Here part of data.

```
mydat=structure(list(code = c(123L, 123L, 123L, 123L, 123L, 123L, 123L, 
123L, 123L, 123L, 123L, 123L, 123L, 123L, 123L, 123L, 123L, 123L, 
123L, 123L, 123L, 123L, 123L, 123L, 123L, 123L, 123L, 123L, 123L, 
123L, 123L, 123L, 123L, 123L, 123L, 123L, 123L, 123L, 123L, 123L, 
123L, 123L, 123L, 123L, 123L, 123L, 123L, 222L, 222L, 222L, 222L, 
222L, 222L, 222L, 222L, 222L, 222L, 222L, 222L, 222L, 222L, 222L, 
222L, 222L, 222L, 222L, 222L, 222L, 222L, 222L, 222L, 222L, 222L, 
222L, 222L, 222L, 222L, 222L, 222L, 222L, 222L, 222L, 222L, 222L, 
222L, 222L, 222L, 222L, 222L, 222L, 222L, 222L, 222L, 222L), 
    item = c(234L, 234L, 234L, 234L, 234L, 234L, 234L, 234L, 
    234L, 234L, 234L, 234L, 234L, 234L, 234L, 234L, 234L, 234L, 
    234L, 234L, 234L, 234L, 234L, 234L, 234L, 234L, 234L, 234L, 
    234L, 234L, 234L, 234L, 234L, 234L, 234L, 234L, 234L, 234L, 
    234L, 234L, 234L, 234L, 234L, 234L, 234L, 234L, 234L, 333L, 
    333L, 333L, 333L, 333L, 333L, 333L, 333L, 333L, 333L, 333L, 
    333L, 333L, 333L, 333L, 333L, 333L, 333L, 333L, 333L, 333L, 
    333L, 333L, 333L, 333L, 333L, 333L, 333L, 333L, 333L, 333L, 
    333L, 333L, 333L, 333L, 333L, 333L, 333L, 333L, 333L, 333L, 
    333L, 333L, 333L, 333L, 333L, 333L), return = c(25L, 25L, 
    21L, 37L, 23L, 27L, 19L, 7L, 16L, 12L, 33L, 24L, 6L, 14L, 
    4L, 25L, 90L, 27L, 3L, 16L, 7L, 1L, 13L, 11L, 36L, 5L, 6L, 
    14L, 11L, 41L, 11L, 6L, 4L, 11L, 3L, 6L, 21L, 41L, 28L, 30L, 
    92L, 4L, 1L, 83L, 3L, 16L, 4L, 25L, 25L, 21L, 37L, 23L, 27L, 
    19L, 7L, 16L, 12L, 33L, 24L, 6L, 14L, 4L, 25L, 90L, 27L, 
    3L, 16L, 7L, 1L, 13L, 11L, 36L, 5L, 6L, 14L, 11L, 41L, 11L, 
    6L, 4L, 11L, 3L, 6L, 21L, 41L, 28L, 30L, 92L, 4L, 1L, 83L, 
    3L, 16L, 4L), action = c(0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
    0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
    0L, 0L, 0L, 0L, 0L, 0L, 0L, 1L, 1L, 1L, 1L, 0L, 0L, 0L, 0L, 
    0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
    0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
    0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 1L, 1L, 1L, 1L, 0L, 0L, 
    0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L)), .Names = c("code", 
"item", "return", "action"), class = "data.frame", row.names = c(NA, 
-94L))

```

I have 2 group vars code+item. Here two groups:

```
123 234
222 333

```

Also i have action column. It can have only two values(category) zero(0) or one(1).

i need calculate `90 percentile` by zero category of action of return column, which go before one category of action.
Then i need calculate the `median` by zero category of action of return column, which go before one category of action. (After one we don't touch zeros)

These statistics must be calculate by 14 zeros preceding the one category of action
===================================================================================

Then i have to find values that more 90 percentile which was calculated above, then such values must be replce by the median which was calculated.

After one category of action go zero category again for return column. For it i too have to find value that more 90 percentile which was calculeted above, then such value must be replaced by the median which was calculeted above(when calculate for 14 zeros).

Note the `calculation` is done by 14 zeros preceding the one category of action
but `replacing` by median is done for all `zero category` of action
and performing for each groups `code+item`

The result can be in output column.

to be more clear here desired output.

for `123+234` group
the 90 perc=39,5
median=12

for `222+333`
the 90 perc=39,5
median=12

```
 code item return action output
1   123  234     25      0     25
2   123  234     25      0     25
3   123  234     21      0     21
4   123  234     37      0     16
5   123  234     23      0     23
6   123  234     27      0     27
7   123  234     19      0     19
8   123  234      7      0      7
9   123  234     16      0     16
10  123  234     12      0     12
11  123  234     33      0     33
12  123  234     24      0     24
13  123  234      6      0      6
14  123  234     14      0     14
15  123  234      4      0      4
16  123  234     25      0     25
17  123  234     90      0     **12**
18  123  234     27      0     27
19  123  234      3      0      3
20  123  234     16      0     16
21  123  234      7      0      7
22  123  234      1      0      1
23  123  234     13      0     13
24  123  234     11      0     11
25  123  234     36      0     36
26  123  234      5      0      5
27  123  234      6      0      6
28  123  234     14      0     14
29  123  234     11      0     11
30  123  234     41      0     16
31  123  234     11      1     Na
32  123  234      6      1     Na
33  123  234      4      1     Na
34  123  234     11      1     Na
35  123  234      3      0      3
36  123  234      6      0      6
37  123  234     21      0     21
38  123  234     41      0     **12**
39  123  234     28      0     28
40  123  234     30      0     30
41  123  234     92      0     **12**
42  123  234      4      0      4
43  123  234      1      0      1
44  123  234     83      0     **12**
45  123  234      3      0      3
46  123  234     16      0     16
47  123  234      4      0      4
48  222  333     25      0     25
49  222  333     25      0     25
50  222  333     21      0     21
51  222  333     37      0     16
52  222  333     23      0     23
53  222  333     27      0     27
54  222  333     19      0     19
55  222  333      7      0      7
56  222  333     16      0     16
57  222  333     12      0     12
58  222  333     33      0     33
59  222  333     24      0     24
60  222  333      6      0      6
61  222  333     14      0     14
62  222  333      4      0      4
63  222  333     25      0     25
64  222  333     90      0     **12**
65  222  333     27      0     27
66  222  333      3      0      3
67  222  333     16      0     16
68  222  333      7      0      7
69  222  333      1      0      1
70  222  333     13      0     13
71  222  333     11      0     11
72  222  333     36      0     36
73  222  333      5      0      5
74  222  333      6      0      6
75  222  333     14      0     14
76  222  333     11      0     11
77  222  333     41      0     16
78  222  333     11      1     Na
79  222  333      6      1     Na
80  222  333      4      1     Na
81  222  333     11      1     Na
82  222  333      3      0      3
83  222  333      6      0      6
84  222  333     21      0     21
85  222  333     41      0     **12**
86  222  333     28      0     28
87  222  333     30      0     30
88  222  333     92      0     **12**
89  222  333      4      0      4
90  222  333      1      0      1
91  222  333     83      0     **12**
92  222  333      3      0      3
93  222  333     16      0     16
94  222  333      4      0      4

```

\*\* i marked rows where value was replced by median.