Let A and B be regions in space defined through f(x,y,z) > 0 and g(x,y,z) > 0, respectively.  How does one plot the surface of the object A ∩ B in Maple?

In Mathematica there is a command RegionPlot3D for that.  See sample here.  Perhaps there is an equivalent one in Maple that I don't know of.

This might be considered nit-picking, but nonetheless I think there is an issue: The metric tensor and its inverse are types (0,2) and (2,0) tensors, respectively. When once contracted with each other, the result is the Kronecker delta, which is then (necessarily) a tensor of type (1,1). I am therefore surprised to find that in Maple, this Kronecker delta is implemented as a type (0,2) tensor, via the command KroneckerDelta:

KroneckerDelta[mu,nu];

I don't think this makes any proper sense. I think that such an object of type (0,2) is, in fact, the metric itself. On a similar note, the (mixed tensor type) objects g_[mu,~nu] and g_[~mu,nu] are actually both Kronecker deltas, because they correspond to the metric having one index raised by contraction with the inverse metric itself. But, nonetheless, the following is the case:

g_[ mu,~nu],
g_[~mu, nu];

Relatedly, consider the following single contraction of the metric with its own inverse:

SumOverRepeatedIndices(g_[mu,nu]*g_[~nu,~sigma]);

Although this sum is formally quite correct, I think it should be given as just a Kronecker delta (of the correct mixed tensor type, that is).

How can I ask Maple to plot intersection of two implicitplot3d? It is explained how to draw the union in the Maple help by simply entering a list to combine plots, but I didn't see anything about intersection.

I probably worked too hard, but this result seems strange to me:

In a second example (not shown here, but in atttached file) all goes well. It is probably very simple, but at this moment I better go for a walk outside.

best regards,

Harry Garst

mapleprimes.mw

Sorry yes as the title suggests, id like to know how to execute keyboard and mouse pad actions in an automata of sorts.

I have a procedure that uses substitute. Below is my code

my_proc:=proc(func::`+`)
    ... #some calculatin

    subs([x[1] = 2, x[2] = 1], func);

end proc;
func:=5 + x[1]*x[2] + 10*x[1];
my_proc(func);

But when I call the procedure, her body is no substitution. What is the error? I can't understand what I did wrong?

In the help page for invlaplace we find the statement
"If the option opt is set to 'NO_INT', then the program will not resort to integration of the original problem if all other methods fail.  This will increase the speed at which the transform will run."

This statement is found in Maple 2017 and in Maple 8 and I believe in all versions in between.
Can anyone provide an example of a function F(s), where
invlaplace( F(s) ,s, t, NO_INT);
gives a different result (or works faster) than
invlaplace( F(s) ,s, t);
?
## It should be added that an identical statement is made in the help page for laplace itself.

I have alreday gotten the result and want to know how Maple was doing this calculation.

Would you like to tell me the way. Thanks.

eq12 := `assuming`([invlaplace(exp(-sqrt(s))*sqrt(s)/((sqrt(s)+a1)*sqrt(s+a2)*(s+a3)), s, t)], [a1 > 0, a2 > 0, a3 > 0])

Maple 2016 worked fine on July 27.

On July 28 Microsoft insisted on applying a patch to Windows 10 (they called it a "significant upgrade"). After that, Maple 2016 no longer works - it loads, presents the default worksheet, allows you to load a previous worksheet, but as soon as you go to do anything, it quits.

Any suggestions, other than downgrading to the previous version of Windows 10, which I have already done, (and turned off MS windows update services)?

How do you delete a row you added in a piecewise function. I was using 2D math input for the piecewise function and I decided not to have the third row at all. Deleting the content of the last row left a space but never removed the entire empty line. Executing it resulted in an error.

The manual only says how to add a row using CTRL + SHIFT + R, but not how to delete a row.

Any advise?

Converting a mathematical expression into postfix notation (also known as Reverse Polish Notation (RPN)) is a great way to speed up evaluation of arithmetic using a stack.

I was wondering if Maple has any inbuilt functionality to convert a string in infix notation to one in postfix notation? As a simple example:

(A + B * C) / (D + E * F)

Looks like this in RPN:

A B C * + D E F * + /

I cannot find anything with regards to Maple implementations of this. It would save me time to not have to write a RPN calculator in Maple if there is one already floating around somewhere. I would like to use Maple to output strings in RPN which can then be evaluated faster in another language.

-Yeti

the Initial value problem is well defined but i could not find solution of the problem. A number of method have been used but all are useless. How to obtained graph of the all equations. Also can we find the value of R (radius) where P is zero.coupled_IVP.mw

We know it's true that the Inverse Laplace Transform of two functions' multiplication is the convolution of every function's Inverse Laplace Transform. I think the case can be upgraded to multiple functions, i.e.

L^(-1)(f[1]*f[2]***f[n])=L^(-1)(f[1])∗L^(-1)(f[2])∗∗∗L^(-1)(f[n])

Does Maple have build-in function, which when given an expression that depends on x and y, will separate it to a product of two functions, one that depedns on x only and the other that depends on y only?

The input mathematical expression is known to be seperable.

For example, If the input is

((3*y + y^2)*3*x)/(x + sin(x))

Then I'd the Maple function to take the above and return list or set of two parts  {(3*y + y^2)   ,     3*x/(x + sin(x) } (if it can't separate it, it can return null).

The API can be something as  

 f,g = find_product_functions(expression,[x,y])

Something like this is used on determining for example if RHS of first order ODE is separable in order to solve it more easily.  collect() does not really work for this. So Maple allready does this internally in its ODE solver when it checks if ODE is separable or not. But is the function available for users?

How can I to build a Spinor with Physics package? I would like to explore a sigma model  from Lagrangian density. The ideia is search the Euler-Lagrange's equation and energy density of this model.