acplot.spad line 48 [edit on github]
Plot a NON-SINGULAR plane algebraic curve p(x, y) = 0.
makeSketch(p, x, y, a..b, c..d) creates an ACPLOT of the curve p = 0 in the region a <= x <= b, c <= y <= d. More specifically, 'makeSketch' plots a non-singular algebraic curve p = 0 in an rectangular region xMin <= x <= xMax, yMin <= y <= yMax. The user inputs makeSketch(p, x, y, xMin..xMax, yMin..yMax). Here p is a polynomial in the variables x and y with integer coefficients (p belongs to the domain Polynomial Integer). The case where p is a polynomial in only one of the variables is allowed. The variables x and y are input to specify the the coordinate axes. The horizontal axis is the x-axis and the vertical axis is the y-axis. The rational numbers xMin, ..., yMax specify the boundaries of the region in which the curve is to be plotted.
refine(p, x) is undocumented