In TensorFlow, the signature tf.sigmoid(x, name=None) computes sigmoid of x element-wise using y = 1 / (1 + exp(-x)) and returns a tensor with the same type x. Here is the parameter description:

• x: A tensor. This must be one of the following types: float32, float64, int32, complex64, int64, or qint32.
• name: A name for the operation (optional).