Given the vector A = 4.00i^+7.00j^ , find the magnitude of the vector.

ithprime(n)  gives the unique prime whose index is n, thus ithprime(10) returns 29. Question: is there an inverse function in Maple, which given prime p would return n such that ithprime(n) = p?

Or if no such function exists can anyone suggest a way such a function could be coded?

Thanks in advance

David.

These are the timings for various algorithms, using different starting points deriving surfaces of dimension 5, 4, 3, 2, 1

times3:=[[], [.140], [1.344, .891], [1.578, 1.312, 1.375, 1.437, 1.922, 2.625, 6.406], [2.188, 2.312, 1.687, 2.110, 2.047, 1.578, 8.953, 1.891, 1.875, 9.344, 2.203, 55.969, 2.266, 2.531, 81.078, 2.172, 50.641, 2.500, 3.141, 61.656, 3.406, 3.375]]

times1:=[[.718], [.766, 4.703], [.750, .797, 7.594, 3.938], [6.594, 7.718, 11.969, 8.485, 11.391, 130.583, 548.284, 974.435], [7.281, 8.515, 65.569, 7.016, 8.312, 9.500, 8.562, 9.766, 10.641, 12.609, 13.281, 17.453, 18.640, 1763.860, 2659.990, 7812.89, 8189.139]]

So far i can get a boxplot of either:
Statistics:-BoxPlot(`~`[`~`[log10]](times3));
Statistics:-BoxPlot(`~`[`~`[log10]](times1));

but what I'd like is a boxplot like this but i can't work out how to do this.
 

A := (a^6)^(1/3)*(-b^3)^(1/3)/a^3

I Can't get this to simplify to -b/a. 

suppose i have afunction F(x) and i want to draw a sample for X from F(x)

Even and odd complement each other

how to find other sequence which complement each other?

such as 3 sequences divided integers or 5 sequences divided whole integers

is there monomials creation method such that solve result about coefficient and power are integers when right side columns are sequences?

i find even multiplication numbers are always solved into integers coefficient and power.

is there any more other sequences?

if I choose six multiplication table sequence, 

what is this complement of six multiplication table sequence?

AJUSTEMENTIMAGE.mwAJUSTEMENTIMAGE.mwHi,

How do to insert image in Plot0 ?

I am working on a simple program (4 lines excluding header/footer and debug command) that calculates a Lie-derivatives of a function G, supplied by the user, with the rule:
 

derivative of x[i]=F[i]  (an input supplied by the user),
derivative of y[i]=y[i+1].

this calculation revolves around a dot product, and I can't seem to work out what has gone wrong. My impression is that is because nops of a Vector gives you  1 more than the length of the Vector, so the Vector handed to DotProduct is wrong- but i can't see why it doesn't work in the case of G2 and F2 but does for G and F.

lieDer2_problems_mwe.mw

I am developing an algorythm which returns some differential equation, which I want to simplify. Here is an example:

eqq:= k[t]*(`ℓ`^2)*(diff(q[3](tau), tau, tau)+(5*alpha-sigma+2*theta+1)*q[3](tau)+(-4*alpha+sigma-theta)*q[2](tau)+q[1](tau)*alpha) = -(sqrt(m*(1/k[t]))*`ℓ`*k[t]*`Δθ`*(q[3](tau)-q[2](tau))*sin(sqrt(Lambda*k[t]*(1/m))*sqrt(m*(1/k[t]))*tau)+2*xi*sqrt(lambda*k[t]*m)*(diff(q[3](tau), tau)))*`ℓ`*(1/sqrt(m*(1/k[t])))

I want the parameters to be associated to the the variables, , ,  and their derivattives. So, I have used "collect" command, as below:

vars:= {q[1](tau),q[2](tau),q[3](tau),diff(q[1](tau),tau),diff(q[2](tau),tau),diff(q[3](tau),tau),diff(q[1](tau),tau$2),diff(q[2](tau),tau$2),diff(q[3](tau),tau$2)}:
collect(eqq,vars);

The problem is that the equations remain with non-simplified terms, such as the terms inside the "sine" functions and the term "k[t]*ell^2". The command "simplify" does not have any effect. Ideally, I would like to have something like this:

(diff(q[3](tau), tau, tau))+alpha*q[1](tau)+(-4*alpha+sigma-theta)*q[2](tau)+(5*alpha-sigma+2*theta+1)*q[3](tau)+2*xi*sqrt(lambda)/`ℓ`*(diff(q[3](tau), tau))-`Δθ`*sin(sqrt(Lambda)*tau)*q[2](tau)+`Δθ`*q[3](tau)*sin(sqrt(Lambda)*tau) = 0;

Does anyone know how to solve that?
 

Hi,

I am having trouble with the syntax for entering a limit of a multivariate function with direction specifiers.

For a single variate function f(x) the limit for x -> a from the right is specified by

limit(f(x),x=a,right)

A limit of a multivariate function f(x,y) for x -> a and y -> b can be entered by

limit(f(x,y),{x=a,y=b})

However I do not know how to specify directions in this case. Say, I want x to approach a from the right, and y to approach b from the left. What is the syntax to do this?

Cheers!

Hello

we have a matrix A (s.p.d) and b where LDL^t=A is the cholesky decompositon.

Why is the commands output

LUDecomposition(A, method = 'Cholesky', output = ['L', 'U']);

different from the output described in books or wikipedia.

To be exact:

L, the lower triangular matrix, is not normalized (the diagonal entries should be 1, they are not!)
L^t (upper triangular matrix) too.
D is not available for Cholesky at all.

If we calculate it with GaussianElimination

LUDecomposition(A, output = ['L', 'U'])

L is the wanted normalized lower triangular matrix, but its not normalized with cholesky.

And the DIAGONAL enntries are the wanted diagonal matrix D with cholesky.

This output is very confusing. Please can someone explain how to use/get the correct decomposition?

A example worksheet is attached.

Thank you :)!

Download dasfindetnichtmalpeterlustig.mw

dasfindetnichtmalpeterlustig.mw

How do i change keyboard shortcuts, E.g one of my keyboard keys are broken or have stopped working. How do i redirect my shortcut to another keyboard combination or another hotkey simply.

Hello, is it possible to have a document synchronized in the same way as Onenote? We're a group of engieneer students wanting to share documents, however the only way we can figure out a way to do it. Is uploading to maplecloud groups, sharing a "base" document, and everytime someone "updates" the document you save a new one. So it kind of defeats the purpose of making it a smart idea of collaborating on one document, am i missing something or is this really how oldschool it works?

Hello,

     I'm trying to simplify an expression involving signum and sqrt using assumptions:

assumptions := { A>0,psi::real,1+A*cos(psi)<sqrt(1+sin(psi)),1+sin(psi)>0 }:
signum(1+A*cos(psi)-sqrt(1+sin(psi))):
simplify(%) assuming op(assumptions);

It seems to me that, given these assumptions, we can safely conclude that the result should be -1. However, I can't get Maple to show this. Interestingly, setting A=1 does allow maple to simplify the result to -1. Is there something I'm missing?

Thanks!

I recently corresponded with maplesoft on whether the program Groebner:-Basis always produces reduced Groebner bases or not. They say it does. This mw appears to show it producing a non reduced Groebner Basis for a set of polynomials.

More specifically, the coefficient of the lead term of the first polynomial generated is not 1.

I'd like to be shown wrong here, but I am struggling to see what i could be doing wrong.