package water.fvec;
import java.util.Arrays;
import water.*;
/**
* The scale/bias function, where data is in SIGNED bytes before scaling.
*/
public class C1SChunk extends Chunk {
static final int OFF=8+8;
public double _scale;
long _bias;
C1SChunk( byte[] bs, long bias, double scale ) { _mem=bs; _start = -1; _len = _mem.length-OFF;
_bias = bias; _scale = scale;
UDP.set8d(_mem,0,scale);
UDP.set8 (_mem,8,bias );
}
@Override protected final long at8_impl( int i ) {
long res = 0xFF&_mem[i+OFF];
if( res == C1Chunk._NA ) throw new IllegalArgumentException("at8 but value is missing");
return (long)((res+_bias)*_scale);
}
@Override protected final double atd_impl( int i ) {
long res = 0xFF&_mem[i+OFF];
return (res == C1Chunk._NA)?Double.NaN:(res+_bias)*_scale;
}
@Override protected final boolean isNA_impl( int i ) { return (0xFF&_mem[i+OFF]) == C1Chunk._NA; }
@Override boolean set_impl(int i, 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( !(0 <= res && res < 255) ) return false; // Out-o-range for a byte array
_mem[i+OFF] = (byte)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) { _mem[idx+OFF] = (byte)C1Chunk._NA; return true; }
@Override boolean hasFloat() { return _scale < 1.0 || _scale > Long.MAX_VALUE; }
@Override public AutoBuffer write(AutoBuffer bb) { return bb.putA1(_mem,_mem.length); }
@Override public C1SChunk read(AutoBuffer bb) {
_mem = bb.bufClose();
_start = -1;
_len = _mem.length-OFF;
_scale= UDP.get8d(_mem,0);
_bias = UDP.get8 (_mem,8);
return this;
}
@Override NewChunk inflate_impl(NewChunk nc) {
double dx = Math.log10(_scale);
assert PrettyPrint.fitsIntoInt(dx);
nc.set_len(nc.set_sparseLen(0));
final int len = len();
for( int i=0; i<len; i++ ) {
int res = 0xFF&_mem[i+OFF];
if( res == C1Chunk._NA ) nc.addNA();
else nc.addNum((res+_bias),(int)dx);
}
return nc;
}
public int pformat_len0() { return hasFloat() ? pformat_len0(_scale,3) : super.pformat_len0(); }
public String pformat0() { return hasFloat() ? "% 8.2e" : super.pformat0(); }
}