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ovf/core/robust.py

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2025-09-15 11:41:55 -04:00
from models.basic import ModelBasic
from typing import List,Literal,Dict
import numpy as np
import random
from pydantic import BaseModel
from skrf import Network
from models.basic import ModelBasicDatasetUnit
class RobustParametricConfig(BaseModel):
n_poles: int
max_iter: int = 10
parameter_type: Literal["s","y","z"]
class RobustParametricModel:
def __init__(self,model:ModelBasic,config:RobustParametricConfig):
self.model = model
self.config = config
# 区分训练集和测试集
def _train_test_split(self,train_ratio:float=0.8,random_state:int=42):
random.seed(random_state)
dataset = self.model.results
random.shuffle(dataset)
train_size = int(len(dataset)*train_ratio)
self.train_set = dataset[:train_size]
self.test_set = dataset[train_size:]
return self.train_set, self.test_set
def first_iteration_step(self, datasets: List[ModelBasicDatasetUnit],
param_degree: int = 1):
'''
SK 迭代的第一步 (t=0) 对应论文公式 (3).
目标:
最小化 sum_{样本 n, 频点 f} | N^{(0)}(s_f, g_n) - H(s_f, g_n) |^2
t=0 阶段我们令 D^{(0)}(s,g)=1, 仅拟合分子:
N^{(0)}(s,g) = Σ_{pP} Σ_{vV} c_{p,v} * φ_freq_p(s) * φ_param_v(g)
因此是一个纯线性最小二乘:
H Σ_{p,v} c_{p,v} F[:,p] G[n,v]
:
F: (Nf, P) 频率正交(或原始)基列
G: (Ns, V) 参数多项式含常数基列
设计矩阵 A 大小 (Ns*Nf, P*V), A[(n*Nf + f), (p*V + v)] = F[f,p] * G[n,v]
输出:
self.first_iter_coeffs[(i,j)] = C_{p,v} (P × V) 每个端口对一套系数
self.freq_basis_F = F
self.param_basis_G = G
self.poles 初始极点 (供后续构造有理正交基 / SK 加权使用)
参数:
datasets: 训练用样本列表
param_degree: 参数多项式最大总次数 (默认 1 常数 + 线性)
注意:
这里使用简单频率基 [1, 1/(s-a_k)]未做 QR 正交化;
后续 SK 迭代 / 正交化可在第二步再进行
'''
assert len(datasets) > 0, "空数据集"
# ---------------- 收集频率与端口信息 ----------------
Ns = len(datasets)
freqs = datasets[0].freqs # 频率需要对齐
Nf = freqs.shape[0]
nports = self.model.info.nports
# ---------------- 构造初始极点 (对数分布 + 阻尼) ----------------
def _init_poles(n_poles: int):
fmin, fmax = freqs[0], freqs[-1]
if n_poles <= 0:
return np.array([], dtype=complex)
# 避免 0 Hz用第二个点或微小偏移
start_f = max(fmin if fmin > 0 else freqs[1] if Nf > 1 else 1.0e-3, 1e-12)
f_samples = np.logspace(np.log10(start_f), np.log10(fmax), n_poles)
sigma = 0.02 * 2 * np.pi * fmax # 固定阻尼,可放入 config
return -sigma + 1j * 2 * np.pi * f_samples
self.poles = _init_poles(self.config.n_poles)
s_vec = 1j * 2 * np.pi * freqs # (Nf,)
# ---------------- 频率基 F ----------------
# 列0: 常数 1, 后续列: 1/(s - a_k)
P = 1 + len(self.poles)
F = np.zeros((Nf, P), dtype=complex)
F[:, 0] = 1.0
for k, a in enumerate(self.poles, start=1):
F[:, k] = 1.0 / (s_vec - a)
self.freq_basis_F = F # (Nf, P)
# ---------------- 参数基 G ----------------
# 取出参数向量 g = [param1, param2, ...]
# 假设 datasets[i].parameters 为 dict
param_keys = list(datasets[0].parameters.keys())
d = len(param_keys)
# 构造参数矩阵 (Ns,d)
Pmat = np.zeros((Ns, d), dtype=float)
for i, unit in enumerate(datasets):
for j, k in enumerate(param_keys):
Pmat[i, j] = float(unit.parameters[k])
# 标准化
mean = Pmat.mean(axis=0)
std = Pmat.std(axis=0) + 1e-15
Xn = (Pmat - mean) / std
# 生成多项式指数 (总次数 <= param_degree)
def _gen_param_exps(dim, D):
exps = []
def rec(cur, idx, rem):
if idx == dim:
exps.append(tuple(cur)); return
for t in range(rem + 1):
cur.append(t); rec(cur, idx + 1, rem - t); cur.pop()
rec([], 0, D)
return exps
exps = _gen_param_exps(d, param_degree) # V_exps
V = len(exps)
G = np.zeros((Ns, V), dtype=float)
for vidx, e in enumerate(exps):
val = np.ones(Ns)
for j, p in enumerate(e):
if p:
val *= Xn[:, j] ** p
G[:, vidx] = val
self.param_basis_G = G # (Ns, V)
self.param_basis_meta = {
"keys": param_keys,
"mean": mean.tolist(),
"std": std.tolist(),
"exponents": exps,
"degree": param_degree
}
# ---------------- 构造设计矩阵 A (Kronecker) ----------------
# A shape: (Ns*Nf, P*V)
# 利用广播A_block[n,f,p,v] = F[f,p] * G[n,v]
A4 = np.einsum('fp,nv->nfpv', F, G) # (Ns, Nf, P, V)
A = A4.reshape(Ns * Nf, P * V)
# ---------------- 采集目标 H 数据 ----------------
# 对每个端口对 (i,j) 分别解一个向量 c_{p,v}
# 选择参数类型
param_type = self.config.parameter_type.lower()
valid_types = {"s", "y", "z"}
if param_type not in valid_types:
raise ValueError(f"parameter_type 必须在 {valid_types}")
# 预先载入全部 Network (避免重复 IO)
# H_data[(i,j)] -> (Ns,Nf) 复数
H_data = {}
for i_port in range(nports):
for j_port in range(nports):
H_mat = np.zeros((Ns, Nf), dtype=complex)
for n, unit in enumerate(datasets):
net: Network = unit.network
if param_type == "s":
sij = net.s[:, i_port, j_port]
elif param_type == "y":
sij = net.y[:, i_port, j_port]
else:
sij = net.z[:, i_port, j_port]
# 插值或对齐假设已完成
H_mat[n, :] = sij
H_data[(i_port, j_port)] = H_mat
# ---------------- 最小二乘求系数 ----------------
self.first_iter_coeffs = {}
# 可选: 预计算 A^+ (伪逆) 如果数据不巨大
# pinv = np.linalg.pinv(A)
for key, Hmat in H_data.items():
b = Hmat.reshape(Ns * Nf) # (Ns*Nf,)
# 解 x (长度 P*V)
x, *_ = np.linalg.lstsq(A, b, rcond=None)
C = x.reshape(P, V)
self.first_iter_coeffs[key] = C
# ---------------- 存储便于后续 SK 迭代使用 ----------------
self.meta_first_iter = {
"A_shape": A.shape,
"num_samples": Ns,
"num_freqs": Nf,
"freq_basis_dim": P,
"param_basis_dim": V
}
if getattr(self.config, "verbose", True):
print(f"[t=0] 线性最小二乘完成: A={A.shape}, 频率基P={P}, 参数基V={V}, 端口对={nports*nports}")
return self.first_iter_coeffs