A := Matrix(3, 4, {(1, 1) = 1, (1, 2) = 0, (1, 3) = 0, (1, 4) = 0, (2, 1) = 2, (2, 2) = 2, (2, 3) = 0, (2, 4) = 0, (3, 1) = 0, (3, 2) = 6, (3, 3) = 4, (3, 4) = 0});
print(`output redirected...`); # input placeholder
Matrix(%id = 4436610626)
RowSpace(A);
print(`output redirected...`); # input placeholder
RowSpace(Matrix(%id = 4436610626))

 Why is this failing to give the row space? I copied and pasted it from the tutorial on this and it seems to run in the tutorial but not when I copy and paste it outside the tutorial? 

tutorial http://www.maplesoft.com/support/help/maple/view.aspx?path=LinearAlgebra%2FRowSpace

See picture

http://i.imgur.com/eQtEJU4.png?1

In general what is the best way to share maple code with users on this forum ? The above copy and paste looks messy. 

Hello,

A flate metal plate lies on an xy plane such that the temperature T at (x,y) is given by T=10(x^2+y^2)^2 , where T is in degrees and x and y are in centimeters.

Find the instantaneous rate of change of T with respect to distance at (1,2) in the direction of

a) the x-axis

b) the y-axis

I'm trying to solve this system of ODEs by Laplace transform. 

> de1 := d^2*y(t)/dt^2 = y(t)+3*x(t)

> de2 := d^2*x(t)/dt^2 = 4*y(t)-4*exp(t)

with initial conditions 

> ICs := y(0) = 2, (D(y))(0) = 3, x(0) = 1, (D(x))(0) = 2

Using 

> deqns := de1, de2

and

> var := y(t), x(t)

I need to solve it for both y(t) and x(t), I have tried this by:

> dsolve({ICs, deqns}, var, method = laplace)

And

> dsolve({ICs, deqns}, y(t), method = laplace)

> dsolve({ICs, deqns}, x(t), method = laplace)

However I get this error message:

Error, (in dsolve/process_input) invalid initial condition

Any help is appreciated

Hi Maple friends.

Maple tends to spit out results(which comprise of variables) in very complicated forms, and I have to use the context menu to select 'simplify' to reduce them.

Is there a setting which will automatically simplify Maple's output?

Thanks in advance.

test.mw

can someone please look at this modified C.Love code, hopefully the problem i'm having is self explanatary.

In Maple 15 is it possible to differentiate with respect to say x - y instead of x ? 

Thanks

Hi,

I have to run my model with lots of parameter sets and I want to export the result every time as a csv file.

Is therea possibilty to export the result automatically?

Thanks in advance for any help!

Hello,

I have a function, lets say g(x,y,...), that depends on many other functions. But I don´t want the results that are inside certain intervals, and I need to receive the results of those functions as something like NULL when asking for a result that is inside any of those intervals. That way, g(x,y,...) would also have to result in something like NULL if any of the lesser functions are NULL fora any given values.

I tryied using the piecewise command, and for the intervals that I wanted, it worked, but for those I wanted to be NULL, they were understood as 0, and so G(x,y,..) continued to exist but with a very different value.

To clarify what I need, I will try an exemple:

Imagine I have the function f(x)=x

I want to disconsider the results for x<2 and x>6, in a way that if I try the command 'f(1)', I will receive something like NULL and know that it is outside the range.

In the same way, I need the plot of this function f(X) to show the function only from 2 to 6, but not existing for the delimited intervals.

Ad if I continue and make g(x)=f(x)+10 , I don´t want g(x) to exist if f(x) doesn´t exist, and same for the g(x) plot, which shouldn´t be shown in the intervals where f(x) don´t exist.

Thank you very much for your atention!

Hello,

could you help me solve this error ? I don't understand what it means.

> eq3:=diff(x(t),t,t)+Gamma*diff(x(t),t)+omega[0]^2*(x(t)-(diff(x(t),t,t)+Gamma*diff(x(t),t)+omega[0]^2*x(t)+omega[0]^2*X[0])/omega[0]^2) = -omega[0]^2*X[0]:
> dsolve(eq3);
Warning, it is required that the numerator of the given ODE depends on the highest derivative. Returning NULL.

Thanks.

I remember to have seen and used a command to make the graph of the output of FeynmanDiagrams but I can not find more sample files. Someone can tell me how to do (plot a Feynman graph using the result of FeynmanDiagrams).

Thanks and sorry for my english.

Dear all,

I am trying to find the intial velocity of a ball that is shot under an angle while only the start and end coordinates are given. The air resistance should also be taken into account. 

In order to do that I have build the following Maple sheet:

Assignment_question_1.mw 

I have used two differential equations that both include the variables v0 and t, and then try to solve them. Only I receive an answer in the form of RootOf, which I cannot remove with for example allvalues. 

I have been working for quite a long time on this but I am not coming any further, so is there anyone who can find what I am doing wrong/what I should be doing else? Or maybe my whole approach is not right?

Even a small step in the right direction would be appreciated a lot!

Thanks in advance,

Elise

How do I permanently change the current directory on a MAC computer?

Kind regards

Per Kirkegaard

Hi all

The aim of following program is minimization but it is unable to produce it. where is the mistake?

Taylor2.mws

thanks a lot.

Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department

Not sure if this is the right place to ask this (if not, where is?)

Suppose I ask a question and get an aswer with a variable such as F=_X+5_X^2+7 and want to sort it so as to get 

5_X^2+_X+7

If I try sort(F,_X) it will read the underscore as starting a subscript... I can just highlight copy and paste an _X from the previous answer, but that is silly.

Hello,

I would like to know how to generate super/subscript characters in axis label. I have tried the double underscore (atomic variable style) and the super/subscript under "Format" in document mode but no luck at all. Any comment/suggestion is truly appreciated.

Yu-Hung Lien