Possible data leakage in quantum/docs/tutorials /quantum_data.ipynb

[OkuyanBoga]

Hi all,

I think there is a possible data leakage in quantum data tutorial in

quantum/docs/tutorials/quantum_data.ipynb

Lines 783 to 790 in 8487280

	"S_pqk, V_pqk = get_spectrum(\n",
	" tf.reshape(tf.concat([x_train_pqk, x_test_pqk], 0), [-1, len(qubits) * 3]))\n",
	"\n",
	"S_original, V_original = get_spectrum(\n",
	" tf.cast(tf.concat([x_train, x_test], 0), tf.float32), gamma=0.005)\n",
	"\n",
	"print('Eigenvectors of pqk kernel matrix:', V_pqk)\n",
	"print('Eigenvectors of original kernel matrix:', V_original)"

when calculating

quantum/docs/tutorials/quantum_data.ipynb

Line 731 in 8487280

" S, V = tf.linalg.eigh(KC_qs)\n",

train and test data are concatenated in these calculations. I think it is wrong, and those should be separately calculated for each.