gram
Syntax
gram(ds, [colNames], [subMean], [normalize])
Arguments
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.
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
.
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 |