I am attempting to define the rotation angle of an ellipse about the cartesian coord frame @ (0,0).  I am pretty sure the slope of the tangency vector @ both the major & semi-major axis is orthogonal to the vector originating from the origin from (0,0) with a length of a or b depending on which axis I am using.

My thought was in the case of the major axis that x = a*cos(theta) & the slope of the vector emanating from the origin is tan(theta).  So if I set dy/dx = -1/tan...

Hi, I am a student (with some programming background) in desperate need of help.

How can I create a zero based array in Maple and display it?

I am having all kinds of trouble creating vectors and arrays in Maple (the help is cryptic). This is the closest I got:

>F := Array(0 .. 4, 0 .. 4, [0])

That creates a 5x5 array of zeros, with the upper left element indexed by (0,0) (right?).

How do I display the array?

 Hi hi,

I've been sourcing various codes to help with plotting gaussian primes. I've managed a plot of gaussian primes within a given range with no problem at all. However, I'm looking now to make a plot of all gaussian primes connected by a step k or less to help communicate the Gaussian moat problem.  ( similar to figure 2 in http://mathdl.maa...

after do some correction still have error some later part....please give the commmen...

> restart;

> X:=<1,2,3,4,5,6,7,8,9,10>:

> Y:=<3.7,9.39,23.09,58.60,153.41,309.43,1103.63,2988.98,1112.08,22036.47>:

> eqn:=a*x+exp(b*x):

> solution:=Statistics:-Fit(eqn,X,Y,x,output=parametervalues);

 the problem is from maple.
It has to do with markowitz portfolio theory.
Ok Initially I have the risk and return from a given portfolio of 28 stocks.
I have defined both the return and the risk. Next I defined the covariance of the stocks also.
Next I defined some Lagrange multiplier where a and b are lambda1 and 2.
u:= j -> sum (x(i) s(i) s(j) - a - b f(i))
I then defined the next two Lagrange equations as
V:= sum(x(1)-1 = 0, i = 1 .. 28);

My problem is to find the right equation to get the best plot to the data shown below, please commen on it

> restart;

> with(CurveFitting):with(plots);

Warning, the name changecoords has been redefined

Warning, the previous binding of the name Interactive has been removed and it now has an assigned value

>

> datax:=...

I used the answer given in maple 10,  the error below happened, can you commen on it

restart;

> X:=<1,2,3,4,5,6,7,8,9,10>:

> Y:=3.7,9.39,23.09,58.60,153.41,309.43,1103.63,2988.98,1112.08,22036.47>:

Error, `:` unexpected

> eqn:=a*x+exp(b*x):

> solution:=Statistics:-fit(eqn,X,Y,x,output=parametervalues);

can any body help me?

i want to solve the following differential equation 

d²x(t)/dt² - 0.066405*sqrt((x(t))(2*r-x(t)))+0.00042105*dx(t)/dt



for this I ahve written the following program

restart

with(plots)

eq := diff(x(t), `$`(t, 2))-0.66405e-1*sqrt((x(t))(2*r-x(t)))+0.42105e-3*(diff(x(t), `$`(t, 1)))

pars := {r = 1}

eq := subs(pars, eq)

Hi,

Thanks a lot for your inputs and help to my previous post. Being novice, I learnt a lot from your inputs.

I am trying to solve a new nonlinear ode problem with the following boundary conditions bcs1 and bcs2 saperately:

a:= -1.24:

slope:= 1: # slope is varying with L

ode:= diff(y(x),x$2) –a*y(x) + y(x)^3 - y(x)^5  = 0

bcs1:= D(y)(0) = 0,   D(y)(L) = slope;

I am trying to create a certain visual effect in a Maple document / worksheet.

Basically, I have a small table with colored cells that I want to embed in a worksheet with an altogether different fill color. This sounds simple enough, but it appears that Maple's tables don't allow this.

I am trying to establish communication with a mySQL database from a maplet provided over the Internet.

It's my understanding that the classpath for the JDBC must reside on the same filesystem as the maplet.

When I test my maplet on any of my computers (all Windows) I have not problem. Because I know exactly where the JAR file is located the following LoadDriver command works:

  JDBC_MySQLdriver:=LoadDriver('driver'="com.mysql.jdbc.Driver",
    'classpath' = "C:\\Documents and Settings/Doug/Desktop/mysql-connector-java-5.1.13-bin.jar");

But, if I put this maplet on one of my websites for others to download, then this path will be meaningless for other users - and even if the path were somehow valid, there is no guarantee they have the right JAR file in this location.

If I serve the maplet with my MapleNet server, then I am (in principle) back in the first case. I can put the JAR file almost anywhere on the MapleNet server. A natural place seems to be in /root/maplenet/jar/. This would mean the following should work:

  JDBC_MySQLdriver:=LoadDriver('driver'="com.mysql.jdbc.Driver",
    'classpath' = "/root/maplenet/jar/mysql-connector-java-5.1.13-bin.jar");

Alas, this is not successful, complaining that the driver com.mysql.jdbc.Driver cannot be found. In case it matters, the MapleNet server is running under Linux and the other setups are different varieties of Windows.

Can anyone give me some pointers on how to make this work? In particular,

1. is it possible to allow users to use a remotely served JAR file?
   Maybe with a reference to the file given along the lines of
   'classpath'="http://maple.math.sc.edu:80/maplenet/jar/mysql-connector-java-5.1.13-bin.jar"
2. What is the correct syntax to specify the classpath on a Linux system that includes a MapleNet server?
3. Can I put the JAR file in the CLASSPATH environment variable on the MapleNet server (in /etc/profile)?

How do I change this equation with 28 variables

W:= 0.003000000000 x(1) + 0.004000000000 x(2) + 0.006000000000 x(3) - 0.006000000000 x(4) + 0.004000000000 x(5)   + 0.001000000000 x(6) + 0.001000000000 x(7)   + 0.004000000000 x(9) + 0.008000000000 x(10)   + 0.006000000000 x(11) + 0.01700000000 x(12)  + 0.002000000000 x(13) + 0.01300000000 x(14)   + 0.01200000000 x(15) + 0.006000000000 x(16)   + 0.001000000000 x(17...

I would like to compute the Lie algebra cohomology of a complex lie algebra g in a representation h/g where h is a Lie algebra containing g. is it possible?if yes, how. thank you.

Hi,

I used the dsolve command mentioned by Maple experts in the earlier blog to solve the following ode with bcs.

ode:= diff(y(x),x$2) + 1/x *diff(y(x),x) + 0.6*y(x) + y(x)^3 - y(x)^5  = 0

bcs:= D(y)(0) = 0,   y(d/2) = 0.8 * y(0)

The ode is a spherical coordinate system. The radius is defined by ‘x’ and the diameter by 'd'. 

The...

Hello!

I have a question about array/Array, as the picture illustrated, if applying a function to the entries of an array or Array, for example, map, then the results which maple yields lack of commas, as we can see, each entry in array/Array is so close and if the entries are very complex, then a confusion will be easily caused.

Is there any way to conquer it?