Lokad Logistic Regression kernel using Adrien

LogisticRegression.cs

int ClientsDim = 2276210, ProductsDim = 58989, HDim = 24, LDim = 1;

Vector clients = new Vector("clients", ClientsDim), products = new Vector("products", ProductsDim), labels = new Vector(HDim);

var (W0, W1) = Tensor.TwoD("W0", (HDim, ClientsDim), "i", out Index i, out Index j).Two();
var (b0, b1) = new Scalar("b0", HDim).Two();

var E1 = W0 * clients + b0;
var E2 = W1 * products + b1;
var z = new Scalar("z", SUM[E1 * E2]);