Copying values within a cluster

[HS JANG]

Hello statalist,

I want to copy values within a cluster as below.

ID	Var1	Var2	Var3
123	1	...	...
123	0	...	...
123	0	...	...
456	2	...	...
456	0	...	...

In this data, the values of Var1 are different, and I want to make it the same in one cluster like this.

ID	Var1	Var2	Var3
123	1	...	...
123	1	...	...
123	1	...	...
456	2	...	...
456	2	...	...

Thanks in advance.

HS JANG

[HS JANG]

Var1 is a kind of dummy variables.

[Carlo Lazzaro]

Please use -dataex- to share example/excerpt of your data with the list. Thanks.
That said:

. input ID Var1

            ID       Var1
  1. 123 1
  2. 123 0
  3. 123 0
  4. 456 2
  5. 456 0
  6. end

. bysort ID: replace Var1=Var1[1]

. list

     +------------+
     |  ID   Var1 |
     |------------|
  1. | 123      1 |
  2. | 123      1 |
  3. | 123      1 |
  4. | 456      2 |
  5. | 456      2 |
     +------------+

.

[HS JANG]

Thank you, Carlo!!

[HS JANG]

Dear Carlo,

What if the dataset are like this?

In this case, unlike before, if there is a value in the second and third ... values, I want to copy the value in same ID.
Thank you in advance.

ID Var
123 1
123 0
123 0
456 0
456 2
789 0
789 0
789 3

->

ID Var
123 1
123 1
123 1
456 2
456 2
789 3
789 3
789 3

[Carlo Lazzaro]

Please use -dataex- to share example/excerpt of your data with the list. Thanks.
That said:

. bysort ID: egen max=max( Var)

. replace Var=max

. drop max

. list

     +-----------+
     |  ID   Var |
     |-----------|
  1. | 123     1 |
  2. | 123     1 |
  3. | 123     1 |
  4. | 456     2 |
  5. | 456     2 |
     |-----------|
  6. | 789     3 |
  7. | 789     3 |
  8. | 789     3 |
     +-----------+

.

[HS JANG]

Dear Carlo,

I appreciate for your reply and kindness.
Thank you!