Hi,

I'm trying to make a phase plane plot for the Lorenz system of differential equations around the equilibrium point (0,0,0) but when it keeps coming up with an error, saying it's "unable to obtain field plot, additional unknown(s) found: xy"

Any idea where I'm going wrong? Any help would be greatly appreciated!

Katie

sys1 := [diff(y(x), x) = a/(1-y(x))^b+c*exp(-d*x)/(1-y(x))^2]:

dsolve(sys1)

but the result is empty.

What can I do?

I am trying to get Maple to calculate this for me:

Let X₁,X₂,...X₈₁ be a random sample from a distsribution (not necessarily normal) with mean µ=49 and standard deviation σ =8. Let ¯X = (1/81)* ∑_i=1⁸¹ * X_i

_{I need to find the mean, the standard deviation and the approximate distribition of ‾X,}

_{BTW, the 81 goes directly...}

Hi,

I've been trying to manipulate the equations of a mechanism that I've exported from MapleSIM.  The system equations contain 4 differential ordinary equations, and 6 algebraic equations.  In MapleSIM it simulates fine, but I'm having problems simulating it in maple alone (without multibody exports).

I've tried solving the initial value problem by replacing all the time dependant variables with constants, (and as this is a dynamics problem) I supplied...

The operation: 2^29.403243784 gives me 7.0999999820*10^8.

However, using WolframAlpha, the answer is 7.10000000139658667836958142950829925944726171959 × 10^8.

These are 2 different answers. Can someone offer an explanation as to why this occurs and how I can avoid this problem?

Thanks in Advance!

Eddy Liu

I have this csv file on my website (the file is hosted on dropbox.com) that I want to load into Maple:
Hence I type:

URL := "https://dl.dropboxusercontent.com/s/7fqalrdtn0c3r8u/Stockholm%20Stock%20Exchange%28Percentage%20Change%29.csv?token_hash=AAGxpzva90O6oNlLAie3T1h0UNP06I5EPg2qrROHMglRMw&dl=1":
HTTP:-Get(URL, 'timeout' = 100)

Then I get:

Error, (in HTTP:-Get) timed out waiting for initial response from server

If you past the url into...

Here is a relation: t[n+1]:=((a*n^2+a*n+b)*t[n]+c*(n^2)*t[n-1])/(n+1)^2

t[-1]:=0 and t[0]:=1

a,b,c are integers and a,b,c are from 1 to 20 and n is from 0 to 20

the series t[n+1] is integer

I want to know how to list (a,b,c) that satisfies the above. Please help!

Why is there a difference between pdetest and algsubs for a PDE?
Shouldn't pdetest work the same as algsubs for the example below?

restart: with(PDEtools):

Eq:=u(x,t)*diff(u(x,t),t)=0:

tmp:=sin(w*(c*t-x))-(1/4)*epsilon*c^2*cos(w*(c*t+x))^2+epsilon*c^3*w*cos(w*(c*t-x))*sin(w*(c*t-x))*t+(1/4)*epsilon*c^2*cos(w*(c*t-x))^2+(1/8)*c^4*epsilon^2*sin(w*c*t+w*x)+(1/8)*c^4*epsilon^2*sin(w*c*t+w*x)+(1/24)*c^4*epsilon^2*sin(3*w*c*t+3*w*x):

sol:=u(x,t)=tmp:

I am attempting to apply some routine tests to determine the convergence of series with positive terms. I have run into a little difficulty with the root test. I am using surd( ) as shown below, but Maple will not give the exact value, which in my example, should be exp(6). Why is this happening and is there a way to get the root test to work?

Thanks!

I tried to use the parallelized Map function in Maple 16.

The following code worked as expected:

with(Threads);
Map(`^`,[1,2],2);

But then I tried:
Map(`op`,[[a,b]]);

and the Maple kernel crashed. This happens every time.

Any ideas what can be a reason of this?

I have a large sheet containing about three proc(). Four symbolic matrices of though small order but with complex values are being imported. There are also some other statements other than mentioned above. I have writing them in text mode.

What could be the possible reasons for connnection lost with maple though I have 4 GB of ram.

Thankyou!!!

Hi all,

I have 3 numerical methods s1, s2 and s3 for solving the linear system Ax=b ,

and I have the maple script (program) for each one of the methods. BUT I want to collect all of them in one program only such that the user(person) can select (choose) one of them,

How can I do this?

Thanks

Hi Guys. I´ve got a problem with the mod (mods,modp) function of maple.

I want to calculate the following congruences:

mod(4,-5) = -1 BUT maple returns 4

mod(-3,-4)=-3 but maple returns 1

and so on....

Does anybody of you know how to fix this? thanks!

Let say that you have two datasets:

restart:
with(MyFinance):
z1 := GetCSV("http://www.quandl.com/api/v1/datasets/USER_18Q/18R.csv?&auth_token=BXckVSG3twWkV272c9Q4&trim_start=1968-04-01&trim_end=2013-04-12&collapse=daily&transformation=rdiff&sort_order=desc");
z2 := GetCSV("http://www.quandl.com/api/v1/datasets/USER_18Q/1EV.csv?&auth_token=BXckVSG3twWkV272c9Q4&trim_start=1994-01-03&trim_end=2013-04-12&collapse=daily&...

When I solve a systems of equations, fsolve gives the solution

.

I now want want to define the variables x, y and z as respectively 5, 6 and 1 - but without copying the solution. Because this is a solution that I get in a loop, so it changes in every step. Maybe there is a easy way to put it in a vector?