split durations into intervals

[Lutz Kolburg]

Hey Guys,

I would love to hear some suggestions for a problem which puzzles me for
a while:
I have some Eye-Tracking data which is already processed, so each row
represents one fixation. But now I would like to split these fixations
into intervals. The stimulus presentation was 6000ms long and I would
like to split it into 12 intervals á 500ms. The amount of time of each
fixation should be written in  the corresponding interval. As you can
see below I started writing a lot of IF statments, but I'm pretty,
pretty sure that this is not the smartest way. I tried LOOP and other
stuff, but I always failed at the point when I have to point to the
interval depending on the time when the fixation has started. An idea
would be greatly appreciated!

Some example data:

DATA LIST FREE /Fixationstartms Fixationendms.
BEGIN DATA
8 242
278 450
540 690
758 1088
1188 1468
1532 1832
1872 2040
2079 2545
2587 5700
END DATA.

And this is what it should look like:

DATA LIST FREE /Fixationstartms Fixationendms Interval.1 TO Interval.12.
BEGIN DATA
8 242 234 0 0 0 0 0 0 0 0 0 0 0
278 450 171 0 0 0 0 0 0 0 0 0 0 0
540 690 0 150 0 0 0 0 0 0 0 0 0 0
758 1088 0 242 88 0 0 0 0 0 0 0 0 0
1188 1468 0 0 280 0 0 0 0 0 0 0 0 0
1532 1832 0 0 0 300 0 0 0 0 0 0 0 0
1872 2040 0 0 0 128 40 0 0 0 0 0 0 0
2079 2545 0 0 0 0 421 45 0 0 0 0 0 0
2587 5700 0 0 0 0 0 413 500 500 500 500 500 200
END DATA.

This is what I've accomplished so far:

NUMERIC Intervalstart (F2) Intervalend (F2).
LOOP #i = 0 to 6000 by 500.
IF (FixationStartms GE #i AND Fixationstartms LT #i + 500) Intervalstart
= #i.
IF (FixationEndms GE #i  AND Fixationendms LT #i + 500) Intervalend = #i.
END LOOP.
EXECUTE.

RECODE Intervalstart Intervalend (0 = 1) (500 = 2) (1000 = 3) (1500 = 4)
(2000 = 5) (2500 = 6) (3000 =7) (3500 = 8) (4000 = 9) (4500 = 10) (5000
= 11) (5500 = 12) (6000 = 12).
EXECUTE.


NUMERIC Interval.1 to Interval.12 (F4).
DO IF Intervalstart = 1 and Intervalend = 1.
COMPUTE Interval.1 = Fixationendms - Fixationstartms.
ELSE IF Intervalstart = 1 and Intervalend = 2.
COMPUTE Interval.1 = 500 - Fixationstartms.
COMPUTE Interval.2 = Fixationendms - 500.
ELSE IF Intervalstart = 1 and Intervalend = 3.
COMPUTE Interval.1 = 500 - Fixationstartms.
COMPUTE Interval.2 = 500.
COMPUTE Interval.3 = Fixationendms - 500.
END IF.
EXECUTE.

Thank you so much!
Lutz

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-----
DATA LIST FREE /Fixstart Fixend.
BEGIN DATA
8 242
278 450
540 690
758 1088
1188 1468
1532 1832
1872 2040
2079 2545
2587 5700
END DATA.

COMPUTE #IntSt=TRUNC(fixstart/500)+1.
COMPUTE #Intend=  TRUNC(fixend/500)+1  .
VECTOR INT (12).
RECODE INT1 TO INT12 (ELSE=0).
FORMATS INT1 TO INT12 (F3.0).
DO IF #intst=#intend.
+  COMPUTE int(#intst)=Fixend-Fixstart.
ELSE.
+  COMPUTE int(#intst)=#intst*500-fixstart.
+  COMPUTE int(#intend)=fixend-(#intend-1)*500.
+  LOOP #=#intst+1 TO #intend-1.
+    COMPUTE int(#)=500.
+  END LOOP.
END IF.
EXE.
LIST.


FIXSTART   FIXEND INT1 INT2 INT3 INT4 INT5 INT6 INT7 INT8 INT9 INT10 INT11 INT12

8.000000 242.0000  234    0    0    0    0    0    0    0    0    0     0     0
278.0000 450.0000  172    0    0    0    0    0    0    0    0    0     0     0
540.0000 690.0000    0  150    0    0    0    0    0    0    0    0     0     0
758.0000 1088.000    0  242   88    0    0    0    0    0    0    0     0     0
1188.000 1468.000    0    0  280    0    0    0    0    0    0    0     0     0
1532.000 1832.000    0    0    0  300    0    0    0    0    0    0     0     0
1872.000 2040.000    0    0    0  128   40    0    0    0    0    0     0     0
2079.000 2545.000    0    0    0    0  421   45    0    0    0    0     0     0
2587.000 5700.000    0    0    0    0    0  413  500  500  500  500   500   200


Number of cases read:  9    Number of cases listed:  9

Lutz Kolburg wrote

Hey Guys,

I would love to hear some suggestions for a problem which puzzles me for
a while:
I have some Eye-Tracking data which is already processed, so each row
represents one fixation. But now I would like to split these fixations
into intervals. The stimulus presentation was 6000ms long and I would
like to split it into 12 intervals á 500ms. The amount of time of each
fixation should be written in  the corresponding interval. As you can
see below I started writing a lot of IF statments, but I'm pretty,
pretty sure that this is not the smartest way. I tried LOOP and other
stuff, but I always failed at the point when I have to point to the
interval depending on the time when the fixation has started. An idea
would be greatly appreciated!

Some example data:

DATA LIST FREE /Fixationstartms Fixationendms.
BEGIN DATA
8 242
278 450
540 690
758 1088
1188 1468
1532 1832
1872 2040
2079 2545
2587 5700
END DATA.

And this is what it should look like:

DATA LIST FREE /Fixationstartms Fixationendms Interval.1 TO Interval.12.
BEGIN DATA
8 242 234 0 0 0 0 0 0 0 0 0 0 0
278 450 171 0 0 0 0 0 0 0 0 0 0 0
540 690 0 150 0 0 0 0 0 0 0 0 0 0
758 1088 0 242 88 0 0 0 0 0 0 0 0 0
1188 1468 0 0 280 0 0 0 0 0 0 0 0 0
1532 1832 0 0 0 300 0 0 0 0 0 0 0 0
1872 2040 0 0 0 128 40 0 0 0 0 0 0 0
2079 2545 0 0 0 0 421 45 0 0 0 0 0 0
2587 5700 0 0 0 0 0 413 500 500 500 500 500 200
END DATA.

This is what I've accomplished so far:

NUMERIC Intervalstart (F2) Intervalend (F2).
LOOP #i = 0 to 6000 by 500.
IF (FixationStartms GE #i AND Fixationstartms LT #i + 500) Intervalstart
= #i.
IF (FixationEndms GE #i  AND Fixationendms LT #i + 500) Intervalend = #i.
END LOOP.
EXECUTE.

RECODE Intervalstart Intervalend (0 = 1) (500 = 2) (1000 = 3) (1500 = 4)
(2000 = 5) (2500 = 6) (3000 =7) (3500 = 8) (4000 = 9) (4500 = 10) (5000
= 11) (5500 = 12) (6000 = 12).
EXECUTE.


NUMERIC Interval.1 to Interval.12 (F4).
DO IF Intervalstart = 1 and Intervalend = 1.
COMPUTE Interval.1 = Fixationendms - Fixationstartms.
ELSE IF Intervalstart = 1 and Intervalend = 2.
COMPUTE Interval.1 = 500 - Fixationstartms.
COMPUTE Interval.2 = Fixationendms - 500.
ELSE IF Intervalstart = 1 and Intervalend = 3.
COMPUTE Interval.1 = 500 - Fixationstartms.
COMPUTE Interval.2 = 500.
COMPUTE Interval.3 = Fixationendms - 500.
END IF.
EXECUTE.

Thank you so much!
Lutz

=====================
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[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
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