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)}

 

Im using maple 13

I always encounter an error everytime i use the feature ShowSolution

the error says:

"Error, (in Student:-Calculus1:-ShowSolution) input expression does not have any incomplete calculus operations"

This always happens in all the calculations.

 

How should I use the ShowSolution properly?

 

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 

How can I plot saddle path (trajectory) in dynamic system of two differential equations? I am trying to plot saddle path of Ramsey-Cass-Koopmans growth model in Maple 13, but I can't get the trajectory that goes to steady state. The system is following: > alpha := .5; theta := 1; rho := 0.5e-1; n := 0.1e-1; g := 0.2e-1; delta := 0.3e-1; > nulc := plot([((delta+rho+theta*g)/alpha)^(1/(alpha-1)), c, c = 0 .. 10], color = black, thickness = 2, labels = ["k", "c"]); nulk := plot(k(t)^alpha-(n+g+delta)*k(t), k = 0 .. 100, color = black, thickness = 2, labels = ["k", "c"]);

I want to use a color function with RGB-values in plot3d. Can somebody explain why

I want to draw the behavior of diff equation on xy-plane, where y=x'(t)

I get many xi(t), yi(t) on different consequtive intervals. I want to draw all graphs on one picture. (But I believe there is a decision that does not use the fact that the intervals are consequtive.)

Something like

"for i from 0 to 100 do

plot(xi(t), yi(t), t=i..i+1)

end do"

How can I draw multiple graphs on different intervals on one xy-plane?

Thanks!

My apologizes if I am posting it the wrong forum. I'm new to maple and I need help with the following question. I am able to produce the graph but I am not sure how to find the coordinates in order to do the follwoing steps. Any help with the following steps would also be appreciated.