TestSmallFloatpublic class TestSmallFloat extends TestCase
| Methods Summary |
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| static float | orig_byteToFloat(byte b)
if (b == 0) // zero is a special case
return 0.0f;
int mantissa = b & 7;
int exponent = (b >> 3) & 31;
int bits = ((exponent+(63-15)) << 24) | (mantissa << 21);
return Float.intBitsToFloat(bits);
| | static byte | orig_floatToByte(float f)
if (f < 0.0f) // round negatives up to zero
f = 0.0f;
if (f == 0.0f) // zero is a special case
return 0;
int bits = Float.floatToIntBits(f); // parse float into parts
int mantissa = (bits & 0xffffff) >> 21;
int exponent = (((bits >> 24) & 0x7f) - 63) + 15;
if (exponent > 31) { // overflow: use max value
exponent = 31;
mantissa = 7;
}
if (exponent < 0) { // underflow: use min value
exponent = 0;
mantissa = 1;
}
return (byte)((exponent << 3) | mantissa); // pack into a byte
| | public void | testByteToFloat()
for (int i=0; i<256; i++) {
float f1 = orig_byteToFloat((byte)i);
float f2 = SmallFloat.byteToFloat((byte)i, 3,15);
float f3 = SmallFloat.byte315ToFloat((byte)i);
assertEquals(f1,f2,0.0);
assertEquals(f2,f3,0.0);
float f4 = SmallFloat.byteToFloat((byte)i,5,2);
float f5 = SmallFloat.byte52ToFloat((byte)i);
assertEquals(f4,f5,0.0);
}
| | public void | testFloatToByte()
Random rand = new Random(0);
// up iterations for more exhaustive test after changing something
for (int i=0; i<100000; i++) {
float f = Float.intBitsToFloat(rand.nextInt());
if (f!=f) continue; // skip NaN
byte b1 = orig_floatToByte(f);
byte b2 = SmallFloat.floatToByte(f,3,15);
byte b3 = SmallFloat.floatToByte315(f);
assertEquals(b1,b2);
assertEquals(b2,b3);
byte b4 = SmallFloat.floatToByte(f,5,2);
byte b5 = SmallFloat.floatToByte52(f);
assertEquals(b4,b5);
}
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