ax1.scatter(cps[:, 0], cps[:, 1])

As an AI language model, I am not sure about the context of the code snippet you provided. However, based on my understanding of scatter plots, this code is probably plotting a scatter plot with x-coordinates from the first column of a 2D NumPy array called `cps` and y-coordinates from the second column of the same array.

The `ax1` variable is likely a reference to a subplot or axis created using Matplotlib library. The `scatter()` function is a method of this subplot/axis object that is used to create a scatter plot. The first argument to the `scatter()` function is the x-coordinate values and the second argument is the y-coordinate values.

Therefore, this code is probably creating a scatter plot from a 2D NumPy array `cps`.