public double dot(Vector y) {
checkSize(y);
double ret = 0;
for (VectorEntry e : this) ret += e.get() * y.get(e.index());
return ret;
}
public Vector scale(double alpha) {
if (alpha == 0) return zero();
else if (alpha == 1) return this;
for (VectorEntry e : this) e.set(alpha * e.get());
return this;
}
public Vector add(double alpha, Vector y) {
checkSize(y);
if (alpha == 0) return this;
for (VectorEntry e : y) add(e.index(), alpha * e.get());
return this;
}
public Vector set(double alpha, Vector y) {
checkSize(y);
if (alpha == 0) return zero();
zero();
for (VectorEntry e : y) set(e.index(), alpha * e.get());
return this;
}
/**
* Check whether an entry is set.
*
* @param entry The entry.
* @return {@code true} if the entry is set in this vector.
* @throws IllegalArgumentException if the entry is not from this vector or another vector sharing
* the same key domain. Only vectors and their side channels share key domains for the
* purposes of this check.
*/
public boolean isSet(VectorEntry entry) {
final SparseVector evec = entry.getVector();
final int eind = entry.getIndex();
if (evec == null) {
throw new IllegalArgumentException("entry is not associated with a vector");
} else if (!keys.isCompatibleWith(evec.keys)) {
throw new IllegalArgumentException("entry does not have safe key domain");
}
assert entry.getKey() == keys.getKey(eind);
return keys.indexIsActive(eind);
}
@Override
public String toString() {
// Output into coordinate format. Indices start from 1 instead of 0
Formatter out = new Formatter();
out.format("%10d %19d\n", size, Matrices.cardinality(this));
for (VectorEntry e : this)
if (e.get() != 0) out.format("%10d % .12e\n", e.index() + 1, e.get());
return out.toString();
}
protected double norm2_robust() {
double scale = 0, ssq = 1;
for (VectorEntry e : this) {
double xval = e.get();
if (xval != 0) {
double absxi = Math.abs(xval);
if (scale < absxi) {
ssq = 1 + ssq * Math.pow(scale / absxi, 2);
scale = absxi;
} else ssq = ssq + Math.pow(absxi / scale, 2);
}
}
return scale * Math.sqrt(ssq);
}
/**
* Creates a new square matrix whose number of rows and columns match the dimensionality of the
* given vector. It also places the values of the vector on the diagonal of the matrix.
*
* @param diagonal The vector of diagonal values.
* @return A new, square matrix with the diagonal elements equal to the elements of the given
* vector.
*/
public MatrixType createDiagonal(final Vectorizable diagonal) {
final Vector vector = diagonal.convertToVector();
final int dimensionality = vector.getDimensionality();
// Create the matrix.
final MatrixType result = this.createMatrix(dimensionality, dimensionality);
// Set the diagonal values.
for (VectorEntry entry : vector) {
final int i = entry.getIndex();
result.setElement(i, i, entry.getValue());
}
return result;
}
/**
* Get the value for the entry's key.
*
* @param entry A {@code VectorEntry} with the key to look up
* @return the key's value
* @throws IllegalArgumentException if the entry is unset, or if it is not from this vector or
* another vector sharing the same key domain. Only vectors and their side channels share key
* domains for the purposes of this check.
*/
public double get(VectorEntry entry) {
final SparseVector evec = entry.getVector();
final int eind = entry.getIndex();
if (evec == null) {
throw new IllegalArgumentException("entry is not associated with a vector");
} else if (!evec.keys.isCompatibleWith(keys)) {
throw new IllegalArgumentException("entry does not have safe key domain");
}
assert entry.getKey() == keys.getKey(eind);
if (keys.indexIsActive(eind)) {
return values[eind];
} else {
throw new IllegalArgumentException("Key " + entry.getKey() + " is not set");
}
}
@Override
@Nonnull
public VectorEntry next() {
int pos = iter.nextInt();
boolean isSet = state == VectorEntry.State.SET || keys.indexIsActive(pos);
double v = isSet ? values[pos] : Double.NaN;
entry.set(pos, keys.getKey(pos), v, isSet);
return entry;
}
/**
* Standardize the matrix entries by row- or column-wise z-scores (z=(x-u)/sigma)
*
* @param isByRow standardize by row if true; otherwise by column
*/
public void standardize(boolean isByRow) {
int iters = isByRow ? numRows : numColumns;
for (int iter = 0; iter < iters; iter++) {
SparseVector vec = isByRow ? row(iter) : column(iter);
if (vec.getCount() > 0) {
double[] data = vec.getData();
double mu = Stats.mean(data);
double sigma = Stats.sd(data, mu);
for (VectorEntry ve : vec) {
int idx = ve.index();
double val = ve.get();
double z = (val - mu) / sigma;
if (isByRow) this.set(iter, idx, z);
else this.set(idx, iter, z);
}
}
}
}
/**
* Count the common keys between two vectors.
*
* @param o The other vector.
* @return The number of keys appearing in both this and the other vector.
*/
public int countCommonKeys(SparseVector o) {
int count = 0;
Iterator<VectorEntry> i1 = fastIterator();
Iterator<VectorEntry> i2 = o.fastIterator();
VectorEntry e1 = i1.hasNext() ? i1.next() : null;
VectorEntry e2 = i2.hasNext() ? i2.next() : null;
while (e1 != null && e2 != null) {
final long k1 = e1.getKey();
final long k2 = e2.getKey();
if (k1 < k2) {
e1 = i1.hasNext() ? i1.next() : null;
} else if (k2 < k1) {
e2 = i2.hasNext() ? i2.next() : null;
} else {
count += 1;
e1 = i1.hasNext() ? i1.next() : null;
e2 = i2.hasNext() ? i2.next() : null;
}
}
return count;
}
/**
* Compute the dot product between two vectors.
*
* @param o The other vector.
* @return The dot (inner) product between this vector and {@var o}.
*/
public double dot(SparseVector o) {
double dot = 0;
Iterator<VectorEntry> i1 = fastIterator();
Iterator<VectorEntry> i2 = o.fastIterator();
VectorEntry e1 = i1.hasNext() ? i1.next() : null;
VectorEntry e2 = i2.hasNext() ? i2.next() : null;
while (e1 != null && e2 != null) {
final long k1 = e1.getKey();
final long k2 = e2.getKey();
if (k1 < k2) {
e1 = i1.hasNext() ? i1.next() : null;
} else if (k2 < k1) {
e2 = i2.hasNext() ? i2.next() : null;
} else {
dot += e1.getValue() * e2.getValue();
e1 = i1.hasNext() ? i1.next() : null;
e2 = i2.hasNext() ? i2.next() : null;
}
}
return dot;
}
@Override
public Entry<Double> next() {
VectorEntry e = delegate.next();
return new BasicEntry<>(e.getKey(), (Double) e.getValue());
}
protected double norm1() {
double sum = 0;
for (VectorEntry e : this) sum += Math.abs(e.get());
return sum;
}
protected double norm2() {
double norm = 0;
for (VectorEntry e : this) norm += e.get() * e.get();
return Math.sqrt(norm);
}
protected double normInf() {
double max = 0;
for (VectorEntry e : this) max = Math.max(Math.abs(e.get()), max);
return max;
}
@Override
public Long getKey() {
return entry.getKey();
}
@Override
public Double getValue() {
return entry.getValue();
}
public Vector zero() {
for (VectorEntry e : this) e.set(0);
return this;
}
