Quantization method

[jacky4323]

I confused that why using the function 2^k-1 Instead of 2^k

take 2.34669849e-01 for example:

1. using 2^k-1 : weight_bit=2 the value is equal to 0.3333333,but actually 0.33 can't use two bits to represent
2. using 2^k : weight_bit=2 the value is equal to 0.25, it can use two bits (0.11) to represent

So why don't use 2^k? Did I make a mistake? thanks.

[yanghaojin]

Hi Jacky, you can try some examples with k=1, input r_i belongs to [0, 1] as e.g., please try these 3 values for r_i: 0.1, 0.4, 1.0, to check how many possible values of quantize(r_i, k) could get for both options.

BTW, the quantization part of BMXNet is still not fully finished, we are still working on some issue in the backward pass. Hopefully, we could update the project in the next month. Best HJ

[jacky4323]

I follow you're a suggestion to test,But If k larger than 1, it quantizes the vale using 2^k-1, and it can't be representable by k bits.

good news for update the project thanks!!

[jacky4323]

sorry,it's my mistake