public override MatrixIndexer ExtractColumns(IList<int> columns)
{
SparseFloatVector[] r = new SparseFloatVector[vals.Length];
for (int i = 0; i < vals.Length; i++){
r[i] = (SparseFloatVector) vals[i].SubArray(columns);
}
return new SparseRowFloatMatrixIndexer{vals = r, ncolumns = columns.Count};
}
public override object Clone()
{
if (vals == null){
return new SparseRowFloatMatrixIndexer();
}
SparseFloatVector[] v = new SparseFloatVector[vals.Length];
for (int i = 0; i < v.Length; i++){
v[i] = (SparseFloatVector) vals[i].Clone();
}
return new SparseRowFloatMatrixIndexer{vals = v, ncolumns = ncolumns};
}
public SparseRowFloatMatrixIndexer(SparseFloatVector[] vals, int ncolumns)
{
this.vals = vals;
this.ncolumns = ncolumns;
}
public override void Set(float[,] value)
{
ncolumns = value.GetLength(1);
vals = new SparseFloatVector[value.GetLength(0)];
for (int i = 0; i < vals.Length; i++){
List<int> v = new List<int>();
for (int j = 0; j < ncolumns; j++){
if (value[i, j] == 0){
continue;
}
v.Add(j);
}
int[] v1 = v.ToArray();
float[] x = new float[v1.Length];
for (int j = 0; j < v1.Length; j++){
x[j] = value[i, v1[j]];
}
vals[i] = new SparseFloatVector(v1, x, ncolumns);
}
}
public override void Init(int nrows, int ncolumns1)
{
ncolumns = ncolumns1;
vals = new SparseFloatVector[nrows];
for (int i = 0; i < nrows; i++){
vals[i] = new SparseFloatVector(new int[0], new float[0], ncolumns);
}
}
internal static double SumSquaredDiffs(BoolArrayVector x, SparseFloatVector y)
{
double sum = 0;
int xlen = x.Length;
int ylen = y.indices.Length;
int i = 0;
int j = 0;
while (i < xlen && j < ylen){
if (i == y.indices[j]){
double d = y.values[j++];
if (x.values[i++]){
d -= 1;
}
sum += d*d;
} else if (i > y.indices[j]){
sum += y.values[j]*y.values[j];
++j;
} else{
if (x.values[i]){
sum += 1;
}
++i;
}
}
while (i < xlen){
if (x.values[i]){
sum += 1;
}
++i;
}
while (j < ylen){
sum += y.values[j]*y.values[j];
++j;
}
return sum;
}
internal static double SumSquaredDiffs(SparseFloatVector x, SparseFloatVector y)
{
double sum = 0;
int xlen = x.indices.Length;
int ylen = y.indices.Length;
int i = 0;
int j = 0;
while (i < xlen && j < ylen){
if (x.indices[i] == y.indices[j]){
double d = x.values[i++] - y.values[j++];
sum += d*d;
} else if (x.indices[i] > y.indices[j]){
sum += y.values[j]*y.values[j];
++j;
} else{
sum += x.values[i]*x.values[i];
++i;
}
}
while (i < xlen){
sum += x.values[i]*x.values[i];
++i;
}
while (j < ylen){
sum += y.values[j]*y.values[j];
++j;
}
return sum;
}
internal static double Dot(DoubleArrayVector x, SparseFloatVector y)
{
double sum = 0;
int xlen = x.Length;
int ylen = y.indices.Length;
int i = 0;
int j = 0;
while (i < xlen && j < ylen){
if (i == y.indices[j]){
sum += x.values[i++]*y.values[j++];
} else{
if (i > y.indices[j]){
++j;
} else{
++i;
}
}
}
return sum;
}
