// if we don't have anything to filter, just use Dead Reckoning
public double[][] estimate() {
// use new velocity estimates to estimate xyzrpy
double[] Exyzrpy = LinAlg.scale(Vxyzrpy, T);
// convert back to RBT
double[][] Erbt = LinAlg.xyzrpyToMatrix(Exyzrpy);
// XXX there is a 2nd version of the function above which one is better
return Erbt;
}
public static void mixture() {
Graph g = new Graph();
int cnt = 5;
for (int i = 0; i < cnt; i++) {
GXYTNode gn = new GXYTNode();
gn.init = new double[] {i, 0, 0};
gn.state = LinAlg.copy(gn.init);
gn.truth = new double[3];
g.nodes.add(gn);
if (i > 0) {
double sig = 0.06;
// wheel slippage mode
GXYTEdge ge1 = new GXYTEdge();
ge1.z = new double[] {0, 0, 0};
ge1.P = LinAlg.diag(new double[] {sig, sig, sig});
ge1.nodes = new int[] {i - 1, i};
// nominal odometry
GXYTEdge ge2 = new GXYTEdge();
ge2.z = new double[] {1, 0, 0};
ge2.P = LinAlg.diag(new double[] {sig, sig, sig});
ge2.nodes = new int[] {i - 1, i};
GEdgeMixture ge = new GEdgeMixture(new GEdge[] {ge1, ge2}, new double[] {0.05, 0.95});
g.edges.add(ge);
}
}
if (true) {
GXYTEdge ge = new GXYTEdge();
ge.z = new double[] {cnt, 0, 0};
ge.P = LinAlg.diag(new double[] {0.1, 0.1, 0.1});
ge.nodes = new int[] {0, g.nodes.size() - 1};
g.edges.add(ge);
}
try {
g.write("mixture.graph");
} catch (IOException ex) {
System.out.println("ex: " + ex);
}
}
// weight A by alpha and B by 1-alpha if alpha == 1 then returns A
private double[] weightedSum(double[] A, double[] B, double[] W) {
assert ((A.length == B.length) && (A.length == W.length)) : "Warning!";
double[] C = new double[A.length];
for (int i = 0; i < A.length; i++) {
C[i] = (1 - W[i]) * A[i] + W[i] * B[i];
if (C[i] == Double.NaN) {
System.out.println("Warning generated NaN: T = " + T);
LinAlg.print(W);
}
}
return C;
}
// incorporate new information and return new estimate
public double[][] estimate(double[][] Urbt) {
// what rigid body transformation occured over the last frame
double[] DUxyzrpy = LinAlg.matrixToXyzrpy(Urbt);
// convert to velocity
double[] Uxyzrpy;
if (T != 0) {
Uxyzrpy = LinAlg.scale(DUxyzrpy, 1 / T);
} else {
Uxyzrpy = new double[6];
}
/*
System.out.println("Our observation velocity");
LinAlg.print(Uxyzrpy);
System.out.println("Our best estimate of velocity");
LinAlg.print(Vxyzrpy);
*/
// calculate relative weighting
double[] W = constructW(Uxyzrpy);
/*
System.out.println("Our weighting matrix");
LinAlg.print(W);
*/
// incorporatenew information
Vxyzrpy = weightedSum(Vxyzrpy, Uxyzrpy, W);
/*
System.out.println("After in corporating information");
LinAlg.print(Vxyzrpy);
*/
// use new velocity estimates to estimate xyzrpy
double[] Exyzrpy = LinAlg.scale(Vxyzrpy, T);
// convert back to RBT
double[][] Erbt = LinAlg.xyzrpyToMatrix(Exyzrpy);
// XXX there is a 2nd version of the function above which one is better
return Erbt;
}
public static void nomixture() {
Graph g = new Graph();
int cnt = 5;
double u = 0.95;
double sig = 0.1075;
for (int i = 0; i < cnt; i++) {
GXYTNode gn = new GXYTNode();
gn.init = new double[] {i, 0, 0};
gn.state = LinAlg.copy(gn.init);
g.nodes.add(gn);
if (i > 0) {
GXYTEdge ge = new GXYTEdge();
ge.z = new double[] {0.95, 0, 0};
ge.P = LinAlg.diag(new double[] {sig, sig, sig});
ge.nodes = new int[] {i - 1, i};
g.edges.add(ge);
}
}
if (true) {
GXYTEdge ge = new GXYTEdge();
ge.z = new double[] {0, 0, 0};
ge.P = LinAlg.diag(new double[] {0.1, 0.1, 0.1});
ge.nodes = new int[] {0, g.nodes.size() - 1};
g.edges.add(ge);
}
try {
g.write("nomixture.graph");
} catch (IOException ex) {
System.out.println("ex: " + ex);
}
}
public void read(StructureReader ins) throws IOException {
int ncomponents = ins.readInt();
components = new GEdge[ncomponents];
weights = new double[ncomponents];
for (int i = 0; i < components.length; i++) {
weights[i] = ins.readDouble();
String cls = ins.readString();
components[i] = (GEdge) ReflectUtil.createObject(cls);
ins.blockBegin();
components[i].read(ins);
ins.blockEnd();
}
attributes = Attributes.read(ins);
nodes = LinAlg.copy(components[0].nodes);
}
/** Components should all be of the same edge type. Weights should sum to 1. * */
public GEdgeMixture(GEdge components[], double weights[]) {
this.components = components;
this.weights = weights;
double total = 0;
assert (components.length == weights.length);
for (int i = 0; i < components.length; i++) {
total += weights[i];
assert (components[i].getClass().equals(components[0].getClass()));
assert (components[i].nodes.length == components[0].nodes.length);
for (int j = 0; j < components[0].nodes.length; j++) {
assert (components[i].nodes[j] == components[0].nodes[j]);
}
}
assert (total >= 0.99 && total <= 1.01);
this.nodes = LinAlg.copy(components[0].nodes);
}