51 lines
1.8 KiB
Python
51 lines
1.8 KiB
Python
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import numpy as np
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from fastapi import HTTPException
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from .config import MAX_COEFFICIENTS, NYQUIST_MARGIN
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def require_finite(value, name):
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if not np.isfinite(value):
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raise HTTPException(status_code=400, detail=f"{name} 必須是有限數值")
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return float(value)
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def validate_frequency(name, value, fs, *, below_nyquist=True):
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value = require_finite(value, name)
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if value <= 0:
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raise HTTPException(status_code=400, detail=f"{name} 必須大於 0")
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if below_nyquist and value >= (fs / 2) * NYQUIST_MARGIN:
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raise HTTPException(status_code=400, detail=f"{name} 必須小於 Nyquist 頻率 ({fs / 2:g} Hz)")
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return value
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def parse_coefficients(raw, name):
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try:
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values = [float(x.strip()) for x in raw.replace(",", " ").split() if x.strip()]
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except ValueError:
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raise HTTPException(status_code=400, detail=f"{name} 係數格式錯誤")
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return validate_coefficients(values, name)
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def validate_coefficients(values, name):
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if len(values) == 0:
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raise HTTPException(status_code=400, detail=f"{name} 係數不可為空")
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if len(values) > MAX_COEFFICIENTS:
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raise HTTPException(status_code=400, detail=f"{name} 係數最多 {MAX_COEFFICIENTS} 個")
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coeffs = np.asarray(values, dtype=float)
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if not np.all(np.isfinite(coeffs)):
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raise HTTPException(status_code=400, detail=f"{name} 係數必須都是有限數值")
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if name == "a" and np.isclose(coeffs[0], 0.0):
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raise HTTPException(status_code=400, detail="a[0] 不可為 0")
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return coeffs
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def normalize_coefficients(b_values, a_values):
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b_arr = validate_coefficients(b_values, "b")
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a_arr = validate_coefficients(a_values, "a")
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if not np.isclose(a_arr[0], 1.0):
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b_arr = b_arr / a_arr[0]
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a_arr = a_arr / a_arr[0]
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return b_arr, a_arr
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