Hello, 

      I am a student doing some self study over the summer trying to work through some of the John Taylor computer problems from his classcial mechanics book. Currently I hit a snag that most likely comes from the fact I am not well acquinted with Maple for solving IVP and DE's (we used Matlab in my DE class). I just need to know how I remove the following error:

Error, (in dsolve/numeric/SC/IVPsetup) initial conditions must be numeric

Here is a copy of my code:

R := 5;
5
g := 9.8;
9.8
deq1 := {diff(x(t), [`$`(t, 2)]) = -g*sin(x(t))/R, x(0) = 20};
/ d / d \ \
{ --- |--- x(t)| = -1.960000000 sin(x(t)), x(0) = 20 }
\ dt \ dt / /
dsol1 := dsolve(deq1, numeric);
Error, (in dsolve/numeric/SC/IVPsetup) initial conditions must be numeric

My hunch is that I need to set x'(0)=0 or something like I do not have enough intial values to solve the problem, but I could be wrong. Anyway anyone who can point out my mistake feel free to do so! Thank you!

hi.please help me for solve this integral

thanks aloterror.mw

(Phi)(x,theta,z,t):=-Phi[0].sin((m*Pi*(x-x[0]))/(L)).cos(n*theta)*cos((Pi.z)/(h)).sin(omega*t):n:=1:L:=2:m:=3:x[0]:=6:h:=1/(2);
print(`output redirected...`); # input placeholder
1
-
2
evalf(Int(diff(Phi(x, theta, z, t), theta, theta), z = -(1/2)*h .. (1/2)*h));
print(`output redirected...`); # input placeholder
/0.2500000000
| / / /3 \\
| |(Phi[0]) . |sin|- Pi (x - 6)|| . (cos(theta))
| \ \ \2 //
/-0.2500000000

\
cos(2 Pi z)| . (sin(omega t)) dz
/

In Maple TA in blackboard I am creating an assignment. Each week a part of the assignment will be posted. I was wondering if it is possible to have the same random variables in differnet assignmemts. That way the students can use their prior work. 

So in week one the students will get a set of random variables. But in week two a new assignment is posted were I want the same variables to come up for each student. Is this possible? (all students will have their own unique set of variables)

DEtools[DEplot](diff(x(t),t)=-abs(x(t)),x(t),t=0..40,[x(0)=1],numpoints=1000,dirgrid=[30,30],linecolor=blue)

i just need 1 at a11 position of a square matrix. do not need zeros like in complete pivoting. plz help

I want to plot curves with Japanese title and labels. I want to plot through an external java program. Is it possible?

When I tried, I am getting control character unexpected error.

Hi, Everyone.

I'm trying to figure out how to make a graph (actually a "line") change color based on certain criteria so I can create a Maple Application.

I've figured out the following, which indicates the sign of the graph by the color, but it's way more complicated than it ought to be.

It's also not robust as I need it to be, this happens to depend on the zeros occuring at integer values.  I could deal with that on a case by case basis, but not for something automatically.

I'm at a loss; maybe I'm not Googling the right things... maybe Maple can't do this (although I'd heard color tools were being added in Maple 16).

Does anyone have any suggestions?

Thanks In Advance!

Joseph

Am I right that using methods of the 1-forms (that implemented in liesymm or DESOLV), we can always generate determining equations for ODE, that solved for highest derrivative?

Hello, could someone please help me to understand this warning that i'm getting?

Warning, `N4ds` is implicitly declared local to procedure `SFunc`

Thanks

Maple is providing answers with the gamma function and LambertW function.  I am not a math major.  Although I did take advanced engineering mathematics in grad school, I am not familiar with transcendental functions.  

I did look at some of the help.  I tried to use the convert command to convert to elementary functions, however it did not help.  I looked at the definition for the Gamma function, GAMMA(z), and the upper incomplete Gamma function, GAMMA(a,z) that uses the generalized hypergeometric function 1F1.  Looking at the generalized hypergeometric function 1F1 defintion, hypergeom(n, d, z), it references the general pochhammer function, pochhammer(z, a), and product functions, product(f,k=m..n).  This all seems way too complicated.  

eqn1:= R = exp(t/MTBF) * (t/MTBF) * sum(1/(i!), i=0..n);

eqn2:= MTBF = solve(eqn1,MTBF);

Is there any easy way to convert to use basic functions like sum, int, etc.??

I am wanting to use the answer in Excel.  I have found some custom Excel VBA code that I could use to implement these non-standard function in Excel, but that seems like a lot of effort.

Lambert W function for Excel, work on real and complex number (VBForums)

Excel Add-Ins Incomplete Gamma Function (PC Review)

Update: Some more background on the problem is as follows. R is the expected reliability say 90%. MTBF is mean time between failures in hours. t is the time period of operation excluding allowable downtime. n is the allowed number of failures. I am looking to find the MTBF needed to achieve a certain required reliability, with the number of failures allowed, and the up-time operational period, being defined by the requirements as well.

To clarify the simplification does not necessarily have to be closed form, and an approximation would be acceptable. (in Excel I currently am using iteration over a number of rows, then using the Goal Seek tool to find the MTBF, however this is less than desirable to have to do everytime when looking at different trade studies) I am not that familiar with how to use assumptions in Maple, and do not know what would be the appropriate assumptions to make when simplifying. Thanks for your help.

Hi, I am learning GR and new to maple. I played with maple's DifferentialGeometry package.

While duplicated the maple GR example, in DGsetup([t, r, theta, phi], M1, verbose),

I got the error,

DGsetup([t, r, theta, phi], M1, verbose)

The following coordinates have been protected:
[t, r, theta, phi]

The following vector fields have been defined and protected:

Error, (in Typeset:-Tdisplay[true]) `alias` does not evaluate to a module

 I don't know how to fix it. Can anyone kindly help?

Thanks

I'm trying to build a Maple procedure that will generate vector fields on a metric with certain properties. Working with metric g over the coordinates {u,v,w}, call the field X = (a(u,v,w), b(u,v,w), c(u,v,w)). The field should satisfy <X, X> = 0 and have the directional covariant derivative of X in the direction of each coordinate vector field = 0 (with resepct to the Levi-Civita conenction).

Basically, these conditions yield a system of 3 PDEs and an algebraic expressionin terms of a,b,c. I've been trying to solve them using pdsolve, but I'm getting the error message:

>Error, (in pdsolve/sys) the input system cannot contain equations in the arbitrary parameters alone; found equation depending only on _F1(u,v,w): _F1(u,v,w)

I've attached my worksheet. Can anyone help me out?

Thanks! ppwaves.mw

Hello,

i am trying to get a latex output which equals the displayed maple equations, where i am using alias/surpress or declare to shorten the dependencies of my derivatives. Whereas in Maple this looks how i want it to look like, i can not get the latex() command to apply the aliases. Instead it replaces the short forms with the long terms before creating the latex code. Is there anyway to get a latex output directly from the displayed math WITH alias?

2 small examples:

Both yield  $ X \left( a,b,c \right)$ whereas i would like to get X. Simply substituing changes the partial differential symbol to "d" in the latex output and makes the equations unuseable, so this is no option i guess..

Thanks a lot for any suggestions!

I have the following integral equation to solve numerically:

v(x,t)=1 - h*\int_0^t JacobiTheta0(1/2x , \pi i s) v^4(1,t-s)ds

where h is a numerical parameter, and v(1,t) = 1-h*\int_0^t \theta_3(r)v^4(1,t-r)dr (theta3 is Jacobi theta3 function).

So I want to use an iteration method that will converge numerically to the solution, where v(1,0)=1.

How to use maple for this?

I want also to find the rate of convergence to the numerical solution.

 edit: I should note that v(x,0)=1, even though it's implied from v(x,t) above.