/**
* Sets the surface this describes and regenerates all necessary mathematical information. If
* failure occurs no changes are made.
*
* @param f Polynomial in two variables representing the surface
* @param x First variable in f
* @param y Second variable in f
*/
public void setSurface(String f, String x, String y, Point2D basePoint, Point2D sheetsBase)
throws SetSurfaceException {
Algebraic newMonodromy;
HashSet<Point2D> newBranches;
List newDefiningSheets;
Point2D newBasePoint = basePoint;
String s;
try {
// First calculate the monodromy
s = "mono := central_monodromy(Record('f'=%s,'x'=%s, 'y'=%s), %s);";
s = String.format(s, f, x, y, maple.pointToString(basePoint));
newMonodromy = maple.evaluate(s);
List mapBranches = (List) maple.evaluate("map(x->x[1], mono[3]):");
newBranches = new HashSet<Point2D>();
for (int i = 1; i <= mapBranches.length(); ++i)
newBranches.add(maple.algToPoint(mapBranches.select(i)));
newBasePoint = maple.algToPoint(maple.evaluate("mono[1]:"));
} catch (MapleException e) {
throw new SetSurfaceException(
"Maple's monodromy calculation failed.\n" + "Surface change aborted.\n" + e);
}
// Then calculate our canonical sheet numbering at the requested base.
try {
List sheets = (List) maple.evaluate("mono[2]:");
newDefiningSheets =
maple.propagateSheets(getCurveString(f, x, y), sheets, basePoint, sheetsBase);
} catch (Exception e) {
throw new SetSurfaceException(
"Unable to translate maple's monodromy into unique definition "
+ "of sheets.\n"
+ "Does straight line path from base point to sheets base go too "
+ "close to a branch?\n"
+ e);
}
// Do this stuff at end so we can revert before if necessary
this.f = f;
this.x = x;
this.y = y;
this.sheetsBase = sheetsBase;
this.branches = newBranches;
this.monodromy = newMonodromy;
this.basePoint = newBasePoint;
this.definingSheets = newDefiningSheets;
fireSurfaceChangeEvent();
}
@Override
void precalcPermutations() {
cutsPermutation = new HashMap<Point2D, Algebraic>();
try {
maple.assignName("mono", surface.getMonodromy());
List perms = (List) maple.evaluate("mono[3]:");
for (int i = 1; i <= perms.length(); ++i) {
List pair = (List) perms.select(i);
Point2D branch = maple.algToPoint(pair.select(1));
cutsPermutation.put(branch, pair.select(2));
}
} catch (MapleException e) {
System.err.println("Unexpected format for monodromy");
System.err.println(e);
}
}
