APPLY_PCA

Transforms the data using a PCA model.

Transforms the data using a PCA model. This returns new coordinates of each data point.

Syntax

APPLY_PCA ( input-columns
        USING PARAMETERS model_name = 'model-name'
            [, num_components = num-components]
            [, cutoff = cutoff-value]
            [, match_by_pos = match-by-position]
            [, exclude_columns = 'excluded-columns']
            [, key_columns = 'key-columns'] )

Arguments

input-columns

Comma-separated list of columns that contain the data matrix, or asterisk (*) to select all columns. The following requirements apply:

All columns must be a numeric data type.
Enclose the column name in double quotes if it contains special characters.

Parameters

model_name

Name of the model (case-insensitive).

num_components

The number of components to keep in the model. This is the number of output columns that will be generated. If you omit this parameter and the cutoff parameter, all model components are kept.

cutoff

Set to 1, specifies the minimum accumulated explained variance. Components are taken until the accumulated explained variance reaches this value.

match_by_pos

Boolean value that specifies how input columns are matched to model features:

false (default): Match by name.
true: Match by the position of columns in the input columns list.

exclude_columns

Comma-separated list of column names from input-columns to exclude from processing.

key_columns

Comma-separated list of column names from input-columns that identify its data rows. These columns are included in the output table.

Examples


=> SELECT PCA ('pcamodel', 'world','country,HDI,em1970,em1971,em1972,em1973,em1974,em1975,em1976,em1977,
em1978,em1979,em1980,em1981,em1982,em1983,em1984 ,em1985,em1986,em1987,em1988,em1989,em1990,em1991,em1992,
em1993,em1994,em1995,em1996,em1997,em1998,em1999,em2000,em2001,em2002,em2003,em2004,em2005,em2006,em2007,
em2008,em2009,em2010,gdp1970,gdp1971,gdp1972,gdp1973,gdp1974,gdp1975,gdp1976,gdp1977,gdp1978,gdp1979,gdp1980,
gdp1981,gdp1982,gdp1983,gdp1984,gdp1985,gdp1986,gdp1987,gdp1988,gdp1989,gdp1990,gdp1991,gdp1992,gdp1993,
gdp1994,gdp1995,gdp1996,gdp1997,gdp1998,gdp1999,gdp2000,gdp2001,gdp2002,gdp2003,gdp2004,gdp2005,gdp2006,
gdp2007,gdp2008,gdp2009,gdp2010' USING PARAMETERS exclude_columns='HDI,country');
PCA
---------------------------------------------------------------
Finished in 1 iterations.
Accepted Rows: 96  Rejected Rows: 0
(1 row)
=> CREATE TABLE worldPCA AS SELECT
APPLY_PCA (HDI,country,em1970,em1971,em1972,em1973,em1974,em1975,em1976,em1977,em1978,em1979,
em1980,em1981,em1982,em1983,em1984 ,em1985,em1986,em1987,em1988,em1989,em1990,em1991,em1992,em1993,em1994,
em1995,em1996,em1997,em1998,em1999,em2000,em2001,em2002,em2003,em2004,em2005,em2006,em2007,em2008,em2009,
em2010,gdp1970,gdp1971,gdp1972,gdp1973,gdp1974,gdp1975,gdp1976,gdp1977,gdp1978,gdp1979,gdp1980,gdp1981,gdp1982,
gdp1983,gdp1984,gdp1985,gdp1986,gdp1987,gdp1988,gdp1989,gdp1990,gdp1991,gdp1992,gdp1993,gdp1994,gdp1995,
gdp1996,gdp1997,gdp1998,gdp1999,gdp2000,gdp2001,gdp2002,gdp2003,gdp2004,gdp2005,gdp2006,gdp2007,gdp2008,
gdp2009,gdp2010 USING PARAMETERS model_name='pcamodel', exclude_columns='HDI, country', key_columns='HDI,
country',cutoff=.3)OVER () FROM world;
CREATE TABLE

=> SELECT * FROM worldPCA;
HDI   |       country       |       col1
------+---------------------+-------------------
0.886 | Belgium             |  79002.2946705704
0.699 | Belize              | -25631.6670012556
0.427 | Benin               | -40373.4104598122
0.805 | Chile               | -16805.7940082156
0.687 | China               | -37279.2893141103
0.744 | Costa Rica          | -19505.5631231635
0.4   | Cote d'Ivoire       | -38058.2060339272
0.776 | Cuba                | -23724.5779612041
0.895 | Denmark             |  117325.594028813
0.644 | Egypt               | -34609.9941604549
...
(96 rows)

=> SELECT APPLY_INVERSE_PCA (HDI, country, col1
    USING PARAMETERS model_name = 'pcamodel', exclude_columns='HDI,country',
    key_columns = 'HDI, country') OVER () FROM worldPCA;
HDI  |       country       |      em1970       |      em1971       |      em1972      |      em1973      |
      em1974      |      em1975       |      em1976|      em1977      |      em1978       |      em1979
   |      em1980       |      em1981      |      em1982       |      em1983       |      em1984       |em1985
|      em1986       |      em1987       |      em1988       |      em1989      |      em1990      |      em1991
|      em1992       |      em1993|      em1994      |      em1995       |      em1996       |      em1997
    |      em1998       |      em1999       |      em2000       |      em2001       |em2002       |
em2003      |      em2004       |      em2005      |      em2006       |      em2007       |      em2008
|      em2009      |      em2010       |     gdp1970      |     gdp1971      |     gdp1972      |     gdp1973
|     gdp1974      |     gdp1975      |     gdp1976      |     gdp1977      |gdp1978      |     gdp1979
 |     gdp1980      |     gdp1981      |     gdp1982      |     gdp1983      |     gdp1984      |     gdp1985
      |     gdp1986|    gdp1987      |     gdp1988      |     gdp1989      |     gdp1990      |     gdp1991
     |     gdp1992      |     gdp1993      |     gdp1994      |     gdp1995      |     gdp1996      |
gdp1997      |     gdp1998      |     gdp1999      |     gdp2000      |     gdp2001      |     gdp2002
|     gdp2003      |gdp2004      |     gdp2005      |     gdp2006      |     gdp2007      |     gdp2008
  |     gdp2009      |     gdp2010
-------+---------------------+-------------------+-------------------+------------------+------------------
+------------------+-------------------+------------------+------------------+-------------------+---------
----------+-------------------+------------------+-------------------+-------------------+-----------------
--+------------------+-------------------+-------------------+-------------------+------------------+-------
-----------+------------------+-------------------+-------------------+------------------+------------------
-+-------------------+------------------+-------------------+-------------------+-------------------+-------
------------+--------------------+------------------+-------------------+------------------+----------------
---+-------------------+-------------------+------------------+-------------------+------------------+------
------------+------------------+------------------+------------------+------------------+------------------+
------------------+------------------+------------------+------------------+------------------+-------------
-----+------------------+------------------+------------------+------------------+------------------+-------
-----------+------------------+------------------+------------------+------------------+------------------+-
-----------------+------------------+------------------+------------------+------------------+--------------
----+------------------+------------------+------------------+------------------+------------------+--------
----------+------------------+------------------+------------------+------------------+------------------
0.886 | Belgium             |  18585.6613572407 | -16145.6374560074 |  26938.956253415 | 8094.30475779595 |
 12073.5461203817 | -11069.0567600181 | 19133.8584911727|   5500.312894949 | -4227.94863799987 |  6265.77925410752
|  -10884.749295608 | 30929.4669575201 | -7831.49439429977 |  3235.81760508742 | -22765.9285442662 | 27200
.6767714485 | -10554.9550160917 |   1169.4144482273 | -16783.7961289161 | 27932.2660829329 | 17227.9083196848
| 13956.0524012749 | -40175.6286481088 | -10889.4785920499 | 22703.6576872859 | -14635.5832197402 |
2857.12270512168 | 20473.5044214494 | -52199.4895696423 | -11038.7346460738 |  18466.7298633088 | -17410.4225137703 |
-3475.63826305462 | 29305.6753822341 |   1242.5724942049 | 17491.0096310849 | -12609.9984515902 | -17909.3603476248
|  6276.58431412381 | 21851.9475485178 | -2614.33738160397 | 3777.74134131349 | 4522.08854282736 | 4251.90446379366
| 4512.15101396876 | 4265.49424538129 | 5190.06845330997 | 4543.80444817989 | 5639.81122679089 | 4420.44705213467
|  5658.8820279283 | 5172.69025294376 | 5019.63640408663 | 5938.84979495903 | 4976.57073629812 | 4710.49525137591
| 6523.65700286465 | 5067.82520773578 | 6789.13070219317 | 5525.94643553563 | 6894.68336419297 | 5961.58442474331
| 5661.21093840818 | 7721.56088518218 |  5959.7301109143 | 6453.43604137202 | 6739.39384033096 | 7517.97645468455
| 6907.49136910647 | 7049.03921764209 | 7726.49091035527 | 8552.65909911844 | 7963.94487647115 | 7187.45827585515
| 7994.02955410523 | 9532.89844418041 | 7962.25713582666 | 7846.68238907624 | 10230.9878908643 | 8642.76044946519
| 8886.79860331866 |  8718.3731386891
...
(96 rows)

APPLY_PCA

Syntax

Arguments

Parameters

Examples

See also