Hi all,
can you help in that please?
How can I use this small procedure (root_of_cheb) as a sub-procedure in  the next procedure (EvalInt) ?
is it possible?

restart:
root_of_cheb:=proc(n)
   local xk,b,k:
   xk:=(k,n)->cos((2*k-1)*Pi/(2*n));
   sort([seq(evalf(xk(k,n)),k=1..n)]):
end:

EvalInt:=proc(f,n)
   local xk:
   xk:=(k,n)->cos((2*k-1)*Pi/(2*n));
   evalf((Pi/n)*add(f(xk(i,n)),i=1..n)):
end:

Thank you

Hi all,

Hope all to be in good health.

I have written following program to obtain minimum  under som constraints but it doesn't work due to some unknown error.

can any one help me?

Program1.mws

best wishes

Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department

print(`output redirected...`); # input placeholder
   d ph                                                     
   ---- = (1 - yc) pc + yh prj + urd prd + ugd pgd - yc ph,
    dt                                                      

     d pc                        d pa               
     ---- = yc ph - (2 - yc) pc, ---- = pc ya - pf,
      dt                          dt                

     d prj                 d prd                     
     ----- = pa yrj + prj, ----- = pa yrd - prd urd,
      dt                    dt                       

     d pgd                     
     ----- = pa ygd - pgd ugd,
      dt                       

     d pf                                          
     ---- = (1 - ygd - yrj - yrd) pa + (1 - yh) prj
      dt                                           
ics := ph(0) = 1, pc(0) = 0, pa(0) = 0, prj(0) = 0, prd(0) = 0, pgd(0) = 0, pf(0) = 0;
print(`output redirected...`); # input placeholder
   ph(0) = 1, pc(0) = 0, pa(0) = 0, prj(0) = 0, prd(0) = 0,

     pgd(0) = 0, pf(0) = 0

i write this equations in maple

but i get this error

Error, (in dsolve) ambiguous input: the variables {pa, pc, pf, pgd, ph, prd, prj} and the functions {pa(0), pc(0), pf(0), pgd(0), ph(0), prd(0), prj(0)} cannot both appear in the system

can anyone help me?

with(PDEtools);
Es := 0.117108e12;
Ef := 0.78125e11;
l := 0.150e-6;
s := 0.500000e-3;
f := 0.5898334197e-6;
o := 0.9e-5;
d := 0.10e-17;
cb := 0.1e7/(19.9);
R := 8.3144621;
T := 298;





PDE := diff(u(x, t), t)-(diff(u(x, t)+o^2*Es*cb*u(x, t)^2/(9*R*T), x, x)) = 0;
IBC := {u(1, t) = 1, u(x, 0) = 0, (D[1](u))(1, t) = l*f/(d*cb)};
S := pdsolve(PDE, IBC, numeric, time = t, range = 0 .. 1, timestep = 0.1e-4, spacestep = 0.1e-6);
p1 := S:-plot(t = .1, numpoints = 100);
Error, (in pdsolve/numeric/plot) unable to compute solution for t>HFloat(0.0):
matrix is singular
p2 := S:-plot(t = .2, numpoints = 50, color = green);
Error, (in pdsolve/numeric/plot) unable to compute solution for t>HFloat(0.0):
matrix is singular
p3 := S:-plot(t = .3, numpoints = 50, color = blue);
Error, (in pdsolve/numeric/plot) unable to compute solution for t>HFloat(0.0):
matrix is singular
plots[display]({p1, p2, p3});
Error, (in plots:-display) expecting plot structures but received: {p1, p2, p3}

i have 3 equations that i need help graphing, i have tried but do not know much about maple.

the equations are x= sin u [7+cos((u/3)-2v)+2cos((u/3)+v)], y=cos u [7+cos((u/3)-2v)+2cos((u/3)+v)],

and z=sin((u/3)-2v)+2sin((u/3)+v) the limits are u from -pi to pi, and v is also from -pi to pi. please help

of the cut-off sphere

?

Of course, with Maple.

What do I have to change to get this animation?

L:=[seq([i,i^2], i=1..4)]:

plots:-animate(plot, [ L[m], m=1..k,

                                style=point, view=[0..4,0..16]

                              ],

                                k=1..4

                     );

Thank you for your help.

Hi,

I m trying to simplify an expression involving square roots in Maple. But instead of giving the expected output it is not simplifying it. Please find the attached maple file for reference. I calculated manually and the result is 1. Please help me out for this. Thanx in advance.

Regards

Sunit

Download question.mw

Hi there, this is my first post in this forum. I hope you can help me with my problem :)

I've created a little program to solve a problem for my class. This is the first time, I wrote a program with Maple, so please don't laugh. 

I've posted the Maple code below:

restart; randomize():
with(plots): with(plottools): with(LinearAlgebra): with(Statistics): with(MTM):

s:={1=2, 3=2}:

Realisierung:=proc(np,volfrac)

local m, h, adresses, rndmAdrs, omega: omega:=Vector[row](np,s);

adresses:=Vector(np-nops(s));

h:=1;
for m from 1 to np do
if(omega[m]=0) then
adresses[h]:=m;
h:=h+1;
end if
od;

randomize():
rndmAdrs:=Shuffle(adresses);

for m from 1 to volfrac*np do
omega[rndmAdrs[m]]:=1
od:

for m from 1 to np -(volfrac*np+nops(s)) do
omega[rndmAdrs[m+int8(volfrac*np)]]:=2
od:

omega;

end:

RealMatrix:=proc(np,nr,volfrac)

local m, alle:

alle:=Matrix(nr,np); for m from 1 to nr do

randomize();

alle[m]:=Realisierung(np,volfrac); od;

alle;

end:

RealMatrix(5,5,0.4);

I used the Shuffle function from Statistics-package to randomly permutate the components in the Vector adresses. Which works fine. By setting Randomize(); I get randomly results vor this permutation, when I execute the whole worksheet.

But when the "Realisierung" procedure is called in the for loop of the "RealMatrix" procedure, always the same Permutation is calculated.

This leads to the fact, that every row in my matrix looks the same.
Like in the example

2 1 2 2 1
2 1 2 2 1
2 1 2 2 1
2 1 2 2 1
2 1 2 2 1

but the lines should be randmly like

2 1 2 2 1
2 2 2 1 1
2 1 2 1 2
2 1 2 2 1
.....

Obvioulsy the problem is in the randomize()-command. I tried to place it directly after "restart" and directly before the Shuffling is executed.
But I had no succes. 

Maybe one of you can help me?
Would be great!
Thanks

How to avoid the error described in the title

Here we have an application to understand how algebraic expressions, calculating degrees relative abosulutos polynomial operations and introduction to work.Here we have an application to understand how algebraic expressions, calculating degrees relative abosulutos polynomial operations and introduction to work.

Grados_de_Polinomios.mw

(in spanish)

Atte.

L.AraujoC.

Hi All,

I want to solve for G, but cant seem to figure it out. Can anyone tell me what am I missing or doing wrong?

SSD:= ((155/9)*2.5)+((155/9)^2/(2*9.807*0.346));
Lc:= 2*SSD-(2*(sqrt(1.08)+sqrt(0.6))^2)/(G+0.04);
Ls:= 2*SSD-(2*(0.6+SSD*tan(Pi/180)))/(G);
Lcon:= 202-Lc-Ls;
Eq:= (G-0.043)(Lc/2)+(-G)(Ls/2)+G*Lcon-0.043*Lc=14;

fsolve(Eq);

thank you

Hi everyone!

I'm curious how to obtain in Maple 2015 same result as in Maple 18.

Here is my code:

restart:

L0 := ImportMatrix("C:\\Test.txt", source = delimited, delimiter = "\t", datatype = float[8]):

plot(L0[() .. (), 1], L0[() .. (), 2], axes = box, size = [600, 320]);

This is result which I get by Maple 18:

This is result which I get by Maple 2015:

My Test file:Test.txt

bags.mw

$15 is spread among four different bags. How  can you can make any whole number of dollars from $1 to $15 by selecting some of these bags of money, without taking any money out of the bags.
 
How is the money distributed ?

One bag must have $1 in it.
To be able to make $2, and each bag is different, so one bag must have $2 in it.
 can now make $3, but can’t make $4, so the third bag must have $4 in it.
With $1, $2 and $4 in three bags, can make every total up to $7. The last bag has the rest of his money in it – $8.

so the answer is $[1,2,4,8]

wondering how to do this with maple procedure. unsurprisingly my code doesn't work

I want to increase the stack limit. but i can not raise it above the hard limit....

so i wonder whether there is a way to increase the hard limit, or at least tell me how much is it?