Find Unique values in a 2D Tensor using Tensorflow
Following function takes 2D tensor as IP and will return Unique 2D Tensor
def tf_unique_2d(self, x):
x_shape = tf.shape(x) # (3,2)
x1 = tf.tile(x, [1, x_shape[0]]) # [[1,2],[1,2],[1,2],[3,4],[3,4],[3,4]..]
x2 = tf.tile(x, [x_shape[0], 1]) # [[1,2],[1,2],[1,2],[3,4],[3,4],[3,4]..]
x1_2 = tf.reshape(x1, [x_shape[0] * x_shape[0], x_shape[1]])
x2_2 = tf.reshape(x2, [x_shape[0] * x_shape[0], x_shape[1]])
cond = tf.reduce_all(tf.equal(x1_2, x2_2), axis=1)
cond = tf.reshape(cond, [x_shape[0], x_shape[0]]) # reshaping cond to match x1_2 & x2_2
cond_shape = tf.shape(cond)
cond_cast = tf.cast(cond, tf.int32) # convertin condition boolean to int
cond_zeros = tf.zeros(cond_shape, tf.int32) # replicating condition tensor into all 0's
# CREATING RANGE TENSOR
r = tf.range(x_shape[0])
r = tf.add(tf.tile(r, [x_shape[0]]), 1)
r = tf.reshape(r, [x_shape[0], x_shape[0]])
# converting TRUE=1 FALSE=MAX(index)+1 (which is invalid by default) so when we take min it wont get selected & in end we will only take values <max(indx).
f1 = tf.multiply(tf.ones(cond_shape, tf.int32), x_shape[0] + 1)
f2 = tf.ones(cond_shape, tf.int32)
cond_cast2 = tf.where(tf.equal(cond_cast, cond_zeros), f1, f2) # if false make it max_index+1 else keep it 1
# multiply range with new int boolean mask
r_cond_mul = tf.multiply(r, cond_cast2)
r_cond_mul2 = tf.reduce_min(r_cond_mul, axis=1)
r_cond_mul3, unique_idx = tf.unique(r_cond_mul2)
r_cond_mul4 = tf.subtract(r_cond_mul3, 1)
# get actual values from unique indexes
op = tf.gather(x, r_cond_mul4)
return (op)