PQL Procedures 
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| PQL Procedures | | Frequencies |
FREQUENCIES procedure produces frequency
counts, histograms and descriptive statistics on numeric variables. Frequency
counts show how many times a variable had a particular value, or had a value
that fell within a specified range. There are four ways of categorising values:
INTEGER
| Produces counts for each discrete integer value. Used for categorical variables or other codes. |
GENERAL
| Produces counts for each discrete value. The expected number of counts must be specified on the command. Used for non-integer numbers with a relatively low number of discrete values. |
CONTINUOUS
| Counts the values that fall into each range. Specify a number of ranges within an overall range so that each range is equal. Used for variables with a large range of values. |
INTERVALS
|
Similar to CONTINUOUS except that each range is
specified individually and may be unequal.
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FREQUENCIES {INTEGER = {varlist | ALL} (min,max) |
GENERAL = {varlist | ALL} (categories) |
CONTINUOUS = {varlist | ALL} (categories,min,max) |
INTERVALS = {varlist | ALL} (intervals)}
[ FILENAME = filename ]
[ STATISTICS = keywordlist ]
[ WEIGHT = varname ]
[ TITLE = 'text' ]
[ HISTOGRAM]
[ ORDER ]
[ NOLABELS ]
[ BOOLEAN = (logical expression) ]
[ SAMPLE = fraction]
Specify one of INTEGER, GENERAL, CONTINUOUS or
INTERVALS. This produces a frequency table with the specified
number of entries. In addition a summary is printed giving counts of Included
Observations (values in the frequency table), Missing Observations (missing and
undefined values) and Rejected Observations (values outside the specified
ranges).
INTEGER
| Specify the numbers to count. One entry is produced for each integer value in the range. |
GENERAL
| Specify the number of discrete values to count. |
CONTINUOUS
| Specify an overall range and a number of equal sub-ranges within this. Values that fall outside of the range are omitted from the frequencies table and are not included in the calculations of the statistics. Specify the overall range by min and max . This is divided into the specified number of equal sized ranges. |
INTERVALS
|
Specify a set of values, in increasing order, that represent the
boundaries of the ranges in the frequency table. Values below the first and
beyond the last value are omitted. For example, to create three ranges for
Salary:
FREQUENCIES INTERVALS =
SALARY (0,2000,3000,9999)
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FILENAME
|
Specify the filename
created by the procedure. If multiple FREQUENCIES statements are specified and no
FILENAME clause is specified on a second or subsequent
command, the output is written to the file specified on the previous
command.If no filename is specified, the output is written to the default output file (the scrolled output buffer in the case of interactive sessions). |
STATISTICS
|
Specify the statistics produced. Specify one or more of the
following keywords:
STATISTICS clause is not specified, statistics are not produced.
|
TITLE
|
Specifies the text on the FREQUENCIES report
subtitle line. Enclose the text in quotes. If TITLE is not
used, the subtitle line is left blank.
|
HISTOGRAM
| Specifies that a histogram is printed in addition to the frequency table. A histogram is a bar chart that displays a frequency distribution the values of a variable. |
WEIGHT
|
Specifies the procedure variable used as a weighting factor for the
variables in FREQUENCIES. Normally, cell counts are
incremented by one for each appropriate occurrence. When a weighting value is
specified, the cell count is incremented by the value in the specified variable.
|
ORDER
| Specifies that the frequency table is printed in increasing order of frequency count (the smallest frequency first), rather than in increasing order of category value that is the default. |
NOLABELS
|
Specifies that variable labels are not printed. By default, the
FREQUENCIES report lists both the variable name and label.
Value labels, if they exist, are printed.
|
BOOLEAN
| Specifies which procedure table records are used by the procedure. The procedure table records for which the logical expression is true are used by the procedure. If this option is not specified, all procedure table records are used. |
SAMPLE
|
Specifies that a random sample of the procedure table records are
used by the procedure. The fraction specifies the percent of records used and is specified as a positive decimal number less than or equal to 1 (one). .25, for example specifies that a 25% sample be used. |
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EDUC) that includes all
statistics:
RETRIEVAL
PROCESS CASES
. PROCESS REC EMPLOYEE
. GET VARS EDUC
. PERFORM PROCS
. END REC
END CASE
FREQUENCIES INTEGER = EDUC (1 , 6) /
FILENAME = FREQS1.TXT /
TITLE = 'Education Levels in Company' /
STATISTICS = ALL /
END RETRIEVAL
The file FREQS1.TXT contains the following report upon completion of the program.
Education Levels in Company
EDUC Education level
VALUE LABEL VALUE ABSOLUTE RELATIVE CUMULATIVE
FREQUENCY FREQUENCY REL FREQ
(PERCENT) (PERCENT)
Elementary 1.00 3.00 15.00 15.00
High School 2.00 2.00 10.00 25.00
Some University 3.00 4.00 20.00 45.00
B.Sc. or B.A. 4.00 6.00 30.00 75.00
M.S. 5.00 3.00 15.00 90.00
Ph.D. 6.00 2.00 10.00 100.00
---------- ------- -------
TOTAL 20.00 100.00 100.00
STATISTICS.....
WGT CNT 20.000 MAXIMUM 6.000
MINIMUM 1.000 MEAN 3.500
STD DEV 1.539 SKEWNESS -0.193
KURTOSIS -0.690 VARIANCE 2.368
STD ERR 0.344 C.V. PCT 43.971
.95 C.I. 2.780 TO 4.220
SUM 70.000 MODE 4.000
MEDIAN 4.000 QUARTILE-25 2.500
QUARTILE-75 4.500
VALID OBSERVATIONS 20
MISSING OBSERVATIONS 0
REJECTED OBSERVATIONS 0
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
RETRIEVAL
PROCESS CASES
. PROCESS REC EMPLOYEE
. GET VARS SALARY
. PERFORM PROCS
. END REC
END CASE
FREQUENCIES CONTINUOUS = SALARY (6 , 1000 , 4000) /
FILENAME = FREQS2.TXT /
STATISTICS = MEAN MEDIAN STDV MIN MAX /
END RETRIEVAL
Output:
SALARY Current monthly salary
LOWER UPPER ABSOLUTE RELATIVE CUMULATIVE
LIMIT LIMIT FREQUENCY FREQUENCY REL FREQ
(PERCENT) (PERCENT)
1500.00 2000.00 1.00 5.00 5.00
2000.00 2500.00 6.00 30.00 35.00
2500.00 3000.00 6.00 30.00 65.00
3000.00 3500.00 5.00 25.00 90.00
3500.00 4000.00 2.00 10.00 100.00
---------- ------- -------
TOTAL 20.00 100.00 100.00
STATISTICS.....
MAXIMUM 4000.000 MINIMUM 1650.000
MEAN 2780.000 STDDEV 573.631
MEDIAN 2750.000
VALID OBSERVATIONS 20
MISSING OBSERVATIONS 0
REJECTED OBSERVATIONS 0
INTEGER clause. Given a choice of modes,
INTEGER is slightly more efficient than
GENERAL.
RETRIEVAL
PROCESS CASES
. PROCESS REC EMPLOYEE
. GET VARS EDUC
. PERFORM PROCS
. END REC
END CASE
FREQUENCIES GENERAL = EDUC (6 ) /
FILENAME = FREQS3.TXT /
TITLE = 'Education Levels in Company' /
END RETRIEVAL
Output:
Education Levels in Company
EDUC Education level
VALUE LABEL VALUE ABSOLUTE RELATIVE CUMULATIVE
FREQUENCY FREQUENCY REL FREQ
(PERCENT) (PERCENT)
Elementary 1.00 3.00 15.00 15.00
High School 2.00 2.00 10.00 25.00
Some University 3.00 4.00 20.00 45.00
B.Sc. or B.A. 4.00 6.00 30.00 75.00
M.S. 5.00 3.00 15.00 90.00
Ph.D. 6.00 2.00 10.00 100.00
---------- ------- -------
TOTAL 20.00 100.00 100.00
STATISTICS.....
VALID OBSERVATIONS 20
MISSING OBSERVATIONS 0
REJECTED OBSERVATIONS 0
RETRIEVAL
PROCESS CASES
. PROCESS REC EMPLOYEE
. GET VARS SALARY
. PERFORM PROCS
. END REC
END CASE
FREQUENCIES INTERVALS =SALARY (1000,2000,3000,3500,4000) /
FILENAME = FREQS4.TXT /
END RETRIEVAL
Output:
SALARY Current monthly salary
LOWER UPPER ABSOLUTE RELATIVE CUMULATIVE
LIMIT LIMIT FREQUENCY FREQUENCY RELFREQ
(PERCENT) (PERCENT)
1000.00 2000.00 1.00 5.00 5.00
2000.00 3000.00 12.00 60.00 65.00
3000.00 3500.00 5.00 25.00 90.00
3500.00 4000.00 2.00 10.00 100.00
---------- ------- -------
TOTAL 20.00 100.00 100.00
STATISTICS....
VALID OBSERVATIONS 20
MISSING OBSERVATIONS 0
REJECTED OBSERVATIONS 0
RETRIEVAL
PROCESS CASES
. PROCESS REC EMPLOYEE
. GET VARS EDUC
. PERFORM PROCS
. END REC
END CASE
FREQUENCIES INTEGER = EDUC(1 , 6) /
FILENAME = FREQS5.TXT /
HISTOGRAM /
END RETRIEVAL
Output:
EDUC Education level
VALUE LABEL VALUE ABSOLUTE RELATIVE CUMULATIVE
FREQUENCY FREQUENCY REL FREQ
(PERCENT) (PERCENT)
Elementary 1.00 3.00 15.00 15.00
High School 2.00 2.00 10.00 25.00
Some University 3.00 4.00 20.00 45.00
B.Sc. or B.A. 4.00 6.00 30.00 75.00
M.S. 5.00 3.00 15.00 90.00
Ph.D. 6.00 2.00 10.00 100.00
---------- ------- -------
TOTAL 20.00 100.00 100.00
EDUC Education level
VALUE
I
1.00 *******************************
I Elementary
I (3.00) 15.00PCT
I
2.00 *********************
I High School
I (2.00)10.00 PCT
I
3.00 *****************************************
I Some University
I (4.00) 20.00 PCT
I
4.00 *******************************************************
I B.Sc. or B.A.
I (6.00) 30.00 PCT
I
5.00 *******************************
I M.S.
I (3.00) 15.00 PCT
I
6.00 *********************
I Ph.D.
I (2.00) 10.00PCT
I
I
I....I....I....I....I....I....I....I....I....I....I
FREQUENCY 0 .5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
STATISTICS.....
VALID OBSERVATIONS 20
MISSING OBSERVATIONS 0
REJECTED OBSERVATIONS 0
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