I apologize if the forum is strictly for undergrad students.
I'm now on the section of Arfken's text "Mathematical Methods..." that deals with tensors, and I'm having a little trouble.
My problem is how to physically or intuitively, picture (for lack of a better word) tensors.
This also adds to the problem of not fully understanding and appreciating the difference between covariance and contravariance, other than it seeming to be arbitrarily subscripting or superscripting the tensor elements.
Thanks,
dc

How do I get the data from a 3d plot in maple 9 to a .txt or .dat file so I can plot it in origin or whatever?

When I click the "Save" or "Save as" options in my maple work, nothing happens, I can't save what so ever, does anyone else have this problem and if so, how do I fix it?

On page 121 of the 2007 edition of the Maple 11 Introductory Programming Guide in section 3.6 Exercises, problem 3, it says:
"... Find the inverse of (a*b)/c+((a-d)/(b*e))*I) in standard form, where a, b, c, d and e are real."
Here is my failed attempt:

View 4937_Problem_3.mw on MapleNet or

Download 4937_Problem_3.mwView file details
TIA

Hi, let's say i want the Integration Tutor show me how to integrate a function. Sometimes i don't know what the next step is, so i click the get-hint button. When it says "can you do a change of variables?" then i sometimes can't because i still have no idea. So i click "next step" and the result is shown. But i want to know what the substitution actually was, because it't not always obvious. But Maple doesn't tell me, for example, "t=2x has been applied" or similar.
What to do ?

Hello Maple friends,
I have a loop like this:
A := array(1..10);
for i from 1 to 10
do A[i]:= [ i, i^2, evalf(i^(1/3))];
end do;
print(A);
Nevertheless I dont know the following things:
1. How may I format in the way that in the third column of my array I see only 3 decimals?
2. As my matrix "A" is very big.. it is this the best way to avoid memory problems or there is some way to reduce this problem?
Thanks in advance for any help!
Jean

Hello Maple community!

As a part of a more complex (global) optimization problem I have a simple trigonometric parametrization of a classical probability distribution, i.e. just a list of positive number that sum up to 1. For test purposes, I take now one arbitrary element, p, of that probability list and use it as a target function for an optimization. Of course, one expects that one will find suitable parameter sets for minimizing/maximizing p. So here is my simple target function for the case of N=10 probabilities (requiring N-1=9 parameters):

objective := proc(x1, x2, x3, x4, x5, x6, x7, x8, x9)

I have found a very interesting physics problem which describes the motion of an airplane, it is a very simple math model.
We use only two coordinates, x(t) and y(t), t is the time.
The airplane starts at the point (0,a), a>0 and airport located at the origin (0,0).
It leads to the differential system ( v0, w>0 are given ):

sys_ode:=diff(x(t),t)=-v[0]*x(t)/sqrt(x(t)^2+y(t)^2), diff(y(t),t)=-v[0]*y(t)/sqrt(x(t)^2+y(t)^2)+w;
d v[0] x(t) d v[0] y(t)
--- x(t) = - --------------------, --- y(t) = - -------------------- + w
dt (1/2) dt (1/2)

I am currently working on a project that would involve students integrating a standard normal cumulative distribution function in Maple (essentially an erf function). This a simplified version of what we're attempting to integrate:
CDF(a*ln(x)+b)
from x=0..S. This should yield a closed-form solution like
S*CDF(stuff)-K*CDF(other stuff)
Of course, if one attempts to integrate the original CDF the integral will not evaluate. Is there a way around this, or will Maple simply fail to integrate erf(ln(x))?
Thanks,
Dan

Hi, I've been using maple10 worksheets under os x, setting the default zoom to 75%. This is fine. However, I've recently migrated to a linux system. Now, if I display a matrix under maple10 (or maple11) with 75% zoom, all of the spaces around the entries of the matrix are lost! This makes for unreadable 2d output. This is also true under 50% zoom (which is already unreadable) and if I change the default zoom in my .maple10rc file to _anything_ less than 100%, the same loss of spacing results. Does anyone else find this to be a problem. Sure, I can work with 100% zoom, but if there's a s

The first function I am trying to plot with maple is r(t)=3cos(2t)i-2sin(2t)j, and the second is r(t)=(t)^(1/2)i+(t^2-2t)j. If anyone can help me with the command lines that I must type to properly plot these function in maple I would be very grateful. :)

I am just starting to work with Maple 11, and having problems plotting two (single variable) functions in the same set of equations. I had **thought** that the way to do this was to plot a function, create a second expresssion in Math mode, and then simply drag the expression into the plot area. What happens is that the expression disappears, and nothing happens to the plot.
when I use plot**({expression1,expression2}) **, the plots appear just fine.
Are there any tips for me? I'm trying to write an "introduction to Maple" for beginning Calc I students, so I want to be able to give them the simplest instructions possible.

Hello,
I am using dsolve to solve a set of coupled differential equations. After they are solved I do some further manipulations on them. Every time I restart maple and execute the document, maple solves the equations but puts them in a different order and has the constants mixed up. Thus I have to keep hitting the (!!!) button until I happen to get the solution I had when I did the further manipulations. Is there a way to proscribe maple's output to a certain order? Here is an example:
One time the solution will look like:
{F(x) = f(x)*_C1 + g(x)*_C2, G(x) = m(x)*_C3 + v(x)*_C4}

I'm using the following bit of code:
step1:=1:for w[x] from start by jump to finish do:
fsolve(test2,k,complex):
answer:=%:
k1:=Re(answer[1]):
k2:=Im(answer[1]):
k3:=Re(answer[2]):
k4:=Im(answer[2]):
data[step1,1]:=w[x]:
data[step1,2]:=k1:
data[step1,3]:=k2:
data[step1,4]:=k3:
data[step1,5]:=k4:
step1:=step1+1:
end do:
Obtain All Data Points from Array
points1:=seq([data[d,2],data[d,1]],d=1..nopoints):
points2:=seq([data[d,3],data[d,1]],d=1..nopoints):
points3:=seq([data[d,4],data[d,1]],d=1..nopoints):
points4:=seq([data[d,5],data[d,1]],d=1..nopoints):
Obtain Relevant Data Points

It's me again, got another problem
i have another hyperbolic paraboloid equation
3*x^2-5*y^2=z
and it's conic sections at xy(z=0), xz(y=0), and yz(x=0) plane
3x^2-5y^2=0
3x^2-z=0
5y^2+z=0
but i have problems converting those conic equations into parametric equation, so it can be plotted using the spacecurve command
Can someone help??