; Data from StatLib (ftp stat.cmu.edu/datasets)
;
; SUMMARY:
;
; Data from an experiment on the affects of machine adjustments on
; the time to count bolts.  Data appear as the STATS (Issue 10) Challenge.
;
; DATA:
;
; Submitted by W. Robert Stephenson, Iowa State University
;                             email: wrstephe@iastate.edu
;
; A manufacturer of automotive accessories provides hardware, e.g. nuts,
; bolts, washers and screws, to fasten the accessory to the car or truck.
; Hardware is counted and packaged automatically.  Specifically, bolts
; are dumped into a large metal dish.  A plate that forms the bottom of
; the dish rotates counterclockwise.  This rotation forces bolts to the
; outside of the dish and up along a narrow ledge.  Due to the vibration
; of the dish caused by the spinning bottom plate, some bolts fall off
; the ledge and back into the dish.  The ledge spirals up to a point
; where the bolts are allowed to drop into a pan on a conveyor belt.
; As a bolt drops, it passes by an electronic eye that counts it.  When
; the electronic counter reaches the preset number of bolts, the
; rotation is stopped and the conveyor belt is moved forward.
;
; There are several adjustments on the machine that affect its operation.
; These include; a speed setting that controls the speed of rotation
; (SPEED1) of the plate at the bottom of the dish, a total number of
; bolts (TOTAL) to be counted, a second speed setting (SPEED2) that is
; used to change the speed of rotation (usually slowing it down) for the
; last few bolts, the number of bolts to be counted at this second speed
; (NUMBER2), and the sensitivity of the electronic eye (SENS).  The
; sensitivity setting is to insure that the correct number of bolts are
; counted.  Too few bolts packaged causes customer complaints.  Too many
; bolts packaged increases costs.  For each run conducted in this
; experiment the correct number of bolts was counted.  From an
; engineering standpoint if the correct number of bolts is counted, the
; sensitivity should not affect the time to count bolts.  The measured
; response is the time (TIME), in seconds, it takes to count the desired
; number of bolts.  In order to put times on a equal footing the
; response to be analyzed is the time to count 20 bolts (T20BOLT).
; Below are the data for 40 combinations of settings.  RUN is the order
; in which the data were collected.
;
; Analyze the data.  What adjustments have the greatest effect on the
; time to count 20 bolts?  How would you adjust the machine to get
; the shortest time to count 20 bolts?  Are there any unusual features
; to the data?
;
; The data description and data may be freely used for non-commercial
; purposes and can be freely distributed.  Copyright remains with the
; author and STATS Magazine.
;

;relation bolts

;attribute RUN integer
;attribute SPEED1 integer
;attribute TOTAL integer
;attribute SPEED2 integer
;attribute NUMBER2 integer
;attribute SENS integer
;attribute TIME real
;attribute T20BOLT real

;data
(defrelation bolts
(attribute x1 real)
(attribute x2 real)
(attribute x3 real)
(attribute x4 real)
(attribute x5 real)
(attribute x6 real)
(attribute x7 real)
(attribute x8 real)
(data 25  2  10  1.5  0   6    5.70  11.40 )
(data 24  2  10  1.5  0  10   17.56  35.12 )
(data 30  2  10  1.5  2   6   11.28  22.56 )
(data  2  2  10  1.5  2  10    8.39  16.78 )
(data 40  2  10  2.5  0   6   16.67  33.34 )
(data 37  2  10  2.5  0  10   12.04  24.08 )
(data 16  2  10  2.5  2   6    9.22  18.44 )
(data 22  2  10  2.5  2  10    3.94   7.88 )
(data 33  2  30  1.5  0   6   27.02  18.01 )
(data 17  2  30  1.5  0  10   19.46  12.97 )
(data 28  2  30  1.5  2   6   18.54  12.36 )
(data 27  2  30  1.5  2  10   25.70  17.13 )
(data 14  2  30  2.5  0   6   19.02  12.68 )
(data 13  2  30  2.5  0  10   22.39  14.93 )
(data  4  2  30  2.5  2   6   23.85  15.90 )
(data 21  2  30  2.5  2  10   30.12  20.08 )
(data 23  6  10  1.5  0   6   13.42  26.84 )
(data 35  6  10  1.5  0  10   34.26  68.52 )
(data 19  6  10  1.5  2   6   39.74  79.48 )
(data 34  6  10  1.5  2  10   10.60  21.20 )
(data 31  6  10  2.5  0   6   28.89  57.78 )
(data  9  6  10  2.5  0  10   35.61  71.22 )
(data 38  6  10  2.5  2   6   17.20  34.40 )
(data 15  6  10  2.5  2  10    6.00  12.00 )
(data 39  6  30  1.5  0   6  129.45  86.30 )
(data  8  6  30  1.5  0   0  107.38  71.59 )
(data 26  6  30  1.5  2   6  111.66  74.44 )
(data 11  6  30  1.5  2   0  109.10  72.73 )
(data  6  6  30  2.5  0   6  100.43  66.95 )
(data 20  6  30  2.5  0   0  109.28  72.85 )
(data 10  6  30  2.5  2   6  106.46  70.97 )
(data 32  6  30  2.5  2   0  134.01  89.34 )
(data  1  4  20  2.0  1   8   10.78  10.78 )
(data  3  4  20  2.0  1   8    9.39   9.39 )
(data  5  4  20  2.0  1   8    9.84   9.84 )
(data  7  4  20  2.0  1   8   13.94  13.94 )
(data 12  4  20  2.0  1   8   12.33  12.33 )
(data 18  4  20  2.0  1   8    7.32   7.32 )
(data 29  4  20  2.0  1   8    7.91   7.91 )
(data 36  4  20  2.0  1   8   15.58  15.58 )

)