I do the following:

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

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

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???

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

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})

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

It puzzles me that some of the choices for Clickable Math don't return a result. The image below shows four choices for clickable math. I would like it to "factor" exactly as shown in the upper left choice, but nothing happens after clicking the choice. (No matter how many times I try.) The choices "2D Plot" and "Isolate" return results ("Complete the square", in this case, also does not work).

My guess is that I'm asking it to operate on only the denominator of the rhs of the equation, but then why is the choice displayed at all. I've noticed this for some time in certain cases (like since version 17 was release).

Is there a way to make the choice return a result ? In this case, I don't find an equivalent command (factor, the denominator) using a right click. (In this case, I'll use another command "covert" "parfrac" . . .)

I want Clickable Math to make it easy.

Thanks. Cheers !

I typed (x-a)(x-a) into Maple 18 (the only thing in a new document) and got x(x-a)-a 

I'm wondering why it is evaulated like this?

Is this because of a setting?

BTW, I evaluated at a=4 first. 

I tried to find the root distritubion of a polynomial? 

When p=1, q=3, the following command works.

with(plots):

eq:=u^(2*q)+1-2*K*u^(q-p);

p:=1;   q:=3;

unitcircle:=implicitplot(x^2+y^2 = 1, x = -1 .. 1, y = -1 .. 1, scaling = constrained);

animate(complexplot,[[solve(eq, u)],style = point,symbolsize=10,color="red"],frames=50,K=-1..1,background=unitcircle, scaling=constrained, trace=20 );

However, when I tried p=2, q=3, only one root was shown on the animation.  

But   "complexplot([solve(eq,u)],style=point)"      showed  6 roots anyway.

I have no idea what was wrong. 

Download capacity_kfading.mw

Download capacity_kfading.mw

Download capacity_kfading.mw

Download capacity_kfading.mw

require help to overcome this warning. Thanks.

How do I mark a value on circles？

I want to plot Smith Chart and calculate the value Correspond to circles.

Any one can give me some suggestions or better idea to plot Smith Chart.

There are my code：Doc1.doc