判定语照方向接末尾连续期数、辛普森的结构变化只说一遍（复核 R14、R21）：趋势末尾连续同向的期数和趋势同向时接「，已连续 3 周下降」，反向时接「，但最近已连续 3 周上升」，不再出现「呈下降趋势……已连续 3 周上升」。比率拆解判在结构变化上（mix_driven）时正文已经说了结构变化、点了那一段，辛普森那一句只说「各段的退款率大多在下降，整体却上升」；别的判定照旧带上哪一段占比从多少变到多少

backend/app/analysis/decompose.py

@@ -577,9 +577,11 @@ def _ratio_result(env: Env, params: dict[str, Any], used: list[str], segs: list[
         against = sum(((by_key[x.key][0] + by_key[x.key][1]) / 2 for x in eligible
                        if (by_key[x.key][3] - by_key[x.key][2]) * sign < 0), Fraction(0))
         if weight > 0 and against / weight >= SIMPSON_SHARE:
+            # 判在结构变化上（mix_driven）时判定语正文已经说了结构变化、点了这一段，附带说明只说各段和整体反着变
             star = max(live, key=lambda x: sign * by_key[x.key][4])
             caveats.append(ph.caveat("simpson", ph.simpson_text(label, delta > 0, ph.key_text(star.key),
-                                                                by_key[star.key][0], by_key[star.key][1])))
+                                                                by_key[star.key][0], by_key[star.key][1],
+                                                                shift=code != "mix_driven")))
     if small:
         caveats.append(ph.caveat("small_denominator", ph.small_denominator_text(
             [ph.key_text(x.key) for x in small], den_label, int(env.settings["min_denominator"]))))

backend/app/analysis/phrases.py

@@ -301,13 +301,16 @@ def offset_text(delta_total: Any, gross_up: Any, gross_down: Any) -> str:
     return f"下降的段合计 {down}，上升的段合计 {up}，互相抵消了一部分"
 
 
-def simpson_text(label: str, overall_up: bool, subject: str, w_base: Any, w_target: Any) -> str:
-    """辛普森：各段的比率大多和整体反着变，整体的变化来自结构。"""
+def simpson_text(label: str, overall_up: bool, subject: str, w_base: Any, w_target: Any, *, shift: bool = True) -> str:
+    """辛普森：各段的比率大多和整体反着变，整体的变化来自结构。判定语正文已经说了结构变化、点了那一段（mix_driven）时
+    shift 为假，只说各段和整体反着变，结构变化不说第二遍。"""
     seg = "上升" if not overall_up else "下降"
     whole = "上升" if overall_up else "下降"
+    head = say("各段的", label, f"大多在{seg}，整体却{whole}")
+    if not shift:
+        return head
     move = "升" if _q(w_target) > _q(w_base) else "降"
-    return say(f"各段的", label, f"大多在{seg}，整体却{whole}：变化来自结构，", subject,
-               f"占比从 {pct(w_base, signed=False)} {move}到 {pct(w_target, signed=False)}")
+    return say(head, "：变化来自结构，", subject, f"占比从 {pct(w_base, signed=False)} {move}到 {pct(w_target, signed=False)}")
 
 
 def small_denominator_text(segments: Sequence[str], denominator: str, minimum: int) -> str:
@@ -478,13 +481,15 @@ def baseline_flat_phrase(verdict: str, label: str, current: str, n: int, unit: s
 
 def trend_phrase(verdict: str, label: str, n: int, unit: str, per: str, slope: str | None,
                  run: tuple[int, str] | None) -> str:
+    """趋势。末尾连续同向的期数（run）和趋势同向时接「，已连续 3 周下降」，反向时接「，但最近已连续 3 周上升」。"""
     if verdict == "no_trend":
         return say(f"过去 {n} {unit}", label, "没有明显的上升或下降趋势")
     word = "上升" if verdict == "rising" else "下降"
     text = say(f"过去 {n} {unit}", label, f"呈{word}趋势") + (f"（每{per}约 {slope}）" if slope else "")
     if run is not None:
         length, direction = run
-        text += f"，已连续 {length} {unit}{'上升' if direction == 'up' else '下降'}"
+        same = (direction == "up") == (verdict == "rising")
+        text += f"，{'' if same else '但最近'}已连续 {length} {unit}{'上升' if direction == 'up' else '下降'}"
     return text
 
 

backend/tests/test_analysis_decompose.py

@@ -301,9 +301,12 @@ async def test_simpson_each_channel_improves_but_the_mix_makes_the_whole_worse()
     rows = [["线上", "W41", 50, 500], ["线上", "W42", 90, 1000], ["线下", "W41", 10, 1000], ["线下", "W42", 4, 500]]
     result = await ratio(rows, label="退款率")
     assert result["verdict"] == {"code": "mix_driven", "subjects": [["线上"]], "direction": "up"}
-    assert result["phrase"].startswith("退款率上升 2.3 个百分点（4.0% 到 6.3%），主要来自结构变化：线上占比从 33.3% 到 66.7%")
+    # 结构变化只说一遍：正文说了结构变化、点了线上，辛普森那一句只说各段和整体反着变
+    assert result["phrase"] == ("退款率上升 2.3 个百分点（4.0% 到 6.3%），主要来自结构变化：线上占比从 33.3% 到 66.7%；"
+                                "各段的退款率大多在下降，整体却上升")
     simpson = next(c for c in result["caveats"] if c["code"] == "simpson")
-    assert simpson["text"] == "各段的退款率大多在下降，整体却上升：变化来自结构，线上占比从 33.3% 升到 66.7%"
+    assert simpson["text"] == "各段的退款率大多在下降，整体却上升"
+    assert result["phrase"].count("结构") == 1
     values = result["values"]
     assert Fraction(values["mix_total"]) + Fraction(values["rate_total"]) == pytest.approx(Fraction(values["delta"]))
     assert result["table"]["columns"][:5] == ["channel", "n_base", "n_target", "d_base", "d_target"]

backend/tests/test_analysis_phrases.py

@@ -141,3 +141,18 @@ def test_criteria_are_written_with_the_actual_thresholds():
     assert "3 倍以上算明显超出" in ph.criterion_baseline(DEFAULTS, 12, "周")
     assert "小于 0.05" in ph.criterion_trend(DEFAULTS, 10, "周")
     assert "Fisher" in ph.criterion_differ(DEFAULTS, "rate") and "Welch" in ph.criterion_differ(DEFAULTS, "mean")
+
+
+
+def test_the_run_at_the_end_of_a_trend_says_whether_it_goes_the_same_way():
+    assert ph.trend_phrase("falling", "销售额", 10, "周", "周", "-2.0%", (3, "down")) == \
+        "过去 10 周销售额呈下降趋势（每周约 -2.0%），已连续 3 周下降"
+    assert ph.trend_phrase("falling", "销售额", 10, "周", "周", "-2.0%", (3, "up")) == \
+        "过去 10 周销售额呈下降趋势（每周约 -2.0%），但最近已连续 3 周上升"
+    assert ph.trend_phrase("rising", "订单数", 8, "个月", "月", None, (4, "down")) == \
+        "过去 8 个月订单数呈上升趋势，但最近已连续 4 个月下降"
+
+
+def test_simpson_says_the_shift_only_when_the_phrase_does_not():
+    assert ph.simpson_text("退款率", True, "线上", 0.3, 0.5) == "各段的退款率大多在下降，整体却上升：变化来自结构，线上占比从 30.0% 升到 50.0%"
+    assert ph.simpson_text("退款率", True, "线上", 0.3, 0.5, shift=False) == "各段的退款率大多在下降，整体却上升"

backend/tests/test_analysis_series.py

@@ -313,3 +313,9 @@ async def test_sequence_periods_say_completeness_cannot_be_checked():
     result = await baseline(rows, basis="level")
     assert {"code": "comparability", "text": "没能核对本期的数据是否到齐（期次不是日期，不知道是哪几天）"} \
         in result["caveats"]
+
+
+async def test_a_falling_trend_whose_last_weeks_rise_says_but():
+    falling = await trend(weeks([200, 196, 190, 188, 181, 176, 170, 165, 160, 162, 165, 168]))
+    assert falling["verdict"]["code"] == "falling" and falling["values"]["run_direction"] == "up"
+    assert falling["phrase"].endswith("，但最近已连续 3 周上升")