public static Frame[] shuffleSplitFrame(
Frame fr, Key[] keys, final double ratios[], final long seed) {
// Sanity check the ratios
assert keys.length == ratios.length;
double sum = ratios[0];
for (int i = 1; i < ratios.length; i++) {
sum += ratios[i];
ratios[i] = sum;
}
assert water.util.MathUtils.equalsWithinOneSmallUlp(sum, 1.0);
// Do the split, into ratios.length groupings of NewChunks
final int ncols = fr.numCols();
MRTask mr =
new MRTask() {
@Override
public void map(Chunk cs[], NewChunk ncs[]) {
Random rng = new Random(seed * cs[0].cidx());
int nrows = cs[0]._len;
for (int i = 0; i < nrows; i++) {
double r = rng.nextDouble();
int x = 0; // Pick the NewChunk split
for (; x < ratios.length - 1; x++) if (r < ratios[x]) break;
x *= ncols;
// Helper string holder
ValueString vstr = new ValueString();
// Copy row to correct set of NewChunks
for (int j = 0; j < ncols; j++) {
byte colType = cs[j].vec().get_type();
switch (colType) {
case Vec.T_BAD:
break; /* NOP */
case Vec.T_STR:
ncs[x + j].addStr(cs[j], i);
break;
case Vec.T_UUID:
ncs[x + j].addUUID(cs[j], i);
break;
case Vec.T_NUM: /* fallthrough */
case Vec.T_ENUM:
case Vec.T_TIME:
ncs[x + j].addNum(cs[j].atd(i));
break;
default:
if (colType > Vec.T_TIME && colType <= Vec.T_TIMELAST)
ncs[x + j].addNum(cs[j].atd(i));
else throw new IllegalArgumentException("Unsupported vector type: " + colType);
break;
}
}
}
}
}.doAll(ncols * ratios.length, fr);
// Build output frames
Frame frames[] = new Frame[ratios.length];
Vec[] vecs = fr.vecs();
String[] names = fr.names();
Futures fs = new Futures();
for (int i = 0; i < ratios.length; i++) {
Vec[] nvecs = new Vec[ncols];
for (int c = 0; c < ncols; c++) {
mr.appendables()[i * ncols + c].setDomain(vecs[c].domain());
nvecs[c] = mr.appendables()[i * ncols + c].close(fs);
}
frames[i] = new Frame(keys[i], fr.names(), nvecs);
DKV.put(frames[i], fs);
}
fs.blockForPending();
return frames;
}
@Override
public void init() {
super.init();
createEnums();
}