2=2

and   m=0,1/2,1/3,3/4,2,3

if 0<x<1 and 0<C(x)<1

and F is hypergeometric function

plot C(x) vs. x

I tried to run a few calculation on maple, the numerical output is, e.g.

0.3 10^(-5)

Is there any simple way to set it as 0.3e-5? I am not intened to write the data into a file, hence, i am not sure if writedata is a suitable option.

Thank you very much! 

Hello people in Mapleprimes,

I want to do calculations about an expected value.

For example,

expectedvalueofc.pdf

that is, \int_a^b c d \Omega

where, \Omega is a distribution function of c. 

But, I don't know whether this equation can be put into worksheet.

Is there no way other than writing this as 

\int_a^b c g(c) dc, 

where g shows a probability density function.

Can I use Statistics[ExpectedValue] to calculate expected value with a general distribution function, not specified 

to normal distribution?

I hope you will give me some hints.

Best wishes.

So as the title claims I am new to maple and am having trouble with trying to learn how exactly to accomplish certain things.

Mainly being that I am having trouble with a set of exquations that are equal to zero which I then set equal to eachother in order to solve for the values of the variables (x,y)

for example lets say that

f1:= x³-x²-(y²-y)x = 0

f2:= -1-ln(y)+ln(x-y) = 0 

now from here I start to become a bit iffy on what exactly I am supposed to be doing. I have a line of code stating 

f3:=f1=f2

and from there I have had absolutely no luck what so ever. 

any help would be much appreciated.

Hello!

I wanna ask you the next question.

I have system of four linear differential equations and solution of it (four functions f1,f2,f3,f4). When I try to verify my solution by odetest() I get a set of values: 0 and two bulky expressions with imaginary units.

So, I can't understand exactly my solution is right or not?

sysODE:={bla bla bla}{f1,f2,f3,f4}(x);
solsysODE:={f1(x)=........,f2(x)=......,f3(x)=......,f4(x)=.......};
misalign:=odetest(solsysODE,sysODE);
nops(%)
3
op(1,misalign) # zero
op(2,misalign) # not zero
op(3,misalign) # not zero

Thank you!

For simplicity in a long calculation I substituted sum(w[k],k=1..n) by the expression Sw using algsubs. At the end of the calculation I want to replace back Sw by the original expression. Thanks

Hi all!

I have this function:

Problem is it doesn`t have any output, really anoying! Could you please help. Thanks guys!

I need to find only the x for which a^x = b mod p is a solution of.

Dear friends!

My question does not concern essential functioning of Maple and does not influence on any computation performance. But I ask you to pay attantion to it.

For a long time ago I noticed, that representation of some elements of Maple worksheets does not correspond to settings. For example, I would like to have 2D Ouput style in bold font, which I used in Classic interface in the years of my youth. I adjusted this style as needed:

Nevertheless, output font has a normal (no-bold) style:

Is it possible to fix the problem?

I want to solve a system of 11^3 equations  (each equation is quite small) in 11^2 unknows. The equations are all viewed mod 2. I only want to know the possible solutions for 11 of those variables.

That is given variables a[i], 1 from 1 to 11 and b[n] for the remaining 11^2-11  variables.

I want to know all the  distinct consistent solutions for the a[i]'s. I dont care what the b's are as long as the solution to the a[i]s is consistent.

I am VERY sure that the equations will quickly show that there are no solutions but I am having difficulty comming up with how to code this. 

The expression

A := (a/u*(y*exp(-y) - x*exp(-x))/(y-x) + b/u) / (c/u + d/u);

is obviously equivalent to

I typed the latter by hand since I don't know how to do it in Maple.  Is there a trick to get Maple to do the simplification as shown?

Another worksheet dilemma  I am having with Maple.

I have number of "execution groups", like this, I created using CTRL-J

Now I wanted to put these in a section, so it becomes like this: (I had to make new worksheet now)

Since I did not know how put existing groups inside a new section I wanted to create (the section always comes at different level that does not include the groups), I thought I can create the section first, then go copy the groups and paste them to the new section.

The problem is how does one actually select multiple execution groups for the purpose of copying them?  The obvious way is to use the mouse, and select all groups with the mouse.

Well, this a big problem, since my groups are so large, I can spend 5-10 minutes scrolling down, very slowly to select them. my hand gets tired and I get tired doing this. I also one time got an error from Maple, saying selection too large, and something about rtf memory error or something. This is after wasting 10 minutes scrolling down carefully to select over 10,000 lines that is one large list.

In Mathematica, I can simply select a cell, no matter how large (an execution group in Maple talk) by just clicking on the edge of the cell.  I can select multiple cells the same way (hold, click on the edge of all). Very easy. I do not have to scroll down to select the content as I do with Maple

But here, with Maple, I put the mouse of the left edge, and can't select the group. Nothing happens. So I have to actually scroll down. I do not see the point of having a left [ edge to a group if one can't use it to select the group?

So my question is: How to select one or more execution groups without scrolling the mouse over all the content?

I had to use integration by parts to get the answer I need, but I do not think it is really needed for this. compare the output from:

r:=int(tan(x)^(n-2)*sec(x)^2,x);

(which is pages of very complicated output), with this:

r:=Int(tan(x)^(n-2)*sec(x)^2,x):
simplify(value(IntegrationTools:-Parts(r,tan(x))));

Does one really have to tell Maple to do integration by parts for this? I would have expected int() to do it as is.

Please compare to Mathematica:

Maple 18.02

added

The reason I think this should have been done by int() directly is that it is direct  application of the power rule of integration. I can't write Latex here, so I wrote it on my computer, and I copy the screen shot to explain for those interested:

Maple is so good in differential equations, but does not seem to be as good as it should when it comes to integration.