
water.fvec.C4SChunk Maven / Gradle / Ivy
package water.fvec;
import water.*;
import water.util.UnsafeUtils;
/**
* The scale/bias function, where data is in SIGNED bytes before scaling.
*/
public class C4SChunk extends Chunk {
static private final long _NA = Integer.MIN_VALUE;
static protected final int _OFF=8+8;
private transient double _scale;
public double scale() { return _scale; }
private transient long _bias;
@Override public boolean hasFloat(){ return _scale != (long)_scale; }
C4SChunk( byte[] bs, long bias, double scale ) { _mem=bs; _start = -1; set_len((_mem.length - _OFF) >> 2);
_bias = bias; _scale = scale;
UnsafeUtils.set8d(_mem,0,scale);
UnsafeUtils.set8 (_mem,8,bias );
}
@Override protected final long at8_impl( int i ) {
long res = UnsafeUtils.get4(_mem,(i<<2)+_OFF);
if( res == _NA ) throw new IllegalArgumentException("at8_abs but value is missing");
return (long)((res + _bias)*_scale);
}
@Override protected final double atd_impl( int i ) {
long res = UnsafeUtils.get4(_mem,(i<<2)+_OFF);
return (res == _NA)?Double.NaN:(res + _bias)*_scale;
}
@Override protected final boolean isNA_impl( int i ) { return UnsafeUtils.get4(_mem,(i<<2)+_OFF) == _NA; }
@Override boolean set_impl(int idx, long l) {
long res = (long)(l/_scale)-_bias; // Compressed value
double d = (res+_bias)*_scale; // Reverse it
if( (long)d != l ) return false; // Does not reverse cleanly?
if( !(Integer.MIN_VALUE < res && res <= Integer.MAX_VALUE) ) return false; // Out-o-range for a int array
UnsafeUtils.set4(_mem,(idx<<2)+_OFF,(int)res);
return true;
}
@Override boolean set_impl(int i, double d) { return false; }
@Override boolean set_impl(int i, float f ) { return false; }
@Override boolean setNA_impl(int idx) { UnsafeUtils.set4(_mem,(idx<<2)+_OFF,(int)_NA); return true; }
@Override public NewChunk inflate_impl(NewChunk nc) {
double dx = Math.log10(_scale);
assert water.util.PrettyPrint.fitsIntoInt(dx);
nc.set_sparseLen(0);
nc.set_len(0);
final int len = _len;
for( int i=0; i>2);
_scale= UnsafeUtils.get8d(_mem,0);
_bias = UnsafeUtils.get8 (_mem,8);
}
/**
* Dense bulk interface, fetch values from the given range
* @param vals
* @param from
* @param to
*/
@Override
public double [] getDoubles(double [] vals, int from, int to, double NA){
for(int i = from; i < to; ++i) {
long res = UnsafeUtils.get4(_mem,(i<<2)+_OFF);
vals[i-from] = res != C4Chunk._NA?(res + _bias)*_scale:NA;
}
return vals;
}
/**
* Dense bulk interface, fetch values from the given ids
* @param vals
* @param ids
*/
@Override
public double [] getDoubles(double [] vals, int [] ids){
int j = 0;
for(int i:ids) {
long res = UnsafeUtils.get4(_mem,(i<<2)+_OFF);
vals[j++] = res != C4Chunk._NA?(res + _bias)*_scale:Double.NaN;
}
return vals;
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy