I'm used to Mathcad, and I am very new to Maple. Something I cannot figure out right now is how to define multiple elments of a matrix using a function.

Input Data

Define system dimensions as n:=2;

i:=1..n;

j:=1..n;

lambda:=Matrix(n);

Lambda:=Matrix(n);

upsilon:=vector(n); 

Minor side note: I originaly had upsilon defined using the syntax "Vector[row](ncomp)", but this was giving me an 'exponentiation' operation error, so I changed it to what it is now (basically a list/array, which I guess has different type definitions that no longer cause the error?).

lambda[1,2]:=471.0433;

lambda[2,1]:=883.7530;

upsilon[1]:=58.69;

upsilon[2]:=18.07;

The Problem I'm Having

Now I just want to define Lambda using a function to define all elements (like I would in Mathcad).

Lambda[i,j]:= (upsilon[j]/upsilon[i]) * exp (-lambda[i,j]/2853);

which gives me an extremely long error message:

Error, invalid input: exp expects its 1st argument, x, to be of type algebraic, but received Matrix(2, 2, {(1, 1) = -0.3504976272e-3, (1, 2) = -.16509955895845776, (2, 1) = -.30975332953088164, (2, 2) = -0.3504976272e-3}, datatype = float[8]

As far as I can tell (keep in mind that this is my very first Maple project) that it doesn't like lambda as a matrix? But shouldn't it just evaluate to the element? and why is (2,2) and (1,1) giving values, because it should intialize to zero, so exp(0) = 1 in these cases??

I tried to simplify further by just trying

Lambda[i,j]:=(upsilon[j]/upsilon[i]);

but then it just gives me 1, and when I look into Lambda all the elements are now 1 when only the diagnol elements should be 1 (the rest some fractional amount)??

I am at a complete loss. I thought about doing something like For i = 1 to n etc. but then it just looks like coding, which defeats the purpose of trying to make a calculation sheet documenting the procedure...

Any help and/or insights into what I am doing wrong here would be most welcomed :)

P.S. I've just noticed that there is an upload option :/ Wilson_Equation.mw.

I do the following:

restart; 
z := x + y; 
type(z, specfunc(name, `+`));

However the result is 'false'. How to correct my type checking?

Download pattern.mw

This probably isnt too difficult to write a procedure to generate the expression, given C=2,3,4,5,...

But I may be thinking too much and stuck...

Also, I am thinking that if it is possible to use something like a "fibonacci sequence", in the famouse example here, which uses the option remember; in a procedure. Probably, we dont need to use this.

Thanks,

casper

I have been learning to use the Physics package in Maple 18.  I just updated to the latest version of the Physics package to see if it would fix the problem by my results are the same.

When I take a covariant derivative in spherical coordinates it does not appear to have a scale factor such as g_kk below.  

This definition of comes from the Mathworld web site.  I think they have a typo such that it should actually read h_k which is the scale factor instead of g_kk which is the metric.  They are related by h_k^2 = g_kk.

Why doesn't Maple's covariant derivative have the scale factor when I am differentiating in spherical coordinates?

Thanks!

 While calculating an integral including complex numbers, I have encountered with the output "undefined if a+ib>0". What does this mean?A complex number bigger than zero???

restart:

Eq1:=(-1/k)*B*(diff(-f(r),r$3)-(1/(r+k)^2)*diff(f(r),r$1)+(1/(r+k))*diff(f(r),r$2)+(1/(r+k)^2))

-((r+k)/k)*B*(diff(-f(r),r$4)+(2/(r+k)^3)*diff(f(r),r$1)-(2/(r+k)^2)*diff(f(r),r$2)+(1/(r+k)^2)*diff(f(r),r$3)

-(2/(r+k)^3));

bcs:=f(-h)=1/2,(D@@1)(f)(-h)=1,f(h)=-1/2,(D@@1)(f)(h)=1;

dsolve({Eq1,bcs},f(r));

Please have a look.

Thanks

One of my students just showed me the following strange behaviour with Maple 18 (17?) on her Mac computer:

After entering anything at all in math mode, the Enter key has no effect.

After an empty line in math mode the Enter key works fine, and also after anything (including nothing) in text mode.

She has uninstalled and reinstalled Maple several times.

I have absolutely no clue. Do you?

If nobody has a clue, I will be back with more detailed information.

Knud Fjeldsted
Denmark

Hello those who are in mapleprimes,

I want to devide both hand side of inequality by positive a.

And, the ways I want to know are two ways for doing this.

1)         c:=a<b: c/d assuming d>0;

returns 

I don't know why the result isn't a/d<b/d.

2)        the second way is one to focus on op(0,c) being <. And, from lhs(c), rhs(c), and op(0,c), 

I want to constract lhs(c)/d op(0,c) rhs(c)/d, that is lhs(c)/d<rhs(c)/d.

Please tell me about this.

Thank you in advance.

taro

Hi,

I am having trouble solving the PDE. Can anyone shine some light?

Download 1234.mw

cubic4.mw

I have created a multivariate polynomial with variables P1,...,P6, and would like to factor the poly in terms of (Px-Py) where x,y are combinations of 1-6 (x not equal y). I am new to Maple and have only tried the "Factor" and "Simplify" dropdown menu commands, but neither of these seem to produce anything remotely close to what I need.

Thanks

Derek

I would like to attach a maple document to refer to but dont see how to attach a document to this question.

Edit:

Having Uploaded the intended file, I can direct your attention to eqn (14) which is factored into (15) nicely, but when things get a little more complicated as in (45), the factored form in (46) does not contain any of the (Px-Py) forms I am looking for. Is there a way to steer the factor function toward certain forms?

Edit2:

divide.mw

As seen in this form of the problem statement (using quadratics instead of cubics), the divide function does not seem to capture the factorability. From file divide.mw (attached), eqns (19) and (24) are equivalent since the subtraction of the two produces 0 as seen in (28), however both the factor command (23) and the divide command (29) produce nothing substantive.

How do I make a timer to record the seconds elapsed between button clicks?

I would like to make a multiplication game for primary students and want to have it return a score that reflects how long it took to answer the question.  I've been through the help pages (i.e. the lunar lander module) so I know it can be done but I am a Maple novice and am having trouble replicating it.

Thanks for your help!

Hi, those who are in mapleprimes.

i have a problem in solving inequality with symbolic notated parameters.

I wrote the following code to solve for n(SPH), but couldn't obtain any result but an error message.

solve(-s*(-n(SPF)*tau+n(SPH))/(tau-1) <= n(SPH),n(SPH)) assuming (tau<1,s>0,s<1,tau>0);

The error was

Error, (in assuming) when calling 'unknown'. Received: 'invalid input: Utilities:-SetSolutions expects its 2nd argument, solutions, to be of type ({list, set})({piecewise, ({list, set})({name, relation})}), but received [s = -tau~+1, [SPF = SPF, s = s, tau~ <= 0]]'

Please tell me how I should do to solve the inequality.

Thanks in advance.

taro

i := I;

assume(a>0);

assume(b>0);

assume(r>0);

assume(k>0);

assume(w>0);

Hz := k*(z^2-2*r*a+r^2)/((z-1)*(z^2-2*b*z+1));

Hzw := eval(Hz, z = exp(i*w)); assume(a > 0);

Habs := simplify(abs(Hzw)^2);

p1 := eval(Habs, w = Pi) = (10^((-3.3018)*(1/20)))^2;

p2 := eval(Habs, w = (1/2)*Pi) = (10^((-.1758)*(1/20)))^2;

p3 := eval(Habs, w = (1/4)*Pi) = (10^(6.425*(1/20)))^2;

p4 := eval(Habs, w = (1/8)*Pi) = (10^(54.5699*(1/20)))^2;

solve({p1, p2, p3, p4})

eq1 := fracdiff(u0(x), x, 0.5)= 0 with initial u0(0)=0

and i need the value of  u0(x) to find u1(x) from

eq2 := fracdiff(u1(x), x, 0.5)+f = 0   for some function f

thank you

Say the values of i^2 are being calculated from within a procedure,

mytest:=proc(n)

local ans;

    ans:=0;

    for i from 1 to n do

   ans:=ans+i^2;

   end do;

   return ans;

end proc;

Could I have a (time series) plot of i^2, while the values are being calculated?

The above is a toy example. What I want to archieve is to track a particular intermidiate values while the procedure is running.

Thanks,

casper