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| Functions and CALL Routines |
INTFIT Function
Returns a time interval that is aligned between two dates.
| Category: | Date and Time |
Syntax |
| INTFIT(argument-1, argument-2, 'type') |
Arguments
- argument
-
specifies a SAS expression that represents a SAS date or datetime value, or an observation.
Tip: Observation numbers are more likely to be used as arguments if date or datetime values are not available. - 'type'
-
specifies whether the arguments are SAS date values, datetime values, or observations.
The following values for type are valid:
d specifies that argument-1 and argument-2 are date values.
dt specifies that argument-1 and argument-2 are datetime values.
obs specifies that argument-1 and argument-2 are observations.
| Details |
The INTFIT function returns the most likely time interval based on two dates, datetime values, or observations that have been aligned within an interval. INTFIT assumes that the alignment value is SAME, which specifies that the date is aligned to the same calendar date with the corresponding interval increment. For more information about the alignment argument, see INTNX Function.
If the arguments that are used with INTFIT are observations, you can determine the cycle of an occurrence by using observation numbers. In the following example, the first two arguments of INTFIT are observation numbers, and the type argument is obs . If Jason used the gym the first time and the 25th time that a researcher recorded data, you could determine the interval by using the following statement: interval=intfit(1,25,'obs'); . In this case, the value of interval is OBS24.2.
For information about time series, see the SAS/ETS User's Guide.
The INTFIT function can also be used with calendar intervals from the retail industry. These intervals are ISO 8601 compliant. For more information, see Retail Calendar Intervals: ISO 8601 Compliant in SAS Language Reference: Concepts.
| Examples |
Example 1: Finding Intervals That Are Aligned between Two Dates
The following example shows the intervals that are aligned between two dates. The type argument in this example identifies the input as date values.
options pageno=1 nodate ls=80 ps=64; data a; length interval $20; date1='01jan06'd; do i=1 to 25; date2=intnx('day', date1, i); interval=intfit(date1, date2, 'd'); output; end; format date1 date2 date.; run; proc print data=a; run;
Interval Output from the INTFIT Function
The SAS System 1
Obs interval date1 i date2
1 DAY 01JAN06 1 02JAN06
2 DAY2 01JAN06 2 03JAN06
3 DAY3.3 01JAN06 3 04JAN06
4 DAY4.3 01JAN06 4 05JAN06
5 DAY5.3 01JAN06 5 06JAN06
6 DAY6.3 01JAN06 6 07JAN06
7 WEEK 01JAN06 7 08JAN06
8 DAY8.3 01JAN06 8 09JAN06
9 DAY9.9 01JAN06 9 10JAN06
10 TENDAY 01JAN06 10 11JAN06
11 DAY11.6 01JAN06 11 12JAN06
12 DAY12.3 01JAN06 12 13JAN06
13 DAY13.7 01JAN06 13 14JAN06
14 WEEK2.8 01JAN06 14 15JAN06
15 SEMIMON 01JAN06 15 16JAN06
16 DAY16.3 01JAN06 16 17JAN06
17 DAY17.7 01JAN06 17 18JAN06
18 DAY18.9 01JAN06 18 19JAN06
19 DAY19.7 01JAN06 19 20JAN06
20 TENDAY2 01JAN06 20 21JAN06
21 WEEK3.8 01JAN06 21 22JAN06
22 DAY22.17 01JAN06 22 23JAN06
23 DAY23.13 01JAN06 23 24JAN06
24 DAY24.3 01JAN06 24 25JAN06
25 DAY25.3 01JAN06 25 26JAN06
The output shows that if the increment value is one day, then the result of the INTFIT function is DAY. If the increment value is two days, then the result of the INTFIT function is DAY2. If the increment value is three days, then the result is DAY3.3, with a shift index of 3. (If the two input dates are a Friday and a Monday, then the result is WEEKDAY.) If the increment value is seven days, then the result is WEEK.
Example 2: Finding Intervals That Are Aligned between Two Dates When the Dates Are Identified As Observations
The following example shows the intervals that are aligned between two dates. The type argument in this example identifies the input as observations.
options pageno=1 nodate ls=80 ps=64; data a; length interval $20; date1='01jan06'd; do i=1 to 25; date2=intnx('day', date1, i); interval=intfit(date1, date2, 'obs'); output; end; format date1 date2 date.; run; proc print data=a; run;
Interval Output from the INTFIT Function When Dates Are Identified as Observations
The SAS System 1
Obs interval date1 i date2
1 OBS 01JAN06 1 02JAN06
2 OBS2 01JAN06 2 03JAN06
3 OBS3.3 01JAN06 3 04JAN06
4 OBS4.3 01JAN06 4 05JAN06
5 OBS5.3 01JAN06 5 06JAN06
6 OBS6.3 01JAN06 6 07JAN06
7 OBS7.3 01JAN06 7 08JAN06
8 OBS8.3 01JAN06 8 09JAN06
9 OBS9.9 01JAN06 9 10JAN06
10 OBS10.3 01JAN06 10 11JAN06
11 OBS11.6 01JAN06 11 12JAN06
12 OBS12.3 01JAN06 12 13JAN06
13 OBS13.7 01JAN06 13 14JAN06
14 OBS14.3 01JAN06 14 15JAN06
15 OBS15.3 01JAN06 15 16JAN06
16 OBS16.3 01JAN06 16 17JAN06
17 OBS17.7 01JAN06 17 18JAN06
18 OBS18.9 01JAN06 18 19JAN06
19 OBS19.7 01JAN06 19 20JAN06
20 OBS20.3 01JAN06 20 21JAN06
21 OBS21.3 01JAN06 21 22JAN06
22 OBS22.17 01JAN06 22 23JAN06
23 OBS23.13 01JAN06 23 24JAN06
24 OBS24.3 01JAN06 24 25JAN06
25 OBS25.3 01JAN06 25 26JAN06
| See Also |
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Functions:
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