DR Trend / Stats Report¶

The DR Trend / Stats report turns the per-point DR values of the selected measured lines into three longitudinal and distributional views:

a chainage chart per line, with a scatter of DR vs station plus a rolling-mean trend;
a zone statistics matrix that tabulates DR statistics per line and per polar zone (invert, walls, shoulders, crown);
per-zone histograms that show how DR is distributed inside each zone.

Each of the three sections can be switched on and off independently. The report is intended as the single document the project engineer prints when the question is “how is my DR behaving along this tunnel and where am I taking the hits?”.

Dialog¶

Open Reports → DR Trend / Stats… from the main menu.

Control	Effect
From / To	Chainage filter. Pre-filled with the alignment’s start and end chainage when the dialog opens; edit to narrow the band.
Line Definitions	Tick the measured lines.
Chainage chart	Emit the per-line scatter chart page(s). Default on.
Zone stats matrix	Emit the (lines × zones) statistics table. Default on.
Per-zone histograms	Emit one page per zone with mini-histograms. Default off.
Mode — Summary / Full	Full writes the raw-points XLSX sheet too (PDF is unaffected).
Format — PDF / XLSX

Zone assignment¶

The report classifies every measured point into one of six zones based on its polar angle inside the section. The angle convention is 0° = invert, 90° = right wall, 180° = crown, 270° = left wall, measured clockwise:

Zone	Angle range (deg)
Invert	345–360 and 0–15
Right Shoulder	15–75
Right Wall	75–105
Crown	105–255 (the top half from shoulder to shoulder)
Left Wall	255–285
Left Shoulder	285–345

This convention matches the per-sector compliance map in Clearance & Compliance (M2) and the heatmap axis labels in Longitudinal Analysis (M3), so the DR Trend report is directly comparable with the Analytics heatmaps.

Chainage chart¶

Produced when Chainage chart is ticked. One A4 page per measured line:

X-axis — chainage along the alignment, ticks drawn at sensible multiples of 10 m depending on the visible range.
Y-axis — signed DR in millimetres, centred on zero. Positive (over) is drawn green, negative (under) is drawn red.
Rolling mean — a blue line tracing the windowed mean of DR over a sliding window of adjacent points. Smooths short-scale noise so the systematic trend is visible even on a busy scatter.
Regression caption — a single line under the chart with the linear-regression slope, intercept, R², RMS and n for that line across the visible chainage band.

The caption values let the reviewer read off systematic bias at a glance: a non-zero slope means DR is drifting as the tunnel advances; a high R² says the drift is not just noise.

Zone statistics matrix¶

Produced when Zone stats matrix is ticked. One page with a matrix where:

rows are the selected measured line definitions;
columns are the six zones (Invert, L-Wall, R-Wall, L-Shoulder, R-Shoulder, Crown).

Every cell holds six numbers stacked vertically:

Stat	Meaning
n	Point count inside the zone.
mean	Arithmetic mean of DR.
σ	Sample standard deviation of DR.
min	Smallest (most negative) DR.
max	Largest (most positive) DR.
p95	95th percentile of abs(DR).

Zero-count cells are greyed out so the reader can see where survey coverage is thin.

Tip

The zone matrix is the fastest way to find systematic biases: a non-zero mean at the Crown with a comfortable σ means the crown is consistently over-excavated (or under-excavated) and is a candidate for a drilling-pattern correction.

Per-zone histograms¶

Produced when Per-zone histograms is ticked. One page per zone (up to six pages). Each page shows a 3×2 grid of mini-histograms — one tile per selected line, arranged three rows × two columns to fit an A4 portrait. Each histogram shares the same bin edges across tiles so that a reviewer can compare lines side-by-side.

The x-axis of a histogram is DR in millimetres, the y-axis is bin count. A zero-DR tick is drawn as a dashed vertical line for reference.

PDF layout¶

A4 portrait, 15 mm margin. The three logical sections (chart / matrix / histograms) are gated by their corresponding dialog checkbox and appear in that order.

XLSX layout¶

Summary — the zone statistics matrix as a flat (line × zone × stat) table.
Regression — one row per line definition with slope, intercept, R², RMS, n.
Points (Full mode only) — one row per measured point with its chainage, line, DR, zone and angle. Handy for downstream pivot tables.

Note

Both the chainage chart and the zone matrix use the same DR numbers as the Line vs Theoretical Report report, so the two documents always agree. If a section shows up as red in the chart, you can cross-reference its DR value in the Line vs Theoretical detail table for the same (section × line).