As I am beginner in maple, how to verify Bianchi Identities?

For Riemannian manifold,

1) R(X, Y)*Z+R(Y, Z)*X+R(Z, X)*Y = 0 

2) ((∇)[X]R)(Y,Z)W+((∇)[Y]R)(Z,X)W+((∇)[Z]R)(X,Y)W=0

I am not getting how to define vector fields. From my previous question I understood defining vector fields particularly. From that post I tried to verify the proof, but I cant. Please tell me about how to define vector fields without taking examples.

Thank in advance.

Hi, does anyone know how to plot a Bode diagram (phase and amplitude plot)? I am not looking for preparation of data but rather for the technicality of producing a plot that looks like I want, given I have data in the right form (which in my case are three Vectors: frequency, amplitude and phase).

Below is a rough sketch of what I am looking for. Note that the amplitude is on a log scale. It would be acceptable having to take the log of the data "by hand" to allow both vertical scales to be linear (I'd just convert the amplitudes to dB). The important things are the common frequency scale (horizontal) and the separation of amplitude and phase. I know plots has  dualaxisplot, and I know I can use plots:-transform to move a curve around, but I want the two axes on the left side, below each other, rather on the left and right. I'd like the frequency scale in the middle between the two curves, although I could settle on that scale to be below both curves.

I had some look around the Maple applications but did not find anything looking like this.

Thanks,

Mac Dude

I am very confused about function is():

1. is(a-b=0) assuming a::real,b::real,a^2=b^2,a>0,b>0;

2. is(a-b=0) assuming a::real,b::real,a^2=b^2,a>=0,b>=0;

the first command gives me false, and the second command gives me true...

any thoughts?

how to get maple to do linear algebra in Z_2 (integers modulo 2)

I don't want it to solve and then reduce mod 2 I want it to work over Z_2 so basis([ [1,1,1], [1,-1,1 ]) = [1,1,1]  etc

Hi,

a researcher at our department starts multiple Maple programs in parallel on our Linux servers.

Sometimes a high percentage of the resulting mserver processes hang. ps shows their state as

SNl (sleeping, multithreaded). strace to the processes shows that every one is waiting on a

futex without timeout. The problem occurs in versions 16 and 18. This is annoying.

Is there a fix for this?

Matthias Bauer

f := x^2*(y/x+sqrt(-7*y^2/x^2))/(y^2*(x/y+sqrt(-7*x^2/y^2)));
v := parametrization(f, x, y, t);

it can not parametrize.

i do not know which book teach group theory and algebraic curve

can we call this algebraic curve over finite field ?

how to represent a function as an algebraic curve equation for parametrization?

There is an heuristic-free algorithm, designed by Greg Reid to find structure constant of finite dimension Lie algebra of symmetries, admitted by differential equation. Details could be found in his paper:

http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=2316480

The main problem - I couldn't find implementation of it in Maple...

for i from 0 to 3 do print("rawData[", i, "] = new double[] { ", hello(i+1), ",", data[i+1], "};") end do

wrong format after copy to notepad from the maple 15

do not know why it insert a empty line, and make "};" in another line

and there is unexpected " 

wrong format example:

"rawData[", 0, "] = new double[] { ", 73.25, ",", 0.1510425143,

"};"
"rawData[", 1, "] = new double[] { ", 73.15, ",", 0.3974080269,

"};"
"rawData[", 2, "] = new double[] { ", 72.85, ",", 0.4661517269,

"};"
"rawData[", 3, "] = new double[] { ", 73.25, ",", 0.3974080269,

"};"

expected format:
rawData[0] = new double[] { 25.0, 20.0 };
rawData[1] = new double[] { 27.0, 34.0 };

Hello,

I have just updated maplesim to the last version (maplesim2015).

On the multibody examples of the maplesim2015 library, I didn't have any problems.

However, when i try to launch a simulation on a model i have made with a previous version (which worked before I use maplesim2015), i meet this problem :

May you help me to make the troubleshooting ? For the moment, I didn't manage to locate the error.

Do you have some ideas about this mistake ?

Thanks a lot for your help.

Hello,

i did see that u can calculate minimial polynomials for for example \sqrt(2) or smth.

Suppose now u have a ground field K and an extension L=K(p,q) where p,q are some given rational functions in the indeterminates x,y, now i would like to calculate the minimal polynomial for lets say x+y or x over L which then obviously splits over the field K(x,y).

Thx in advance

Hi .please help me for solve this nonlinear equations , that attch below

thanks a lots.....

dsys3 := {8*(diff(f2(x), x, x, x, x))+9*(diff(f2(x), x, x))+10*f2(x)+11*(diff(f1(x), x, x, x))+12*(diff(f1(x), x))+13*(diff(f3(x), x, x))+14*f3(x)+f3(x)*f3(x)+(diff(f3(x), x))*(diff(f3(x), x))+(diff(f3(x), x, x))*f3(x) = 0, 16*(diff(f3(x), x, x, x, x))+18*(diff(f3(x), x, x))+19*(diff(f3(x), x, x))+22*(diff(f1(x), x))+23*(diff(f1(x), x))+24*(diff(f2(x), x, x))+25*f2(x)+26*f2(x)+27*f3(x)+29*f3(x) = 0, 2*(diff(f1(x), x, x))+3*(diff(f2(x), x, x, x))+4*(diff(f2(x), x))+6*(diff(f3(x), x))+7*f1(x)+(diff(f3(x), x, x))*(diff(f3(x), x))+(diff(f3(x), x))*f3(x)+(diff(f3(x), x))*f3(x) = 0, f1(0) = 0, f1(1) = 0, f2(0) = 0, f2(1) = 0, f3(0) = 0, f3(1) = 0, ((D@@1)(f2))(0) = 0, ((D@@1)(f2))(1) = 0, ((D@@1)(f3))(0) = 0, ((D@@1)(f3))(1) = 0}; dsol5 := dsolve(dsys3, 'maxmesh' = 500, abserr = .1, numeric, range = 0 .. 1, output = listprocedure)12.mw

Hi everyone,

I have a great problem with the evaluation of following definite integral

> restart;

> int((t-x)^2)/(1+2t+(1/2)t^2-ln(t^2+2t+2)t-ln(t^2+2t+2)+arctan(1+t)t^2+2arctan(1+t)t+ln(2)t+ln(2)-(pi/4)t^2-(pi/2)t)^2,t=0..x)

I have tried different classical commands but Maple doesn't give an answer. Probably, it's just a silly fault.

Does anyone knows how to solve it?

Thanks.

Hi,

I'm using Java OpenMaple interface to call Maple functions from Java on Ubuntu Linux. I'm following the examples provided on Maple website. My Java code:

import com.maplesoft.openmaple.*;

import com.maplesoft.externalcall.MapleException;

class test {

    public static void main( String args[] ) throws Exception {

        String[] a = {"java"};

        Engine  t = new Engine( a, new EngineCallBacksDefault(), null, null );

        try {

            t.evaluate( "factor(-8*((16*I)*g**4*(-4*mc**2+u)**(-2)*(4*mb**2-u)**(-2)*u**(-1)*(12*mb**2-u)*(-4*s*mb**2+16*mb**4-4*u*mb**2+t*u-4*t*mb**2)*s*(4*s*mb**2+4*mc**2*s+16*mc**2*mb**2-s**2-4*t*mc**2+t**2-4*t*mb**2)*(12*mc**2-u)+(16*I)*(4*s*mb**2+4*mc**2*s+u**2-4*mc**2*u+16*mc**2*mb**2-4*u*mb**2-s**2)*(12*mc**2-t)*g**4*(t-4*mb**2)**(-2)*(4*mc**2-t)**(-2)*(-t+12*mb**2)*(-4*s*mb**2+16*mb**4-4*u*mb**2+t*u-4*t*mb**2)*s*t**(-1))**2);" );

        }

        catch ( MapleException e ) {

            System.out.println(e);

        }

    }

}

Maple throws exception:

com.maplesoft.externalcall.MapleException: Error, (in evala/Factors) input must be polynomials over the integers

The input polynoial is valid (when coping and pasting `factor(...)` directly into Maple interface, all works). When trying to factor simple polynomials like "x**2 - I*x" all goes fine too. Tried both Maple 17 and 18 (Linux).

PS. There is no problem when running this code on OS X (I tried Maple 16, 17, 18),  but I need to be able to run Maple with Java on my Linux cluster.

Hello everyone,

How can unknown values in boundary conditions of system ODEs be determine by using shooting technique. See the work sheet here Sht.mw

Thanks.