Once you know that it's linear, you know that there's some way to describe this function as matrix multiplication.

一旦知道它是线性的 就知道有一些方法可以乘法来述这个。

You could even define this as matrix vector multiplication when you put the matrix on the left of the vector, like its a function.

甚至可以把它定义为向量乘法当把放在向量的左边 就像它是一个。

Specifically, since it's a function that goes from three dimensions to one dimension, there will be a one by three matrix that encodes this transformation.

具体来说 因为它是一个从三维到一维的 会有一个1×3的来编码这个变换。