1
00:00:00,000 --> 00:00:03,150
So if you think back to
this diagram and you consider

2
00:00:03,150 --> 00:00:06,015
the input window to
be 20 values wide,

3
00:00:06,015 --> 00:00:07,770
then let's call them x0, x1,

4
00:00:07,770 --> 00:00:10,335
x2, etc, all the way up to x19.

5
00:00:10,335 --> 00:00:11,955
But let's be clear.

6
00:00:11,955 --> 00:00:13,110
That's not the value on

7
00:00:13,110 --> 00:00:17,010
the horizontal axis which is
commonly called the x-axis,

8
00:00:17,010 --> 00:00:19,185
it's the value of the time series

9
00:00:19,185 --> 00:00:21,675
at that point on
the horizontal axis.

10
00:00:21,675 --> 00:00:23,640
So the value at time t0,

11
00:00:23,640 --> 00:00:27,150
which is 20 steps before
the current value is called x0,

12
00:00:27,150 --> 00:00:30,225
and t1 is called x1, etc.

13
00:00:30,225 --> 00:00:32,399
Similarly, for the output,

14
00:00:32,399 --> 00:00:33,900
which we would then
consider to be

15
00:00:33,900 --> 00:00:37,300
the value at the current
time to be the y.