gram
Syntax
gram(ds, [colNames], [subMean], [normalize])
Details
Calculate the Gram matrix of the selected columns in the given table. With a given
matrix A, the result is A.tranpose() dot A.
Parameters
ds is one or multiple data source. It is usually generated by function sqlDS.
colNames (optional) is a STRING vector indicating column names. The default value is all columns names in ds.
subMean (optional) is a Boolean value indicating whether to substract from each column its mean. The default value is true.
normalize (optional) is a Boolean value indicating whether to divide each column by its standard deviation. The default value is false.
Returns
A matrix.
Examples
x = [7,1,1,0,5,2]
y = [0.7, 0.9, 0.01, 0.8, 0.09, 0.23]
t=table(x, y)
ds = sqlDS(<select * from t>);
gram(ds);
| #0 | #1 |
|---|---|
| 37.333333 | -0.56 |
| -0.56 | 0.75895 |
