function _vectorNormMinusInfinity (x) {
      // norm(x, -Infinity) = min(abs(x))
      let ninf
      // skip zeros since abs(0) === 0
      x.forEach(function (value) {
        const v = abs(value)
        if (!ninf || smaller(v, ninf)) {
          ninf = v
        }
      }, true)
      return ninf || 0
    }
Calculate the minus infinity norm for a vector
@param {Matrix} x
@returns {number} Returns the norm
@private