## 250 Reputation

1 years, 165 days

## How to Simplified this expression with ...

Maple

Hello,every one :

There is a recursive formula where parameters a,b,c and d are real numbers with a>=b, c>=d;

```rsolve({f(n+1)-((a-1)*(b-1)+(c+d))*f(n)-c*d*f(n-1)=0, f(0)=a,f(1)=a*(b - 1)+c},f):
simplify(%)
```

Final expression is too complex, If possible，I'd like to get a more concise expression.
The screenshots of my running results are as follows：

## How save the members in set in the or...

Maple

I  want save a set as shown below:

`E:={{1,2,3,4,5,6},{4,5,6,7,8,9,10,11},{10,11,12,13,14}};`
E := {{10, 11, 12, 13, 14}, {1, 2, 3, 4, 5, 6}, {4, 5, 6, 7, 8, 9, 10, 11}}

The order of set is changed; I have known the list can do it following my order,
`       E:=[{1,2,3,4,5,6},{4,5,6,7,8,9,10,11},{10,11,12,13,14}];`
but I want to know what can I do in set?

## How to determine Number of members of se...

Maple
Hello:
I have a set like following:

Set:={{1, 2}, {1, 3}, {1, 4}, {2, 3}};
I want to determine number of every member of set?
for example:  1 appears 3 times. 2 appears 2 times,
3 appears 2 times , 4 appears 1 time.

How to do?

## How to set up the the output format of g...

Maple

Hi:
I use the following codes:
with(GraphTheory):
Graphs_data3:=[NonIsomorphicGraphs(6,restrictto =[connected], output
= graphs, outputform =graph)]:
Diameter2_select:=select[flatten](t->Diameter(t)=2,Graphs_data3):
map(DrawGraph,Diameter2_select);
nops(Diameter2_select);

Since  59 graphs are not many, so,I want to display  it. But the list show that
[Length of output exceeds limit of 1000000]`
How do I do?

If I use DrawGraph(Diameter2_select), the output is to large, and it is  not convenient to print it out .

## How to get more graphs with given seq...

Maple 2018

We know the following facts:

The SequenceGraph command returns a graph with the specified degree sequence given as input, if such a graph exists. It raises an exception otherwise.
But  If I  want to get more graphs  that satisfy this condition of degree sequence ? (If graphs are not many ,I want get all graphs better)
what should I do.?
For example: DrawGraph(SequenceGraph([3, 2, 2, 1, 1, 1]));  It returns the first graph below, but it is obvious that the second graph also fits the condition.

squenceGraph.mw

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