gram

gram(ds, [colNames], [subMean], [normalize])

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.

Calculate the Gram matrix of the selected columns in the given table. With a given matrix A, the result is A.tranpose() dot A.

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);