What is the Phi function.  And more importantly how do I find out in general waht a symbol represents.  I input Phi in help menu, nothing useful comes up.  I use Function advisor, don't see a Phi symbol or anything beginning with Phi.  Isn't there a way I can select the symbol in the output and get help on it by pressing a F key?

Ok so I try FunctionAdvisor(describe Phi) - it gives me general Lerch Phi function.  But when I go to help page on LerchPhi, nowhere does it use Greek letter Phi to describe the function.  So I finally figured it out as I was composing this question.  But in why does the help page not use the symbol for the function that is displayed in the worksheet?

I can't figure how to use the showsource() command. There are no examples given.

kernelopts(version);
Maple 2017.0, X86 64 WINDOWS, May 17 2017, Build ID 1231047

If I use it on a local proc() it gives an error. Since it needs a file name

f := proc(x) if x <= 2 then print(x); print(x^2) end if; print(-x); x^3 end proc:
showsource(f);

Error, (in fopen) file or directory does not exist

From help:

The showsource command is similar to showstat, but displays the original 
source code corresponding to the requested statements, if that source 
code is available and, in the case of procedures retrieved from 
libraries, kernelopts(keepdebuginfo) is true. If source code is 
not available, showsource raises a warning and then produces 
the same output as showstat.

But there is not one single example of how to use this command. I tried it on a local file (.mpl) in the same folder, but it complained.

restart;
currentdirName :="C:\\bla\\bla";
currentdir(currentdirName);
showsource("maple_proc.mpl");

Error, invalid input: showsource expects its 1st argument, p, 
to be of type {`::`, name}, but received maple_proc.mpl

If I try

showsource(int);
Warning, no source information available; using showstat instead

Just looking for an example on how to use this command. (why help does not show an example?)

HOW to dsolve fractional differential boundary conditions?

FRACTION.mw
 

Download FRACTION.mw

I am getting the following error while calculating function containing diffrential. Thankz in advance
 

Download FUNCTION_(1).mw

I want to solve the system of differential equations
sys :=
  diff(x(t,s),t) = y(t,s),
  diff(y(t,s),t) + x(t,s) = 0;
subject to the initial condition
ic := x(0,s) = a(s),
      y(0,s) = b(s);
where a(s) and b(s) are given.

This looks like a system of PDEs but actually it is a system
of ODEs because there are no derivatives with respect to s.
It is easy to obtain the solution by hand:

x(t,s) = b(s)*sin(t) + a(s)*cos(t)
y(t,s) = b(s)*cos(t) - a(s)*sin(t)

I don't know how to get this in Maple, either through dsolve()
or pdsolve().

Actually both dsolve({sys}) and pdsolve({sys}) do return
the correct general solution, however dsolve({sys, ic})
or pdsolve({sys, ic}) produce no output.  Is there a trick
to make the latter work?

Dear sir,

in the program boundary conditions D(f)(0)=0 doesn't showing result but when use d(f)(0)=1 it will execute, why is this can you explain this ?program.mw
 

Hi everyone,

I am trying to solve the problem described below and it has been runing for days without solving it.

What can I do?
 
Thanks for your help.

Problem:

eq1 := (1/1152)*(81*a1*P^4*b^4*C1^3+162*a1*P^4*b^4*C1*C2^2+648*a1*P^4*b^4*C1*C3^2+432*a1*P^4*b^4*C1*C4^2+864*a1*P^4*b^4*C2*C3*C4+18*a2*P^4*a^2*b^2*C1^3+90*a2*P^4*a^2*b^2*C1*C2^2+90*a2*P^4*a^2*b^2*C1*C3^2+288*a2*P^4*a^2*b^2*C1*C4^2+81*a3*P^4*a^4*C1^3+648*a3*P^4*a^4*C1*C2^2+162*a3*P^4*a^4*C1*C3^2+432*a3*P^4*a^4*C1*C4^2+864*a3*P^4*a^4*C2*C3*C4+288*d1*P^4*b^4*C1+576*d2*P^4*a^2*b^2*C1+288*d3*P^4*a^4*C1+1152*d4*P^4*a^2*b^2*C1+4096*Tc*a^3*b^3*C4)/(b^3*a^3) = 0;

eq2 := (1/1152)*(162*a1*P^4*b^4*C1^2*C2+864*a1*P^4*b^4*C1*C3*C4+81*a1*P^4*b^4*C2^3+432*a1*P^4*b^4*C2*C3^2+648*a1*P^4*b^4*C2*C4^2+90*a2*P^4*a^2*b^2*C1^2*C2+72*a2*P^4*a^2*b^2*C2^3+612*a2*P^4*a^2*b^2*C2*C3^2+360*a2*P^4*a^2*b^2*C2*C4^2+648*a3*P^4*a^4*C1^2*C2+864*a3*P^4*a^4*C1*C3*C4+1296*a3*P^4*a^4*C2^3+432*a3*P^4*a^4*C2*C3^2+2592*a3*P^4*a^4*C2*C4^2+288*d1*P^4*b^4*C2+2304*d2*P^4*a^2*b^2*C2+4608*d3*P^4*a^4*C2+4608*d4*P^4*a^2*b^2*C2-4096*Tc*a^3*b^3*C3)/(b^3*a^3) = 0;

eq3 := (1/1152)*(648*a1*P^4*b^4*C1^2*C3+864*a1*P^4*b^4*C1*C2*C4+432*a1*P^4*b^4*C2^2*C3+1296*a1*P^4*b^4*C3^3+2592*a1*P^4*b^4*C3*C4^2+90*a2*P^4*a^2*b^2*C1^2*C3+612*a2*P^4*a^2*b^2*C2^2*C3+72*a2*P^4*a^2*b^2*C3^3+360*a2*P^4*a^2*b^2*C3*C4^2+162*a3*P^4*a^4*C1^2*C3+864*a3*P^4*a^4*C1*C2*C4+432*a3*P^4*a^4*C2^2*C3+81*a3*P^4*a^4*C3^3+648*a3*P^4*a^4*C3*C4^2+4608*d1*P^4*b^4*C3+2304*d2*P^4*a^2*b^2*C3+288*d3*P^4*a^4*C3+4608*d4*P^4*a^2*b^2*C3-4096*Tc*a^3*b^3*C2)/(b^3*a^3) = 0;

eq4 := (1/144)*(54*a1*P^4*b^4*C1^2*C4+108*a1*P^4*b^4*C1*C2*C3+81*a1*P^4*b^4*C2^2*C4+324*a1*P^4*b^4*C3^2*C4+162*a1*P^4*b^4*C4^3+36*a2*P^4*a^2*b^2*C1^2*C4+45*a2*P^4*a^2*b^2*C2^2*C4+45*a2*P^4*a^2*b^2*C3^2*C4+36*a2*P^4*a^2*b^2*C4^3+54*a3*P^4*a^4*C1^2*C4+108*a3*P^4*a^4*C1*C2*C3+324*a3*P^4*a^4*C2^2*C4+81*a3*P^4*a^4*C3^2*C4+162*a3*P^4*a^4*C4^3+576*d1*P^4*b^4*C4+1152*d2*P^4*a^2*b^2*C4+576*d3*P^4*a^4*C4+2304*d4*P^4*a^2*b^2*C4+512*Tc*a^3*b^3*C1)/(b^3*a^3) = 0;

solve({eq1, eq2, eq3, eq4}, {C1, C2, C3, C4});

hey is there a easy way to make maple solve an equation with similar different variables,

for eksample 

defining the different variables

x_0:=1       x_1:=4           x_2:=10

setting up and equation

solve x * 5

recieving answers for all defined x variables

= [5,20,50]

 The font plot option has no color parameter. 

Suppose I have an expression like

Is it possible to reverse the divergence expression using homotopy operator to obtain Psi and Phi?

The above divergence expression is possible since Euler operator of the left side is zero.

So, I'm trying to delelop an algorithm for the method of multiple scales. Starting with a simple ODE:

After scaling, it should be written in the form:

A proto-algorithm would be:

restart;
ode := diff(x(t), `$`(t, 2))+x(t) = 0;
i_ini := 1; i_fin := 3; j_ini := 0; j_fin := 2;
PDEtools:-dchange({t = sum(epsilon^j*T[j], j = j_ini .. j_fin), x(t) = sum(epsilon^i*X[i](T[1]), i = i_ini .. i_fin)}, ode, [{T[0], T[1], T[2]}, {X[1], X[2], X[3]}])

It is not working, though. Could anyone help me out?

Thanks in advance.

Dear all, 

I have a procedure in Maple. Input is a list. The procedure should add to a list the list [6,5,4,3,2,1] and find if there are repetitions in this new list. After, if there are repetitions, it should return [NO, initial list] and if there are no repetitions, it should find how many elements of the first 5 are larger than the 6th element and return this number together with the sorted list - [6,5,4,3,2,1] in reverse order. (It sounds a bit strange but it's actually computing some sheaf cohomologies).

The problem is, when there are repetitions, the procedure returns an array, and if there are no repetitions, it returns exprseq. I would like both to be an array. Where's the mistake?

For example, coh([4, 0, 0, 0, 0, 4]) is an array and coh([0, 0, 0, 0, 0, 12]) is exprseq.

Here's the text of the program:

restart;
with(combinat);
with(ListTools);
n:=6;

coh := proc (L::list)

Hm := Array([0, 0]);

b := 0;

M := L+[6, 5, 4, 3, 2, 1];

a := evalb(ListTools:-FindRepetitions(M) = []);

if a = false then Hm := Array(['NO', L]) else

for i to 5 do if M[i] < M[6] then b := b+1

end if; 

end do;

K := sort(M);

KK := K+[-1, -2, -3, -4, -5, -6];

for j to n do

M[j] := KK[n-j+1]

end do;

Hm[1] := b;

Hm[2] := M;

print(Hm)

end if

end proc

Dear all,

I use the following statment (without numerical values)

if        IT<20     then        IT:=IT+1            

 if    ZUM<(0.1)^(8);    IT=20;         else;    

for i from 1 to 10   do                               YU[i]:=U[i];                  od;    

for i from 2 to 9 do                           DU1:=YU[i+1]- YU[i-1];        od:      

end if;    

ZUM:=U[1]-YU[1];  

end if;  

the following error occur

where is the problem.

Hi all, I'm using text box and push button to create my user interface for my system. I  wish to use a if..then function to check some condition, if the condition is true then do statement and print out in the text box. When is key coding in the push button and click the push button, then if ...then function not working and the result that not suitable for the condition also have been printed out in text box.So,can someone help my to solve the problem?

Here in the coding i did

use DocumentTools in 

Do (C = %txtC);
Do (p = %txtpk1);
Do (q = %txtpk2);
Do (d = %txtpk3);
Do (A1 = %txtA1);
Do (A2 = %txtA2);
Do (w = `mod`((C*d), A2));
Do (mp = `mod`(w^((p+1)*(1/4)), p));
Do (mq = `mod`(w^((q+1)*(1/4)), q));
Do (hl = `mod`((mp-mq)/p, q));
Do (h2 = `mod`((-mp-mq)/p, q));
Do (m1 = mp+(hl*p));
Do (m2 = mp+(h2*p));
Do (m3 = (p*q)-m1);
Do (m4 = (p*q)-m2);
if m1 <= 2^(2*k-1) then t1 := (C+(-A1*(m1^2)))/A2 end if;
Do (t1);
if m2 <= 2^(2*k-1) then t2 := (C+(-A1*(m2^2)))/A2 end if;
Do (t2);
if m3 <= 2^(2*k-1) then t3 := (C+(-A1*(m3^2)))/A2 end if;
Do (t3);
if m4 <= 2^(2*k-1) then t4 := (C+(-A1*(m4^2)))/A2 end if;
Do (t4);

Do (%txtw = w);
Do (%txtm1 = m1);
Do (%txtm2 = m2);
Do (%txtm3 = m3);
Do (%txtm4 = m4);
Do (%txtt1 = t1);
Do (%txtt2 = t2);
Do (%txtt3 = t3);
Do (%txtt4 = t4);
end use; 
 

Thabk you.