Good day. 

I have been looking into the time series features in Maple and was eager to apply the models to one specific example containing 47 data points (attached).

When I run the ESM routine, Maple provides a forecast based on a (A,N,N) configuration. You will notice that the forecast for the following 12 data points is a constant value. I have also noticed this for several other data set examples and I would have expected the predictions to vary across the next 12 data points.

Does the (A,N,N) configuration in Maple automatically provide an optimal forecast and can anyone advise me on how to specify all possible combinations of (error, trend, season) models?

Thanks you for reading.

MaplePrimes_TS_Example.mw

solve((∂(-    ∇(f) ))/(∂ t)+((DotProduct(v[0],∇f))*(1-e(DotProduct(B,Omega)))+(c[s0]^(2)*rho[1])/(rho[0])(1-e(DotProduct(B,Omega)))+e(CrossProduct(∇ f,B))*Omega-e((DotProduct(-∇f,Omega))*(DotProduct(B,∇)))*(-∇f)+e(E)*(1-(DotProduct(B,Omega)))+e^(2)(DotProduct(E,B))*Omega-e*((CrossProduct(E,Omega))*(∇(-∇f)),rho[1]);

lis := SearchSmallGroups('order' = 10 .. 100, 'soluble'): 
seq(DrawSubgroupLattice(SmallGroup(g), 'highlight' = CompositionSeries(SmallGroup(g))), g in lis[10 .. 20])

I want to see if these red nodes are present in each layer and connected at each level, so I need to detect a large number of images. But if I put them in the same row, these images will be very small and I have to zoom in one by one with the mouse to see them. How can I set the size of these images?

ps：I'm currently using my eyes to determine if these red nodes are present at each layer and connected at each level, and I'd be happy if there was code to do this

I want to do some memory management in Maple for large arrays.

To clarify this question: What do I have to do in Maple to free memory allocated to an array? The indications I have are that memory probably is not freed, but rather a new variable of null is created that replaces the old one, but the old one is still sitting around.

Is this a bug?

I was cleaning my code using mint. It told me that

             These names were used as global names but were not declared:  right

which is the direction used in a limit. When this happens, I just replace the name with 'right' to make it happy. This works for everything so far. But now limit fails with

      Error, (in assuming) when calling 'limit'. Received: 'invalid directional argument'

the strange thing this happens only when adding assuming after the limit.

It seems to me to be some parsing issue?  Attached is worksheet showing the problem.

Maple 2022.2 on windows 10. So for now I will remove the '' and let mint just complain.

Download issue_with_limit_oct_31_2022.mw

Hi,

Since a couple of years ago,  SQLite has been enriched with a bunch of new math functions not existing in previous versions: acos, asin, atan, atn2, atan2, acosh, asinh, atanh, difference, degrees, radians, cos, sin, tan, cot, cosh, sinh, tanh, coth, exp, log, log10, power, sign, sqrt, square, ceil, floor, pi. 

Examples: In SQLite version 3.39.4 2022-09-29 15:55:41 we can invoke:

sqlite> select pi();
3.14159265358979

sqlite> select power(2, 3);
8.0

sqlite> select floor(2.35);
2.0

Package Database[SQLite] in Maple 2022.2 does not recognize these functions.

In oldest versions of Sqlite3 we were able to add these functions after loading an external extension with sqlite3 api function load_extension() (see  https://sqlite.org/contrib/download/extension-functions.c), but his option is blocked in Maple:

dbName := "d:/sq3_maple/etc.db":
sq3Extension := "d:/sq3_maple/extensions.sq3":

with(Database[SQLite]);
[Attach, Bind, ClearBindings, Close, ColumnCount, ColumnNames, 
  Execute, Fetch, FetchAll, FetchRow, Finalize, Open, Opened, 
  Prepare, RESULT_BUSY, RESULT_DONE, RESULT_ROW, Reset, Step]

conn := Open(dbName):
Execute(conn, sprintf("SELECT load_extension('%s')", sq3Extension));
Error, (in Database:-SQLite:-Execute) not authorized

Am I missing something? Any way to add these functions to SQLite in current version of Maple?

Thanks in advance.

César Lozada

PS: SQLite is updated in Mathematica 13.1

is a typical example of Maple output (in this case the natural frequency of a harmonic oscillator with m>0) where further simplification to text book notation is desired.

To get

the context menu did not help. On the command level, combine,radical (which I assumed is suitable) was also not effective.

Is there a better way to achieve the desired simplification than the one (found by trial and error) in the attachment?

If there is no better way: Would it make sense to improve the combine or any other command for such a case?

combining_radical.mw

How can these eight equations q[0]...q[7] be solved for the eight unknowns a1[0]...a1[7] and with the lowest CPU time

11.mw

Hello,

I use Maple and Maple Flow and want to work with physical units. However, I am quickly reaching the limits of what is possible. Now the question: Would it be possible to work with units and the piecewise function? In the attached example, the integration of a defined function is no longer possible. Or should I proceed differently in principle? Many thanks for any advice

Clemens

Download UnitProblem.mw

Hi, so I'm trying to solve this equation, but it seems that I've ran into two issues with it:

My problems with this this is such:

• The pi^2 did not get integrated into the solution, it's just a pi^2. I would rather it not be like that, but the actual resulting number from that division
• The units should result in Ω, but it's not, instead it just added the units from the original variables. How do I make it set to the "correct" unit?

LLC_converter.mw

Dear all

I construct by hand the two matrices L and U so that A= LU ( LU-factorization) 
I would like to find the number of arithmetic operations required to obtain the matrices 𝐿 and 𝑈

Number_arithmetic_operation.mw

Thank you

Hello, 

does the update of MapleSim 2022.2 have a bug when loading the own libraries? 
After installing the MapleSim 2022.2 update, my libraries have disappeared. I am unable to load them again. The libraries are still in the same folder as before, but when I try to load them, I get the error message

However, the library NoiseX is not listed in the left bar. Even when I try to create a new library, it is not shown in the left bar. On the other hand, there are no problems with the imported libraries. Many thanks in advance for any advice. 

Best wishes,

Clemens 

in some cases, when integral returns result with special function in it, I want to keep the integral as inert instead.

Currently I do an explicit check for some special functions that could show up (and add more if needed). like this

anti := timelimit(60,-int(B/A, x));
if  has(anti,hypergeom) 
               or has(anti,MeijerG) or has(anti,WhittakerM) 
               or has(anti,WhittakerW)or has(anti,EllipticE) or has(anti,EllipticF) then                            
   anti := -Int(B/A, x);
 fi;

It will be nice if I could write

anti := timelimit(60,-int(B/A, x));
if hastype(anti,'special_math_function') then                  
   anti := -Int(B/A, x);
fi;

Function advisor knows about all elementary functions in maple

FunctionAdvisor( elementary );
The 26 functions in the "elementary" class are:

 [arccos, arccosh, arccot, arccoth, arccsc, arccsch, arcsec, 

   arcsech, arcsin, arcsinh, arctan, arctanh, cos, cosh, cot, 

   coth, csc, csch, exp, ln, sec, sech, sin, sinh, tan, tanh]

Is there a way to make a type in Maple for "special math functions"?  You might ask, what is a special math function. Well, it is all build in math functions in Maple which are not elementary? So I do not have to list them all in name one by one as there are so many of them.

Any suggestions?

Maple 2022.2.

I have not used _Envsignum0 before. Been looking at it, and I am little confused.

My testcase is the following

restart;

_Envsignum0:=1;
fy:=1/2*(a^2/y^2+2*a*b/y-4*a*c/y+b^2-4*b*c+4*c^2+2*a)^(1/2);
limit(diff(y*fy,y),y = 0,right) assuming real;

It still has signum there., I assumed all are real.

Is there a setting that will automatically convert all signum to 1?  as _Envsignum0:=1; does not seem to do it. Or do I have to explicitly add positive each time? as in

restart;
_Envsignum0:=1;
fy:=1/2*(a^2/y^2+2*a*b/y-4*a*c/y+b^2-4*b*c+4*c^2+2*a)^(1/2);
limit(diff(y*fy,y),y = 0,right) assuming real,positive;

The problem with adding assuming real,positive is that it applies to all variables in the expression. I only wanted those that has signum on them, to be replaced by 1.

Maple 2022.2 windows 10

Dear All

Same calculation, but Maple gave 2 different results, when I used 2 different input methods, using palettes and through Maple Tutors, respectively (image). Can someone explain to me the reason?