Hi All,
In the following table I'm trying to create Switch_from_start :
start_ind: I created this value to secure when name = "Start" as the first item within the same ID after sorted in descending order.
Data df;
set df;
if name = "Start" then start_ind = 1;
run;
proc sort data = df; by ID Name descending start_id; run;
/*In the table below Name is not sorted*/
switch_from_start : any change in Value in comparing to the Value when name = "Start" within the same ID. So if a different Value within the same ID occurs, switch_from_start will be "yes" + start_value + later appeared Value that is different than the start Value. (refer to output example below)
ID | Name | Value | Start_ind | Switch_from_start |
|
1 | Start | 1 | 1 | no |
|
1 | apple | 1 |
|
|
|
1 | pear | 1 |
|
|
|
2 | Start | 2 | 1 | Yes, 2_1 |
|
2 | apple | 2 |
|
|
|
2 | peach | 2 |
|
|
|
2 | pear | 1 |
|
|
|
2 | guava | 1 |
|
|
|
2 | banana | 2 |
|
|
|
3 | Start | 1 | 1 | Yes, 1_2 |
|
3 | apple | 2 |
|
|
|
3 | peach | 2 |
|
|
|
3 | pear | 1 |
Use a double DOW loop:
data have;
infile datalines truncover;
input ID $ Name $ value start_ind;
datalines;
1 Start 1 1
1 apple 1
1 pear 1
2 Start 2 1
2 apple 2
2 peach 2
2 pear 1
2 guava 1
2 banana 2
3 Start 1 1
3 apple 2
3 peach 2
3 pear 1
;
data want;
if 0 then set have; /* sets variable order */
length switch_from_start $10;
switch_from_start = 'no';
do until (last.id);
set have;
by id;
if first.id
then startval = value;
else if startval ne value and switch_from_start = 'no'
then switch_from_start = catx(' ','Yes,',cats(startval,'_',value));
end;
do until (last.id);
set have;
by id;
output;
switch_from_start = '';
end;
drop startval;
run;
proc print data=want noobs;
run;
Result:
switch_ start_ from_ ID Name value ind start 1 Start 1 1 no 1 apple 1 . 1 pear 1 . 2 Start 2 1 Yes, 2_1 2 apple 2 . 2 peach 2 . 2 pear 1 . 2 guava 1 . 2 banana 2 . 3 Start 1 1 Yes, 1_2 3 apple 2 . 3 peach 2 . 3 pear 1 .
What are the rules for generating switch_within and switch_from_start
switch_from_start : any change in Value in comparing to the Value when name = "Start" within the same ID. So if a different value within the same ID occurs, switch_from_start will be "yes" + start_value + later appeared value that is different than the start value. (see table for output example)
switch_within: combine the before and after values within the same ID if a change occurs. (see table for output example)
Are those what you are looking for?
Use a double DOW loop:
data have;
infile datalines truncover;
input ID $ Name $ value start_ind;
datalines;
1 Start 1 1
1 apple 1
1 pear 1
2 Start 2 1
2 apple 2
2 peach 2
2 pear 1
2 guava 1
2 banana 2
3 Start 1 1
3 apple 2
3 peach 2
3 pear 1
;
data want;
if 0 then set have; /* sets variable order */
length switch_from_start $10;
switch_from_start = 'no';
do until (last.id);
set have;
by id;
if first.id
then startval = value;
else if startval ne value and switch_from_start = 'no'
then switch_from_start = catx(' ','Yes,',cats(startval,'_',value));
end;
do until (last.id);
set have;
by id;
output;
switch_from_start = '';
end;
drop startval;
run;
proc print data=want noobs;
run;
Result:
switch_ start_ from_ ID Name value ind start 1 Start 1 1 no 1 apple 1 . 1 pear 1 . 2 Start 2 1 Yes, 2_1 2 apple 2 . 2 peach 2 . 2 pear 1 . 2 guava 1 . 2 banana 2 . 3 Start 1 1 Yes, 1_2 3 apple 2 . 3 peach 2 . 3 pear 1 .
PS note how I presented the example dataset in a data step with datalines. It allows everybody else to safely recreate your dataset exactly with just a simple copy/paste and submit. Please present data in that way in the future; it's not really complicated and speeds up finding a solution for you. Help us to help you.
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