## How to obtain all solutions from dsolve?...

How does one obtain all solutions from dsolve? I see an option called Allsolutions, but this seems to only apply to solve and other functions. It does not work with dsolve.

For example, maple gives one solution for the following first order non-linear ODE. But the ODE has another solution y(x)=0 as well. How does one tell Maple to return all solutions? I am interested in this when using the 'implicit' option mainly. Here is an example

restart;
num:=-(exp(x)*sin(y(x))-2*y(x)*sin(x)):
den:=(exp(x)*cos(y(x))+2*cos(x)):
eq:=diff(y(x),x)=num/den;

r0:=dsolve(eq,y(x));

But when I tried y(x)=0, it turned out to also be a solution

odetest(y(x)=0,eq);
0

But dsolve did not return this solution on its own along with the first one.  But on another example, Maple did well, and returned all solutions. Here is the other example

eq:=(2*x*y(x)^2+2*y(x))+(2*x^2*y(x)+2*x)*diff(y(x),x);
dsolve(eq=0,y(x),'implicit');

In the above, Maple returned the two solutions.

Is there a correct way to tell Maple dsolve to return all solutions all the time? Why did it return both solution in the above example, but not in the first example?

I am maple newbie. Thank you.

## how draw by plot3D...

hi

how i can draw this equation in maple in 3D?

(x-y)^2+(x-z)^2+(z-x)^2=3

thanks

PLOT3D.mw

## How do I solve a simple line integral in Maple?...

Hello there. I have to solve a simple line integral (3*y-x)dL from A(2;1) to B(3;-1). A and B are points in the line described by function y=5-2x. I found a function LineInt. Using paramether Line I wrote LineInt(3*y-x, Line(<2, 1>, <3, -1>)), it doesn't work with error below:

Error, (in Line:-ModuleCopy) invalid input: invalid specification of line

It seems that the problem is with first argument, that is the equation under the integral sign. Or no... How to write it properly? Thanks.

## How to solve transcendental equation exactly?...

I mean the root of the equation

GAMMA(n-1/n)*GAMMA(1/n)/(n*GAMMA(n)) = 1

belonging to RealRange(Open(1),4). It should be noticed there are solutions outside this interval. Here is my try.

 (1)

 (2)

Also

 (3)

There is a substitute

 (4)

 (5)

There is a shade of hope that GAMMA(n-1/n)*GAMMA(1/n)/(n*GAMMA(n))  can be simplified.

PS. An SCR was submitted by me.

## Product simplification fails...

The following product

(product(mu^x[i]/factorial(x[i]), i = 1 .. n))

does not simplify to the most obvious form whatever I try

mu^(sum(x[i], i = 1 .. n))/(product(factorial(x[i]), i = 1 .. n))

What can it be?

## Iterator[CartesianProduct], option rank...

It seems to be a bug here:

restart;
with(Iterator):
M := CartesianProduct([1,2],[a,b],[c,d,e], rank=3):
n:=0:  for v in M do n:=n+1: print(n,v); end do:

1, [2   b   c]
2, [2   b   d]
Error, (in unknown) improper op or subscript selector

# for rank=9  ==>  [list, b, e]     ??

## time series troubles...

Dear Community,

I have two measured series - time series actually, stored in Excel:

• gas flow (ordered in ascending date order),
• pressure measurements (unordered, more or less randomly distributed dates),

I would like to:

• import the two series into Maple,
• convert them to time series,
• merge them in a way, that the unordered pressure dates are plugged into the ordered gas flow dates, so I finally get a single, ordered date sequence of ascending order.
• pressure and gas flow rates should remain separated of course, i.e. not merged (they should appear in two separate vectors, or matrix columns, whatever)
• if pressure dates and gas flow dates are the same, they should naturally be in the same row, i.e. belong to the same date.

No problems with the import, but I'm lost with the time series handling. I tried to figure it out from the help, but frankly the description is rather difficult, and I also haven't found appropriate examples. Is it possible to do it with Maple's time series feature at all, or something other is more practical? Files and my initial trial are attached.

best regards

Andras

Time_Series_Data.xlsx

TimeSeriesTest.mw

## maple 2016 JAVA crash....

Hello,

I'm stuck with maple 2016 as it crashes after a few minutes use.

it did work for a few weeks. It appears that its java crashing,

ive been given no error code or anything. uninstalling java and reinstaling did work.

im running the proper bit version. (64) rollio

tried backrolling windows, didnt work.

tried running it as Administrator no luck, ran it on backward compatibility windows 8 and 7.

ive run out of ideas the last option seems to be a clean windows install.

any help would be greatly appreciated.

the laptop in question (HP notebook 15-ba005no)

runs windows 10 (64bit)

8gigs of ram

cpu AMD E2-7110 1.8 GHz

128 GB SSD

dkdwarf.

## removing rows, or columns from a DataFrame...

Dear Community,

Is there an explicit command to remove rows or columns from a DataFrame? I've only found the Append command. What's the easiest way to do it?

best regards

Andras

## Finite Difference Method for PDE...

Dear all

I have a PDE and its analytical solution. I want to find the numerical solution by Finite Difference Method.

I duscratize the PDE and boundary condition and Could not able to solve them togethe.

Here is the file FEM-Nu.mw

## How to find the Taylor expansion...

of the implicit function sin(x+y)+sin(x) = y at x = Pi , y=0 of order 15? Here is one of the difficulties

restart; eval(implicitdiff(sin(x+y)+sin(x) = y, y, x\$15), [x = Pi, y = 0]);
Error, (in expand/bigprod) Maple was unable to allocate enough memory to complete this computation. Please see ?alloc

hi

thanks

dsove2.mw

 >
 >
 >
 (1)
 >
 >
 >
 >
 >
 >

## Asymptotics of certain subsets number...

Let us denote the cardinality of the subsets of {1,..,n} without two consequent numbers
(e.g. {..,4,5,..} is not allowed) by A[n]. What is the asymptotics of A[n] as n approaches infinity?
The same question for the case of three consequent numbers.
Here is my math experiment.
restart; L := combinat:-powerset({seq(i, i = 1 .. 11)}):#n = 11
nops(%);
2048
M := selectremove(c-> min([seq(c[k+1]-c[k], k = 1 .. nops(c)-1)]) = 1, L)[2]:
nops(M);
233
The other results are [11, 233], [15, 1597], [20, 17711], [21, 28657], [22, 46368].
These points are very close to some straight line in logarithmic scale as
plot([[11, 233], [15, 1597], [20, 17711], [21, 28657], [22, 46368]], axis[2] = [mode = log]);
shows. However, the ones do not exactly belong to a straight line:
evalf(ln(46368)-ln(28657), 15);
0.4812118247230
evalf(ln(28657)-ln(17711), 15);
0.48121182594077
eval(exp(.4812118247230*n), n = 15);
1364.000725  .
These results suggest that A[n] is asymptotically equal to exp(c*n) with c about 0.481.
I have not succeeded to find out the nature of the constant c.

question_on_asymptotics.mw

## logarithmic derivative...

Hello people in mapleprimes,

I want to ask you about how to make a function of function which makes a logarithmic derivative of a function.

For example, x^3 is mapped as h(x^3)=3h(x), h(x+y)=(x/(x+y))*h(x)+(y/(x+y))*h(y),

h(g(x)*k(x))=h(g(x))+h(k(x)).

I hope someone give me a hing to create h.

Best wishes.

taro

## Maple 2016 installation hangs on silent installati...

environment
- Windows 10 LTSB 64-bit
- Intel Haswell/Skylake

sequence:
1. install Windows unattended
2. install scheduletask for software installation (runs with systemaccount on windows starts and available network)
3. task runs a cmdfile(1) that map a networkshare and runs another cmdfile(2) on the networkshare
4. cmdfile(2) runs softwareinstallation one by one, every install is a seperate cmdfile
5. cmfile(maple.cmd) starts maple installation with the following cmdline
-->
START "Maple 2016" /WAIT "N:\Math\Maple\Maple2016Windowsx86Installer.exe" --mode unattended --desktopshortcut 0 --shortcutname "Maple 2016" --configureMatlab 0 --matlabpath "" --licenseType network --serverName "licserver.company.domain" --portnumber 27000
<--

Note: licenseserver and port are configured correctly, tested with manual installation of Maple

effects:
- installer starts and install some files (found unter C:\ProgramFiles\Maple 2016)
- installer persists in memory
- no startmenuentry for maple found
- no installler logfile in maple directory found
- install not finished

- try it with --optionfile ... -> hangs
- try copying all files to local harddisk and run it from there -> hangs
- try it running with a local administrator (using psexec) -> hangs

- if im logged in and run the installer cmdline manually with adminconsole or with systemaccount (psexec -i -s -d cmd) the installation runs perfect, but this is not what i need to install hundreds of machines

 First 26 27 28 29 30 31 32 Last Page 28 of 41
﻿