Documentation
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Overview ¶
Command nichols renders the chart a family of curves unlocks.
Like the other examples it is executed by a test, so it cannot silently stop compiling or stop producing a chart. And like examples/smith, its point is what is *not* here: there is no Nichols coord, no control-systems package and no new mark. A Nichols diagram is a geom.Line over two ordinary linear axes — the open-loop phase in degrees along X, the open-loop gain in decibels along Y — and what makes it a Nichols diagram is the grid printed underneath it, which is two geom.Locus layers.
The two families describe the *closed* loop T = L/(1+L) over a chart whose axes hold the open loop L. The M contours are the loci of constant |T| and are what the resonance peak is read off; the N contours are the loci of constant ∠T. Neither is at a value of either axis, which is why neither is furniture and both are annotations — see docs/adr/0050-locus-annotations.md.
Source Files