L = Import[
  "C:/Users/asus/Desktop/op21new.g6"]; # Change this line
t = AbsoluteTiming[L1 = Select[L, VertexConnectivity[#] == 6 &];]

with(GraphTheory):
L:=ImportGraph("C:/Users/asus/Desktop/op21new.g6", graph6, output=list): # Change this line
L2:=CodeTools:-Usage(select(g->VertexConnectivity(g)=6,L)):

Because Mapleprimes does not support graph6 format file uploading, I changed it to TXT format. If you want to use it, you only need to change the suffix name.

op21new.txt

Hi, I'm trying to solve auxilary equation to find its familes but I don't know what I'm doing wrong as I'm using following code:

famtemp := (diff(z(xi), xi))^2-a*z(xi)^2-b*z(xi)^3-c*z(xi)^4;

fam1 := simplify(`assuming`([dsolve(famtemp)], [b::real, a::real, c::real, -4*a*c+b^2 > 0, a > 0]))

I want to get the following family:

fam1 := 2*a*sech(sqrt(a)*xi)/(sqrt(-4*a*c+b^2)-b*sech(sqrt(a)*xi));

I hope someone will help me to solve it.

Thanks

I'm trying to execute a code but i am having the following error:

Error, cannot determine if this expression is true or false: 257^(1/2) < -79999999/10000000

The entire procedure is downloadable here: https://www.mediafire.com/file/3iiwmipruhtlhzx/Newton+Bairstow-+proyecto1.mw/file

If someone can help me to find a solution I'll be very thankful.

HOW TO DECIDE THE TRIPLE INTEGRAL IS POSITIVE, NEGATIVE OR ZERO WITHOUT CALCULATING IT?

Download zadelpunten_procedure.mw

Hi! 2 questions

1. I notice that the Curl operator of the VectorCalculus package can't compute the Divergence of a 2D vector field. Of course the most classical case is 3D, but it can also be defined for 2D. Is there any way in Maple to compute the Curl of a 2D vector field using the Curl command?

2. How one can extract the components of a VectorField ? I tried op, GetComponents (LieVectoFields package) etc... but I didn't find a simple answer on the help pages. 

e.g. V1 := VectorField(<-x, -y>, cartesian[x, y])

I want to get {-x,-y}

Many thanks !

Dear all, 

I am trying to use another notation for the inert differential operators in the Physics package (using alias), I am not getting the correct result. Does anyone know how I can solve this issue? Many thanks!

I want to solve a differential equation with piecewise function, but I face an error. I am wondering how to handle it. Thanks

t[1]:=1

x := t -> piecewise(0 <= t and t < t[1], -60*t + 100, t[1] <= t and t <= 10, 1.645*sqrt(480*t))

dsolve({diff(p(t), t) = 2*h*x(t), p(T) = 0}, p(t))

and the error is :

"Error, (in dsolve) found the following equations not depending on the unknowns of the input system: {pT = 0}"

Download Error.mw

I am looking for a robust way to factor an expression (if applicable) to become    x^n*(rest)  as we do it by hand.

edit The input will only be of type `+` and I am looking for a way extract a common factor to convert the input to term^n*(rest) where term is the common factor to pull out.

For example, given  x^2*Y+x and the symbol is given as x  the result will be x*(x*Y+1) and if the input is Y^2*x^3-x^3 then the output is x^3*(Y^2-1) and if there is no common factor x to pull out from all the terms, the output will be the same as the input.

I tried many commands and options, but can't find one method that works all the time for all cases.

For example for   x^2*Y+x  the command factor(x^2*Y+x) gives (Y - 1)*(Y + 1)*x^3 which is not what I want. There is no option to factor to give the name to factor on. And I did not know how to use the last argument of function to do that.

But here simplify(x^2*Y+x) happened to work on this and gives (Y^2 - 1)*x^3 but simplify does not work on first example. simplify(x^2*Y+x) returns the same expression back. So simplify is not reliable to use.

I tried collect, with options factor and simplify. Again, they work on one examples but not others. 

collect(x^2*Y+x,x); does not do it. But collect(Y^2*x^3-x^3,x); works and returns (Y^2 - 1)*x^3 which is what I want.

The problem is that I do not know what the expression looks like. I just know the name x and want to find if there is a common x to any power that can be pulled out to rewite the expression as x^n*(rest) where n is an integer or rational number depending.

This seems like a simple problem. But can't find a Maple command for.   I could ofcourse program it by brute force. Go over each term in the expression, check if each term has a free x to any power in it multiplied by something else, then collect all these x^n term in a list. At end find the x which is raised to lowest power, and then divide the whole expression by it. 

Here is another way I can also try:  Use factor and also collect and also simplify. One at a time. Each time I check if the result is of type `*` but not a division! (check that denom is 1). If so, Then check if result has two operands only. If so, check if op(1,result) is for form x^anything. If so, then one of these cases worked.  Need to try this now to see if it will work on all cases I have. 

Is there a better way to do this in Maple? It has to work on all expresions f(x) without knowing what the expression looks like.

update

I've updated the test cases and included all algorithms given to compare. It is hard in Maple to make a nice table to present results and keep math formatting below.

restart;
makegrid := proc(M::Matrix)#https://www.mapleprimes.com/questions/202902-How-To-Create-Table-Like-Output-For
  uses DocumentTools:-Layout;
  local i,j,m,n,wks;
  m,n := op(1,M);
  wks := Worksheet(Table(alignment=center,width=20,
                         seq(Column(),j=1..n),
                         seq(Row(seq(Cell(Textfield(sprintf("%a",M[i,j]))),
                                     j=1..n)),i=1..m)));
  DocumentTools:-InsertContent(wks);
end proc:

acer_V1_common_factor := proc(x::algebraic, ee::algebraic)
  local p, d := gcd(ee, x^frontend(degree,[ee,x]),'p');
  d * p;
end proc:

acer_V2_common_factor := proc(x, ee) local d, t;
  if ee::`+` then
    t := max(map(proc(u) local r:=frontend(degree,[u,x]);
                         `if`(r::numeric,r,0); end proc,[op(ee)]));
    d := gcd(numer(ee),x^t);
    d*map(u->u/d,ee);
  else ee; end if;
end proc:

dharr_common_factor:=proc(x,z)
  local xn:=x^ldegree(collect(z,x),x);
  if rem(z,xn,x)=0 then xn*quo(z,xn,x) else z end if;
end proc:

me_common_factor:=proc(term,expr)
local tmp;
local T1;

local update_T1:=proc()
T1:= hastype(op(1,tmp),identical(term)^anything) or hastype(op(1,tmp),identical(term));
if not T1 then
   T1:= hastype(op(2,tmp),identical(term)^anything) or hastype(op(2,tmp),identical(term));
fi;
end proc;

if type(expr,`*`) or not has(expr,term) then 
   return expr;
fi;

tmp := collect(expr,term);       
if type(tmp,`*`) and evalb(denom(tmp)=1) and evalb(nops(tmp)=2) then
   update_T1();
   if T1 then
       return tmp;
   fi;
fi;

tmp :=factor(expr);
if type(tmp,`*`) and evalb(denom(tmp)=1) and evalb(nops(tmp)=2) then
    update_T1();
    if T1 then
      return tmp;
    fi;
fi;

tmp := simplify(expr);
if type(tmp,`*`) and evalb(denom(tmp)=1) and evalb(nops(tmp)=2) then
    update_T1();
    if T1 then              
      return tmp;
    fi;
fi;

return expr;
end proc:
############################

test_data:=[[x,x^2*Y+x],
[x,Y^2*x^3-x^3],
[x,x],
[x,x+2*x^2],
[x,x^4*diff(y(x),x)+x^7],
[x,x^4*diff(y(x),x)+x^7-sin(x)],
[y(x),y(x)^4*diff(y(x),x$2)^2*diff(y(x),x)+y(x)^2*diff(y(x),x)+y(x)],
[y(x),y(x)^4*diff(y(x),x$2)^2+y(x)^2*diff(y(x),x)+y(x)^9],
[x,x^4*y^2+x^2*y^2],
[y(x),y(x)^4*diff(y(x),x)^2+y(x)^2*diff(y(x),x)^2],
[diff(y(x),x),y(x)^4*diff(y(x),x)^2+y(x)^2*diff(y(x),x)^2],
[diff(y(x),x),y(x)*diff(y(x),x$2)^2*diff(y(x),x)*sin(x)+diff(y(x),x)^3],
[y(x),diff(y(x),x)-(1+x^(1/2))/(1+y(x)^(1/2))],
[y(x),diff(y(x),x) -(x-1)*y(x)^5/x^2/(-y(x)+2*y(x)^3)],
[y(x),3*y(x)+diff(y(x),x) - 2*x/exp(3*x)],
[x,3*x^2*y^3+7*x/y],
[y,A-(1+x)/(1+y^(1/2))]
]:
RESULT:=Matrix(nops(test_data),6);
for N,item in test_data do
    term:=item[1];
    expr:=item[2];
    RESULT[N,1]:=term; RESULT[N,2]:=expr;
    try
        result:=acer_V1_common_factor(term,expr);
        if type(result,`*`) and denom(result)<>1 then
           RESULT[N,3]:=expr;#bypass, not correct output
        else
           RESULT[N,3]:=result;#accept
        fi;  
    catch:
        RESULT[N,3]:=expr;#reject
    end try;      

    try
        result:=acer_V2_common_factor(term,expr);
        if type(result,`*`) and denom(result)<>1 then
           RESULT[N,4]:=expr;#bypass, not correct output
        else
           RESULT[N,4]:=result;#accept
        fi;  
    catch:
        RESULT[N,4]:=expr;#reject
    end try;      

    try
        result:=dharr_common_factor(term,expr);
        if type(result,`*`) and denom(result)<>1 then
           RESULT[N,5]:=expr;#bypass, not correct output
        else
           RESULT[N,5]:=result;#accept
        fi;  
    catch:
        RESULT[N,5]:=expr;#reject
    end try;      


    try
        result:=me_common_factor(term,expr);
        if type(result,`*`) and denom(result)<>1 then
           RESULT[N,6]:=expr;#bypass, not correct output
        else
           RESULT[N,6]:=result;#accept
        fi;  
    catch:
        RESULT[N,6]:=expr;#reject
    end try;      

od:

RESULT

how_to_do_special_factor.mw

Mapleprime will not let let insert content for some reason. Here is the output as screen shot but it is hard to read. But it is in the above worksheet.

Hello everyone,

I purchased Maple 2021 student version. I am using a Linux Ubuntu 20.04 machine. The machine is my personal computer, so there is no user access privilege restriction. I installed Maple using the GUI, and at the activation step, I get an error that says "Missing host ID for license server". I remember an option for servers or personal PC during download. I am confident that I chose the personal PC option.

Kind regards, and I look forward to hearing from you.

"Taking a list of numeric values L, and producing a list of lists [p,f(p)] for every p in L , is not complicated. In fact it is a quite straightforward and rather basic example of Maple programming"

This sentence i don't understand yet, so i must see a example?

Hey guys,

How can I create a bar chart or a column chart, with specific x values under the bars.

Would be great If someone could help me.

Thank you;) 

Help.mw

How to put a function in the ODE. I have attached below work here.

Thank you

Download Help.mw

The worksheet below contains the desired hyperbolic action and asks for the specific transformation that performs it.

Hyperbolic_Transformation.mw

I have corrected the above worksheet so that the Poincare disk is now centred at [0,0].

I hope this helps you answer my question