What's wrong?
Hello everyone.
I probe a Maplet's example about a Procedure Call but, when I run it, displays the following error:

I want to parse a large listlist with strings and floats

As an example
a:=[["he","45",123,76,"1.0",4],["know","4",9,34,"3.2",5]]

I want to parse a but it requires all entries to be strings

map2(map,parse,a) 
Error, invalid input: parse expects its 1st argument, st, to be of type string, but received 123

So my workaround was to convert all entries to a string.  How do I do that?  and how can I parse without having to...

question1:

plot(2/(3*x)+x, x = -5 .. 5)

Though this is ok ：plot(2/(3*x)+x, x = -5 .. 5, y = -5 .. 5)

but ... lazy to set range of y axis at the very start.

 question2：

how to plot more graph on different invertals  one time.

for example the intarvals [-5,5],[-1,1],[0,1]

Hi, I'm using Maple 13 off of my university's server. I was wondering how I can prevent "nested input", for lack of better words.

For example, say if define f := x -> something

Then I want another function to handle f's derivative: df := x ->diff(f(x),x)

Now I want to evaluate df at x=1 value so I do df(1)...

but I get an error:

Error, (in df) invalid input: diff received 1, which is not valid for its 2nd argument

I tried the following:

a:=1:

b:=2:

c:=-1:

L:=[a,b,c]:

M:=max(L);

However Maple outputs M:=2, but I want Maple to tell me the corresponding assignment 'b' of the maximum value of L, or at least 'L[2]'.

Is this possible and if so, how?

Thanks for answering.

Hi,

I am trying to figure out a way for Maple to handle group action.

Specifically, I have a set of sets. Each set is has three distinct numbers between 1 and 6.

Under a permutation element from S₆, this set should be mapped to another set.

For example [[1,6]] maps {1,3,4} to {3,4,6} (order is not important).

Anybody have a clever way to do this?

Regards.

I tried the following:

utility:=[CARA,CRRA,DARA]:

DARA1:=alpha+beta*x:

eval(utility[3]||1,[alpha=1,beta=2]);

Unfortnuately Mape ouputs: utility[3]||1

How can I get Maple to recognize the expression behind utility[3]||1?

Thanks for helping.

> restart;
> ode := `assuming`([(diff(r^2*(diff(`ϕ`(r), r)), r))/r^2 = k[0]^2*`ϕ`(r)+Q*Dirac(r)/`ε`[0]], [Q::positive, (`ε`[0])::positive, (k[0])::positive, r::real]);
> ics := `ϕ`(infinity) = 0, `ϕ`(-infinity) = 0;
> dsolve({ics, ode}, `ϕ`(r), method = fourier);
>

Download pintu.mpl.txt

I have an ODE...

Hello all,

I have a problem in comparing two expressions. I have to verify they are equal, but I am totally stuck even if it is obvious it is correct (but I have to do it with Maple).

These are the two expressions:

http://www.hostingpics.net/viewer.php?id=312636maple.png

I tried to convert them into exp, but it doesn't work at all...

Thanks a lot for your help, Julien

Hi, everyone, I am sorry that I have to post this question again since the last post sank and I did not give example at that time. In the example I post here, A[e,res1] and A[e,res2] are supposed to be the same theoretically. However, as I  used numeric solver (fsolve), they are 2 order different. Can anyone try the code and tell me what mistakes I made? I appreciate that.

> restart;
> with(PDEtools);
>
>
> # Electron velocity distribution:

Does anybody know how to make Maple 14 work with Visual Studio 10.0 Professional (not the express version)?  I can't seem to make this happen.  The problem has to do with the PostLink command.

I need to refer to all after "and" in the solution of inequalities system

Basically I want to plot the following parametric plane:

r (u,v) = [ u*cos(v) , u*sin(v) ]    where    u ranges from 1 to 2, and v ranges from 0 to 2*pi.

There are some things that has to be done.

- It has to be in 2 Dimensions.

- The axes has to be labelled x and y.

- The edge of the plan must not be rough.

- The entire plane has to have one color. No black stribes etc.

dear friends, I want to solve this integration with numeric methods. when i type it as nested integrals i reach the first answer, but when i want to use int(int), maple doesn't solve it(second answer). what's wrong with the input?

Hi,

On one axis (y vs x), I want to plot y=exp(1)~2.718 and x=4/(3*sqrt(exp(1)))~0.8087 so that they intersect to form a rectangle. Does anyone know how to proceed with this?

Any help is greatly appreciated.

Thanks