let svm_regression ?(i=false) p x y =
let b = min 50 (MX.(row_num x) / 2) in
let s = decr_rate in
let t = when_enough in
let l = hinge_loss in
let g = hinge_grad in
let r = l2 in
let o = l2_grad in
let a = 1. /. (float_of_int 100) in
_sgd_basic b s t l g r o a i p x y