MaplePrimes Questions

Dear all,

I am looking at the help page for reading json files, but it is too advanced for me to understand...

Can anyone give an easy example where a json file is read into a variable and printing the data structure?

 

Hugs,
Louise =)

 

I can draw a triangle using the geomtry package:

point(A, 0, 0), point(B, 2, 1), point(C, 2, 0); triangle(T, [A, B, C])
d := draw(T, axes = none, color = black); t := textplot([[.227, 0.60e-1, typeset(theta)], [1.1, 0, typeset(k__2)]])
display(t,d)

The result is as below.

 

I would like to place the label k2 below the line but negative numbers do not work. I would like to put a label k1 to the right of
the opposite side but there is no room,  and finally I would like to put sqrt(k1^2+k2^2) above the hypotenuse slanted to be
parallel with the hypotenuse if possible.

  Hi, there

How can I draw the excircles, incircles,circumcircle and their centers of a triangle simultaneously with maple13 in a geometric plot? please specify the commands.

many thanks for your help

M.R.Yegan

Hi All

Assume that we have a stochastic model with following density function

and our goal is to estimate unknown parameters namely, alpha, beta, landa, mu and sigma by any available method especially maximum likelihood estimation method.
How can we do it with maple software?

Does the "MaximumLikelihoodEstimate" command can help?

or should i define Maximum Likelihood function first and then differentiate it according to unknown parameters?

 

thanks in advance

 

Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department


Suppose we have a function "f(x,y,z), "can we build a code such that for operator defined as

"Delta[]=((∂)^3)/(∂y ∂x^2)+((∂)^(2))/(∂y ∂x^)+((∂)^3)/(∂y ∂z^2)+((∂)^(2))/( ∂x^2)+((∂)^3)/(∂z ∂x^2)"

Such that

Delta*f(x, y, z)returns f[yxx]+f[yx]+f[yzz]+f[xx]+f[zxx]

where subscripts denote partial derivatives.


Download operator.mw

Regards

I defined a procedure, OrderB(0,b,c), that essentially determines the order of a group that is defined by 2 parameters (the first parameter is always zero), so the output is an integer and the procedure is defined for every integer value of both parameters. I wanted to structure the outputs into a matrix with columns that represent one parameter and rows that represent the other. However, whenever I try to apply a method of defining the matrix, Maple returns the values of the procedure and then gives me an empty matrix.

>f:=proc (i, j) -> OrderB(0, i, j+3);
>Matrix(3, f);
                               1
                               4
                               1
                               1
                               4
                               1
                               1
                               4
                               1
               [NULL,NULL...]


I tried a second method where I defined a set s such that:

s:={(0,0)=OrderB(0,0,0) , (0,1)=OrderB(0,0,1).....}

but upon execution, maple returns:

1
4
1
....
s:={(0,0)=( ), (0,1)=( )...}

Please Help. I don't know what I'm mising in the code that is keeping Maple from putting the outputs of my procedure into the matrix.

Been working on a diffy q project, new to maple here. Any help is appreciated. Keep getting a similar error.

 

"Error, (in dsolve/numeric/type_check) insufficient initial/boundary value information for procedure defined problem"

I thought I gave it initial values?

link to screenshot of the error bellow:

http://i.imgur.com/YVE1x7e.jpg

Hi,

For the paste several years, I have occasionally tested Maple on a simple integral,

simplify(int( exp(-I*k*x)/cosh(x), x=-infinity..infinity) assuming k,real);

The integral is returned unevaluated. There is no problems related to the complex exponential,

since also e.g.

simplify(int( cos(k*x)/cosh(x), x=0..infinity) assuming k,real);

and other variants are not evaluated.

Turning to the inbuilt fourier function (inttrans package) also does not work.

Evaluating laplace(1/cosh(x),x,s), and subsequently substituting s=I*k and s=-I*k and summing WORKS,

but gives (unnecessarily) an ugly result which it cannot simplify.

Finally, subtracting the (manually simplified) correct expression and simplifying gives 0 as

verification. I can not see any technical explanation for this bug.

Hi everybody,

how about a little arithmetical challenge?

 

known quantities : Z, t, epsilon : reals

let W = X+Y*t    X, Y integers, t real (t with unlimited precision)

let W = Z + epsilon (epsilon < 1/W), Z real (Z with unlimited precision)

W and Z have same decimal expansion ( W - Integerpart[W], Z - IntegerPart[Z] ), up to a certain "rank" (determined by the precision : epsilon)

Y*t and Z have same decimal expansion, up to a certain "rank".

The problem : build an algorithm to find the integer Y, using the "usable" decimal expansion of Z.

 

Thanks in advance for your contributions!

I am trying to find the root of an equation. The problem is, I keep getting the error

"Error, (in fsolve) Can't handle expressions with typed procedures"

and 

Warning, solutions may have been lost


whenever I try to solve it. Anyone have any ideas? My worksheet is here:  1.mw

Hello,

I have some points that i have plotted thanks to the function pointplot.

Is it possible to add tags next the points (like it is possible in Excel) ?

Of course, I have a vector with the definition of the contents of the tags that I would like to add.

 

Thanks a lot for your help

Hello,

I cant find solution how to create matrix form from equations of motion. Equations looks like this:

My equations ar much more complicated and one of them looks something like this:

 http://i63.tinypic.com/21c5ctk.png

and I want form like this:

I tried to do it using the Generate Matrix but it does not work as I expected. How can you get this form?

how to convert system of differential equations to differential form for evalDG?

 

[a(t)*(diff(c(t), t))+b(t), a(t)*(diff(b(t), t))+c(t)*(diff(b(t), t)), a(t)*(diff(c(t), t))+a(t)*(diff(b(t), t))+b(t)];

when i try eliminate dt which is the denominator

eliminate([a(t)*dc(t) + b(t)*dt,a(t)*db(t)+dt*c(t)*db(t),a(t)*dc(t)+a(t)*db(t)+b(t)*dt],dt);

[{dt = -a(t)/c(t)}, {a(t)*(c(t)*dc(t)-b(t)), a(t)*(db(t)*c(t)+c(t)*dc(t)-b(t))}]

 

i got two solutions, which one is correct?

a(t)*(c(t)*dc(t)-b(t)), a(t)*(db(t)*c(t)+c(t)*dc(t)-b(t))

does it mean that two have to use together to form a differential form?

 

update1

with(DifferentialGeometry):
DGsetup([a,b,c], M);
X := evalDG({a*(c*D_c-b), a*(D_b*c+c*D_c-b(t))});
Flow(X,t);
Flow(X, t, ode = true);

got error when run with above result

 

Hey all,

 

The title is probably very poorly explained and doesn't make much sense at all, but here goes nothing:

I define at the start of my .mw file that M:=1, but I need to be able to change it in order to run multiple different iterations.

So what I've come up with so far is a way to get a variable ammount of equations named "eqc(1,3,5,...)" The number of equations I get is equal to the M defined in the beggining. How would I go about solving this?
To give you an idea of something to work with:

So basically I'd need to solve as many of these eqc equations as I get. If I change M to, lets say 30, I'd need to solve 30 equations. This solve option above doesn't work and I've messed around with Vectors and Matrixes but I honesly have no idea what I'm doing there, so I thought best to seek out help.

 

Thanks in advance, Rafael.

How I can solve this:

 \lambda(x_0) = \lim_{n\rightarrow\infty} \frac{1}{n} \ln\left|\frac{df^n(x_0)}{dx}\right|
for different fn(x0) ? for f(x)=exp(x^2(a-x))



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