In computer graphics, an input device that provides a scalar value.  在计算机图形学中,提供标量值(SV)的一种输入设备。  If you stored a scalar value like a number or string, then that is what will come back.  如果您存储的是数字或字符串等标量值(SV),那么将返回这些内容。  Reduction also applies over a list but typically reduces the list to a scalar value.  Reduce也适用于列表但是通常将列表缩减为标量值(SV)。