a:=["34mt5","tru532","64E22N"]

I thought this command worked on Lists.

Select(HasDigit,a)
    Error, (in StringTools:-Select) second argument must be a string

So then I thought maybe map might work

map(HasDigit,b)
     [true,true,true]

okay closer. 

Select(map(HasDigit, c), c)
     Error, (in StringTools:-Select) second argument must be a string

Can't figure out how to get around that string problem

I noticed that if I use add instead on using an integral int I dont get the same value. why ??

restart:
E := 7:   p := .5:
add(p^n*2^(n-1), n = 1 .. E)-p^E*add(2^(n-1), n = 1 .. E);
evalf(int(p^n*2^(n-1), n = 1 .. E)-p^E*(int(2^(n-1), n = 1 .. E)), 5);
 
                                  2.5078

Dear reader,

For a concept evaluation I need a system of 13 equations to be solved. Not necesserarily explicitliy, it would be sufficient for me just to see dependencies between variables. However either me or Maple or both are incapable of doing so. I am using Maple 13 by the way.

Hi, I'm having trouble getting Maple to solve the following simple inequality: H:=sqrt(1-0.3*sin(f)^2), solve(H>.9).  I get no solutions regarless of assumptions ect.  However, solve(H^2>0.9) works fine.  Anyone know whats going on?

thanks

okay, so I was asked this question

Hi,

Assume I have an eqn:=diff(x(t),t)+diff(y(t),t,t)+x(t)=0(It is just an example) for example, how can I find in which order variables are apearing here in this eqns?

for example I can give this eqn and result for x would be 1 and for y would be 2.

What is Maple command for that?

Thanks in advance,

Bye

 

 

I have two lists in Maple that I would like to join into a single list based on the values in a common field.  The best tool for such an operation is a relational database management system (RDBMS) where I would use SQL JOIN syntax.  The R program for statistics has an internal command, "merge" which can perform this operation on data frames [http://stat.ethz.ch/R-manual/R-patched/library/base/html/merge.html].  I would like an analogous operation in Maple as a convenient alternative to turning to a full RDBMS.  Does Maple offer such a command?

I have an application for wave temperature propagation in soil: with (plots); > u(x,t):=A*exp(-sqrt(w/(2*a^(2)))*x)*cos(-sqrt(w/(2*a^(2)))*x+w*t); > w:=10; > A:=4; > a:= 4*10^(-3); >plot3d(u(x, t), x = 0 .. 10, t = 0 .. 10); It is for x = 0. How can I do for x>0? Thanks, Raluca

I have an application for wave temperature propagation in soil: with (plots); > u(x,t):=A*exp(-sqrt(w/(2*a^(2)))*x)*cos(-sqrt(w/(2*a^(2)))*x+w*t); > w:=10; > A:=4; > a:= 4*10^(-3); >plot3d(u(x, t), x = 0 .. 10, t = 0 .. 10); It is for x = 0. How can I do for x>0? Thanks, Raluca

As part of a worksheet I have the following commands sys1sol := dsolve(sys1, numeric); sys1sol(2); Where the appropriate things have already been defined. As an ouput for sys1sol(2) I get [t = 2., i1(t) = 0.929532062300405666e-1, s1(t) = .907046793769959448] Is there any way I can extract the value for i1(t) and s1(t) in order to use them later on in the worksheet? Many thanks.

Hi !

Do you know how I can solve numerically a system of partial differential equation with Maple ? I've 3 variables : x,y,t and my system is :

EDP := [diff(s(x, y, t), t) = -.45*i(x, y, t)*s(x, y, t), diff(i(x, y, t), t) = .45*i(x, y, t)*s(x, y, t)-.2*i(x, y, t)-.7*(diff(i(x, y, t), x)+diff(i(x, y, t), y))]

f :=  1-g(x) ; g :=  piecewise(x = 20, .2, 0)
IBC := {s(0, y, t) = 1, s(x, y, 0) = f(x, y), i(x, y, 0) = g(x)}

 

Hello-

I've looked everywhere I can think of, but can't find the answer to this question: is it the case that the Ricci tensor in maple is defined as:

R_bca

as opposed to:

R_bac ?

These would differ by a sign.  Thanks!

a:=[["14","34",12.1","4.5"],["2","4","6","1.5"]]

how do I parse the data?  I came up with something but it seems quite bloated.

b:=map(a->[parse(a[1]),parse(a[2]),parse(a[3]),parse(a[4])],a)

Is there an easier way to parse the list without using map?  And if I use map, must I use the parse command on each position?

On 4th May I submitted Ploting 10 functions to plot mentioning codes with with Mapple.

 

I got some answers and have managed some additional ones.

 

Please help with items B, C and D

 

BR and thanks

mathstudentdk

Just something simple.  What's the easiest way to seaparate a list into a list of xy points?

I had come up with