plot: Changing numpoints scales the contents on the x-axis

See the post below:

Changing the numpoints attribute of plot~ scales its contents on the x-axis. SO when viewing a filter response graph, the response seems to change by modifying a parameter that's supposed to alter the display precision (right?).

After changing the number of points, re-setting the x- and y- grid and -labels shifts the grid lines too.

Also: the enumvals attribute is listed in the reference, but sending it to plot~ gives an error: plot~: doesn't understand "enumvals"

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As a side note, I stumbled across this behaviour because I wanted to plot the frequency response of a filter with its center frequency set to low settings. Below 1000 Hz, the plotted line gets very coarse (a Butterworth 2nd order band-pass at 90-110 Hz is displayed as a pyramid with only a few points, and increasing the number of points scales the graph as explained before).