Hello guys,i have some systems of diff eq,i tried to solve using dsolve but i have error.
system.pdf

system_solve.mw

When I was using Maple 2015, I can start Maple in Linux Mint Sarah, if Maple 2015 was installed in another Linux Distribution (that is, like Debian Jessie), as follows.   Suppose I have installed Maple 2015 in /home/programfiles/maple/maple2015, which is the location in Debian Jessie.  Start Linux Mint Sarah, then mount  the /home partition of Debian on the mountpoint /debian-home.  Now copy the file /debian-home/programfiles/maple/maple2015/bin/xmaple to be xmaple-a, and change the path in xmaple-a. Then copy the file  /debian-home/programfiles/maple/maple2015/bin/maple to be maple-a, and make some changes in maple-a. Then open a terminal, run the command  ./debian-home/programfiles/maple/maple2015/bin/xmaple-a. Thus I can start Maple2015 in Linux Mint Sarah, althought I have reinstalled Maple 2015 in Linux Mint.

But the problem occurs, when I upgrade to Maple 2016, together with Linux Mint from Sarah to Serena, because the method above does not work.  It gives information saying that the Host ID is wrong. But when I start Debian Jessie, I can start Maple 2016, and it works very well. So, what should I do to start Maple2016 in Linux Mint Serena, without installing Maple2016 in Mint, because I have installed in Debian?  

sols[11][1] = [1,1];

sols[11][2] = [1,2];

sols[11][3] = [5,10];

...etc

animate(plot, sols[11][A], A=1..20, frames = 20);

Error bad index into Vector

animate(plot, [sols[11]], A=1..20, frames = 20);

this writing can be ploted, but when i play animation, can not see it draw step by step

plot([[1,1],[10,20],[30,23],[12,30]]);

all lines are in the same color, but would like to specify the final line [30,23],[12,30] another color how to do?

plot3d([[1,3,5],[10,30,55],[50,70,25]]);

there is no lines in plot3d

plot can do this, plot3d seems different

plot([[1,1],[10,20],[5,7],[2,3]]);

Let L = {a1, a2, ..., an} (or L = [a1, a2, ..., an]) with is homogeneous polynomial. How to create function createDegree() return elements of degree <= n from L.

Expamle. L = {a-2b, b^2, (a+c)^2}.

createDegree(L,1) return {a - 2b}.

createDegree(L,2) return {b^2, (a - 2b)^2, (a+c)^2, a - 2b}.

createDegree(L,3) return {b^2, (a - 2b)^2, (a - 2b)^3, (a+c)^2, (a - 2b)b^2, (a - 2b)(a+c)^2, a - 2b}.

Thanks you very much.

Hello everyone!

Could somebody help me with reading data from Huge txt-file? My file contains matrix with 10 columns and 10^6 rows. Datatype is float[8].

I use "ImportMatrix" comand to obtain data from file, but it is rather slow ~ 33 sec.

is there an efficient way to read file directly using Maple? Or I should use C-dll to read file faster?

I want to calculate the ratio of the length of day and night for every latitude on earth ?
but i confused on using Maple in a wise way for finding the formula !
this is my demonstration :

shekofte000.mw
 

Download shekofte000.mw

As you see above, when I want to evaluate the definite integral, Maple can not provide the desired result. Why does this happen? How can I do so that Maple can calculate this integral?

Hello

Tryed to work this application, but problems encountered.

http://www.maplesoft.com/applications/view.aspx?SID=89020

and

http://www.mapleprimes.com/maplesoftblog/89021-The-Traveling-Salesmans-US-Roadtrip

I installed PostgreSQL, (i believe version 8.4 from 2010) which I found at "oldapps" (the current version is 9.6).

I'm running Win 7, 64 bit. Anyways, I have to change the paths below "Query the database":

driver := LoadDriver(classpath = "C://Program Files (x86)//PostgreSQL//pgJDBC//postgresql-8.4-701.jdbc4.jar");

conn := driver:-OpenConnection("jdbc:postgresql://localhost:5432/zip_codes", "postgres", "password");

I fail to see pgJDBC folder and a search for .jar files in the directory yields only 3 jar files, non resembling the above. tried example.jar

same error. heres a screenshot of my directory

Please i need help to plot the graph of f'' against episoln using the below BVP

HELP.mw

I want to plot the following equation

((1/2)*x*tan(log((1/5)*(2*(x^2+y^2)))) = y

I tried:

with(plots, implicitplot)

implicitplot((1/2)*x*tan(log((1/5)*(2*(x^2+y^2)))) = y, x = -5 .. 5, y =-5..5, numpoints = 1000, gridrefine = 6, color = red)

but result is strange... 

Hello, I have a function defined as

                                                   g :=  (x, y)->diff(u1(x, y), x, x)+diff(u2(x, y), x, y). 

I want to define another function as follows

                                                           f :=  (y) ->subs(x = 0, g(x, y)) ,

Now, when I want to calculate numerical values for the new function f(0), f(0.1), f(0.2),..... and so on. The following massage appear

Error, (in f) invalid input: diff received 0, which is not valid for its 2nd argument.

What is the problem here.

Amr
 

I'm curious to know if anyone has written a procedure to optimize the VRP with time windows / constraints.

I have a system of ode's

restart:with(plots):
eq1:=((diff(f(x),x$3)))+f(x)*diff(f(x),x$2)-a*diff(f(x),x$1)^2=0;
eq2:=(diff(g(x),x$2))+b*f(x)*diff(g(x),x$1)=0;
bc1:=f(0)=0,D(f)(0)=1,D(f)(5)=0,g(0)=0.5,g(5)=0;

dsolve can solve it easily.

sol:=dsolve(subs(a=0.5,b=0.5,{bc1,eq1,eq2}), numeric):

Now I was to use the numerical data from the sol in the following expression

Expr:=a*f(x)+b*g'(x)+c*f'(x)*g(x) # at x=1:

to make a table of this form a  b  c  Expr, where a, b, c vary simultaneously between 0 and 1 by 0.2 producing data for Expr.

Any suggestions?