# Items tagged with operatoroperator Tagged Items Feed

### Non-homogeneous Helmholtz equation...

October 16 2014
0 1

Hello Dears

I have this equation

(Napla)^4 * F(x,y) + k^2 *  (Napla)^2 * F(x,y)= 0,      (1)

which may be written as a non-homgeneous Helmholtz equation as

(Napla)^2 * F(x,y) + k^2 * F(x,y)= g(x,y),                (2)

where the function g(x,y) is a harmonic function and (Napla)^2 is the laplace's operator in two dimension.

Can Maple solve equation (1), it will be better. If not may be solve equation (2).

### How to construct a type for an expression A^n wher...

October 15 2014
2 6

I am trying the following:

restart; with(Physics); with(Library); Setup(mathematicalnotation = true); Setup(op = A);assume(n::integer);type(A^n, Physics:-^(PhysicsType:-ExtendedQuantumOperator, integer));type(A^n, PhysicsType:-ExtendedQuantumOperator^integer);

the result is

false
false

However, I expected to get true in both cases. How to construct correct type for A^n?
Thank you.

### how to construct a table for base 10 for this logi...

September 23 2014
0 0

for base 10

1 op1 5 =

01

op1   12

_________

first digit of first number 1     = 1

first digit of second number 1 = 2

then find 12 in logic table, it is 1, separation is 1 means move the value 1

to left 1 digit become 10

convert 10 back from base 3 to base 10, it is 3

how to construct this unknown name operator table with the custom logic table Min, Except, Diff

based on the operation described

no matter the logic table is correct or not, hope to mechanize these calculation steps for developing 3 operation table for base 10 quickly.

is it possible to develop a new kind of algebra with 3 new operators with the use of 3 operation table?

### when to use if vs. normal if?...

August 19 2014
1 2

I am newbie in Maple, and trying to understand when to use operator if as I see in some code vs. normal if. This is in context if using map()

I noticed I can write

A:=[seq(i,i=1..10)];
f:=x->x^2;
map(x->if(x<5,f(x),NULL),A);

or

map(x->if x<5 then f(x) fi,A);

And they both work the same. When should one use if vs. if? with the case of if I had to give a third argument NULL for the else part, while with using direct "if", I did not have to give the "else" part.

Also, suppose I want to use  IF .. THEN .. ELIF ... FI, then how would this be done using the operator syntax? in normal "if", I can write

A:=[seq(i,i=1..10)];
f:=x->x^2;
map(x->if x<5 then f(x) elif x=5 then x else x-1 fi,A);

Actually if I understand better when if is meant to be used vs. where the normal "if", I might understand more its use.

ps. I did look at the help here but did not see it recommend when to use over the other (unless I overlooked it)

### Inverse Operator Method of Operator D...

August 03 2014
1 4

Dear all,

It's very convenient to define a DE or PDE through Differential Operator D, for example,

((D[1, 1]+D[1, 2]+D[2, 2])(z))(x, y) = exp(x)*sin(y)

Is it possible to realize Inverse Operator Method of Operator D? How to solve the following equation if we rewrite the pde through inverse operator method?

(z)(x, y)=((D[1, 1]+D[1, 2]+D[2, 2])^(-1))exp(x)*sin(y)

Thanks a lot.

### operators in GRTENSORII...

June 05 2014
1 4

how gr operators work?

I tried to run example given there but it is not working,

where can I get more examples to understand working of Gr operators work?

specially for raychaudhuri equations.

### I want to define an differential operator...

March 10 2014
1 1

AOA...I want to introduce an operator to find the derivative of fractional order i.e.,

J^((alpha)) x^(k):=(GAMMA(k+1))/(GAMMA(k-alpha+1))x^(k-alpha):

when i applied J^(1/2) on x^2+x^3 it gives

GAMMA(3)*x^(3/2)/GAMMA(7/2)+GAMMA(4)*x^(5/2)/GAMMA(9/2)

Help.mw

### How to put linear algebra command in a function...

December 09 2013
1 3

Hello,
my question may be simple but I don't find the answer in any help guide.
when I define a function I cannot use a linearalgebra expression such as Trace.
Here is an example of what I would like to do:

If anyone can help me...
Thank you

### Value from operator in plot title...

May 23 2013
0 4

I have a function related to some values and I want to include the value in the title.  So I initially try ...

sine:=(Amp,freq,phase,t)->Amp*sin(2*Pi*freq*t+phase):
plot(sine(1, 2, 0, t), t = 0 .. 1, title = cat(freq, " sine wave cycles"))

but once I use the value in the function it is not remembered, sort of like a subs operation.  A placeholder is the simplest way.

a:=2:
plot(sine(1, a, 0, t), t = 0 .. 1, title = cat(a, " sine wave cycles"))

### How to define left and right derivatives as binary...

February 04 2013
1 2

Dear Maple users,

Is there a way to describe derivatives treated as binary operators in infix notation, in which the derivatives is applied either to the left or right operands. This is useful, for example, when defining generalizations of the Poisson bracket. For a pair of functions f and g, the left and right derivatives are respectively defined as

### How do I apply a range of values to a variable in ...

January 26 2013
1 15

Hello,

I have created a test document to check an equation and I would like to feed a range of k values (ranging from 0 to say 512) in increments of 1) to the main function, and then plot the result as a graph of Zuncomp (y-axis) vs k(x-axis).

I can verify the values of the function by typing say Zuncomp(0) or Zuncomp(10) etc but how do you run this so that you do Zuncomp(k) to read all values of k and generate the output to plot?

Using Maple 13 (Windows 7...

### Run loop for valid inputs...

October 20 2012
0 4
here is my code i want to run the loop for every value if there is invalid input in lhs(ans(1)) the loop should not stop and check for next value
> restart;> > f1 := proc (x) options operator, arrow; R*T*(x*ln(x)+(1-x)*ln(1-x))+Omega[l]*x*(1-x) end proc;x -> R T (x ln(x) + (1 - x) ln(1 - x)) + Omega[l] x (1 - x)> > g1 := proc (x) options operator, arrow; (1-x)*SfA*(T-TfA)+x*SfB*(T-TfB)+R*T*(x*ln(x)+(1-x)*ln(1-x))+Omega[s]*x*(1-x) end proc;

### A problem with using "subs" command...

October 14 2012
0 6

While substituting expressions for θ(t),θ'(t),θ''(t) with some rather simple polynoms (see attached demonstration), the result icludes terms such as "·2" or "θ1·" (see terms multiplying ε8 and ε7in result for C1). It seems MAPLE treates the "·" sign as a variable/constant instead of as an operator. What am I doing wrong?

### Forward Difference Operators in Maple...

August 19 2012
0 2

Hi,

I'm trying to define a simple forward difference operator Δ to act on a function f(n). I have defined, in a number of ways, Δ(f(n)) = f(n+1) - f(n). This works fine but I want Maple to calculate powers of Δ. e.g Δ2 (f(n))= f(n+2) - 2f(n+1) + f(n). As it stands, Maple returns (f(n+1) - f(n))2 seemingly however I define the functions.
What am I doing wrong? Help much appreciated.

DJF

### How to solve differential equation for potential...

July 18 2012
0 1

Dear Maple Users

I wonder how I can use Maple to solve the problem:

for the potential \phi(r). The problem is from the artikle: http://en.wikipedia.org/wiki/Electric-field_screening

I'm particularly puzzled how to implement this differential operator and how to enter the Dirac delta function.

Thanks for any hints.

 1 2 Page 1 of 2
﻿