Element-wise sign operation

Symbolic element-wise sign operation for LazyTensor objects.

Usage

# S3 method for LazyTensor
sign(x)

Arguments

x

a LazyTensor, a ComplexLazyTensor, a vector of numeric values, or a scalar value.

Value

An object of class LazyTensor.

Details

If x is a LazyTensor, sign(x) returns a LazyTensor that encodes, symbolically, the element-wise sign of x, i.e. $$\text{sign}(x) = \left\{ \begin{array}{rcl} 0 & \text{if } & x = 0\\ -1 & \text{if } & x < 0\\ 1 & \text{if } & x > 0 \end{array}\right.$$

See also

sign()

Author

Chloe Serre-Combe, Amelie Vernay

Examples

if (FALSE) {
x <- matrix(runif(150 * 3), 150, 3) # arbitrary R matrix, 150 rows, 3 columns
x_i <- LazyTensor(x, index = 'i')   # creating LazyTensor from matrix x, 
                                    # indexed by 'i'
Sign_x <- sign(x_i)                 # symbolic matrix, 150 rows and 3 columns
}