Real-valued CKKS scaling factor at a modulus-chain level

Returns cryptoParams->GetScalingFactorReal(level) — the double-valued scaling factor at the given level of the CKKS modulus chain. Meaningful only for CKKS contexts; BFV/BGV contexts return the default field value (effectively 1.0).

Usage

get_scaling_factor_real(cc, ...)

Arguments

cc

A CryptoContext.

...

Method-specific arguments. The CryptoContext method accepts level (integer level in the RNS modulus chain, default 0L — the top of the chain = the scaling factor at fresh encryption time).

Value

Numeric scalar.

Details

Used by ckks_scaling_factor_bits() (which takes log2 of the level-0 value to recover the bit size originally set via set_scaling_mod_size()) and by the Stage 2 form of fhe_ckks_tolerance().