tf.raw_ops.SparseApplyFtrl

Update relevant entries in '*var' according to the Ftrl-proximal scheme.

That is for rows we have grad for, we update var, accum and linear as follows:

$$accum_new = accum + grad * grad$$
$$linear += grad + (accum_{new}^{-lr_{power} } - accum^{-lr_{power} } / lr * var$$
$$quadratic = 1.0 / (accum_{new}^{lr_{power} } * lr) + 2 * l2$$
$$var = (sign(linear) * l1 - linear) / quadratic\ if\ |linear| > l1\ else\ 0.0$$
$$accum = accum_{new}$$

var A mutable Tensor. Must be one of the following types: float32, float64, int32, uint8, int16, int8, complex64, int64, qint8, quint8, qint32, bfloat16, uint16, complex128, half, uint32, uint64. Should be from a Variable().
accum A mutable Tensor. Must have the same type as var. Should be from a Variable().
linear A mutable Tensor. Must have the same type as var. Should be from a Variable().
grad A Tensor. Must have the same type as var. The gradient.
indices A Tensor. Mu