hi

I have metric tensor, how can i calculate covariant derivative of an arbitrary  contravariant tensor of rank 2?

Hy, 

I'm trying to display a list value in a maplet. But I can only manage to get textboxes, checkboxes and textfields. I know that in textfields I can display the evaluation of a function, but I tried many different ways and I still don't get the desired result. 

I designed a maplet with a button and 6 rows with a checkbox at the end of each row. When clicking the button I would like that the values of a list ("lstx", 6 values) are displayed in the 6 rows. Can you help me? thanx!!

I want to plot a graph of different values of k=0.1,k=0.5, k=-0.1, the display should be like this

my codes are 

restart:

V := exp(-x)*y^3/eta^3:

eta:=1+k*x+sin(2*Pi*x):

x:=0.1:

k:=0.1:

p2:=plot(V, y = 0 ..eta):

tf:=plottools:-transform((x,y)->[y,x]):

tf(p2):

plots:-display(tf(p2),labels=["v","y"]);

I wanna solve a collection of linear systems Ax=b_i, i=1..n, with A an upper triangle matrix, parallelly with Maple. Is there anyone can give me some suggestions? Thanks lot.

Error, invalid input: PolynomialIdeals:-Quotient expects its 1st argument, J, to be of type Or(PolynomialIdeals:-PolynomialIdeal, radalgfun, list(radalgfun), set(radalgfun)), but received Vector(3, {(1) = 0, (2) = y^2-x-y, (3) = 0})

restart;

with(Groebner):

IsNullZero := proc(tau)

if assigned(tau) then

        return tau

else

        return 0

would like to draw the pdf, however after tried two methods, still can not draw it,

how to draw?

l := [binomial(349,20), binomial(349,8),binomial(349,22),binomial(349,38),binomial(349,49),binomial(349,36),

binomial(349,59),binomial(349,41),binomial(349,32),binomial(349,21),binomial(349,23)];

sl := gfun[listtoseries](l, x, egf);

g := convert(sl, ratpoly);

g := g - subs(x=0, g); 

How do I use the letter I as a variable, not an imaginary number (the square root of -1) ?

i invent a method to make use of gfun 

as i know series are the number of ways 

however, after i input the number of balls in each box

calculate into binomial and input into gfun, and plot the graph, the problem is value too big 

cannot plot 

however, if using the count directly as input, the graph can be ploted, however, this is not

the logic of my understanding

if input series are not binomial, what are they?

would like to normalize it, how to find x such as 5.6 in this example

l := [20,8,22,38,49,36,59,41,32,21,23];

sl := gfun[listtoseries](l, x, egf);

g := convert(sl, ratpoly); 

g := g - subs(x=0, g);

g := g/subs(x=5.6, g); 

i am very bad at English so you ignore my mistake

i am beginning start use Maple therefore i don't know use Maple.

Like title, i have a circuit CLR with transer function H=

One of those vexing things that should be easy:

I am reading in a data file using ImportMatrix. Since the file has one column with texual data I cannot use datatype=float since that bombs. I >can< ImportMatrix with datatype=string or anything.

I then extract columns using the appropriate command and want to do something numeric with them (only with those columns that have correct floating point numbers). That fails since my data are now not floats (even when using anything...

i have an ode,which its derivatives are with respect to time,i want to use the output as a function of time to use it in a loop ,what should i do ?!

A:=a*diff(x(t),t,t)+b*diff(x(t),t)+c*x(t);

B:=solve(A,diff(x(t),t,t));

at first how can i define B as a function of t here?
how can i define initial conditons for this ?
for example :
a0:=diff(x(t),t,t) at time 0 (x(0)), but i do not know how to define this?

i also can not use B in a loop of time,t

Hi,
How do I complete the integral below? I'm not sure what the resulting function looks like, but it will be a function of n where epsilon is a real constant. My ultimate goal is to graph the resulting function where epsilon is equal to -0.4.

Thank you.

Hi, 

in my programm I've got a maplet with 6 CheckBoxes, but I can't manage to get the true/false-values in a list to use them. I think I should define a list, I tried:

BoxRow(...

   GridLayout([

      [CheckBox['CB1](), "Box1"],

      ....for all 6 boxes...

])),

lstW:=['CB1','CB2',...for all 6 boxes];

But all I get is: Error, `:=`unexpected.