# Intro

Variable is a way to to define inputs to the network, very much similar to the Input class in Keras. However, since we need to perform differentiation and other operations on the network, we cannot just use Input. Instead, we need to define the inputs of the network through Variable.

For scientific computations, a Variable has only a dimension of 1. Therefore, if you need to have a three-dimensional coordinate inputs, you need to define three variables:

from sciann import Variable

x = Variable('x')
y = Variable('y')
z = Variable('z')


This is precisely because we need to perform differentiation with respect to (x, y, z).

[source]

### Variable

sciann.functionals.variable.Variable(name=None, units=1, tensor=None, dtype=None)


Configures the Variable object for the network's input.

Arguments

• name: String. Required as derivatives work only with layer names.
• units: Int. Number of feature of input var.
• tensor: Tensorflow Tensor. Can be pass as the input path.
• dtype: data-type of the network parameters, can be ('float16', 'float32', 'float64').

Raises