# petekIO — locked public API
> **This file is the contract.** The build must expose exactly these signatures
> (names, arguments, return types). Bodies are the implementer's; the *surface* is
> fixed. Changing a signature here requires sign-off. Rust is canonical; the
> Python (PyO3) section mirrors it. See `SPEC.md` for design/architecture.
Conventions: `Result<T> = std::result::Result<T, GeoError>`; arrays are
`ndarray` (`Array2<f64>` surfaces, `Array3<f32>` cubes); undefined = `NaN`.
---
## foundation
```rust
pub enum Unit { Feet, Metres }
pub struct Point3 { pub x: f64, pub y: f64, pub z: f64 }
pub struct BBox { pub xmin: f64, pub ymin: f64, pub xmax: f64, pub ymax: f64 }
/// Regular, rotatable areal lattice (IRAP/RMS model).
pub struct GridGeometry {
pub xori: f64, pub yori: f64, // origin (node 0,0)
pub xinc: f64, pub yinc: f64, // node spacing
pub ncol: usize, pub nrow: usize, // node counts (i along x, j along y)
pub rotation_deg: f64, // CCW of the I-axis from East
pub yflip: bool,
}
impl GridGeometry {
pub fn node_xy(&self, i: usize, j: usize) -> (f64, f64);
pub fn xy_to_ij(&self, x: f64, y: f64) -> Option<(f64, f64)>; // fractional node coords
pub fn bbox(&self) -> BBox;
}
#[derive(thiserror::Error, Debug)]
pub enum GeoError { /* Io, Parse, GeometryMismatch, NotFound, OutOfRange, Unit, ... */ }
```
## Stats — the universal aggregation result
```rust
pub struct Stats {
pub count: usize,
pub mean: f64, pub min: f64, pub max: f64, pub std: f64, pub sum: f64,
pub p10: f64, pub p50: f64, pub p90: f64,
}
impl Stats {
pub fn of(values: &[f64]) -> Stats; // NaN-skipping
pub fn weighted(values: &[f64], weights: &[f64]) -> Stats;
pub fn percentile(&self, p: f64) -> f64; // arbitrary p in [0,1]
}
```
## Surface
```rust
pub struct Surface { pub geom: GridGeometry /* values + attributes are private */ }
impl Surface {
// construction / IO
pub fn new(geom: GridGeometry, values: Array2<f64>) -> Result<Surface>;
pub fn constant(geom: GridGeometry, value: f64) -> Surface;
pub fn load_irap_classic(path: impl AsRef<Path>) -> Result<Surface>; // FIRST format
pub fn save_irap_classic(&self, path: impl AsRef<Path>) -> Result<()>;
// access
pub fn values(&self) -> &Array2<f64>;
pub fn sample(&self, x: f64, y: f64) -> Option<f64>; // bilinear, NaN-aware
pub fn attr(&self, name: &str) -> Option<&Array2<f64>>;
pub fn set_attr(&mut self, name: &str, values: Array2<f64>) -> Result<()>;
pub fn attr_names(&self) -> Vec<&str>;
pub fn as_attr_surface(&self, name: &str) -> Option<Surface>; // promote attr → ops
// element-wise math (on the primary values; return a new Surface)
pub fn ln(&self) -> Surface;
pub fn log10(&self) -> Surface;
pub fn exp(&self) -> Surface;
pub fn sqrt(&self) -> Surface;
pub fn abs(&self) -> Surface;
pub fn powf(&self, n: f64) -> Surface;
pub fn clamp_min(&self, lo: f64) -> Surface;
pub fn clamp(&self, lo: f64, hi: f64) -> Surface;
// surface ↔ surface (require equal geometry → GeometryMismatch otherwise)
pub fn plus(&self, other: &Surface) -> Result<Surface>;
pub fn minus(&self, other: &Surface) -> Result<Surface>;
pub fn times(&self, other: &Surface) -> Result<Surface>;
pub fn divided_by(&self, other: &Surface) -> Result<Surface>;
pub fn thickness(top: &Surface, base: &Surface, clamp_zero: bool) -> Result<Surface>;
// statistics / volumetrics
pub fn stats(&self) -> Stats;
pub fn area_below(&self, depth: f64) -> f64; // Σ cell-area where value ≤ depth
pub fn area_above(&self, depth: f64) -> f64;
pub fn volume_between(&self, base: &Surface) -> Result<f64>;
pub fn hypsometry(&self) -> Vec<(f64, f64)>; // (depth, area) curve
// resample (native)
pub fn resample(&self, target: &GridGeometry) -> Surface;
// cube extraction (Phase 3) → a surface attribute
pub fn slice_cube(&self, cube: &Cube, sampling: Sampling) -> Surface;
pub fn slice_cube_window(&self, cube: &Cube, above: f64, below: f64, agg: WindowAgg) -> Surface;
}
// operator overloads (scalar + surface), mirroring the methods
impl std::ops::Add<f64> for &Surface { type Output = Surface; /* + - * / */ }
impl std::ops::Sub<&Surface> for &Surface { type Output = Result<Surface>; }
```
## Wells: `Well` → `Sidetrack` → `Trajectory` (+ tops, logs)
```rust
pub struct Well { pub id: String, pub head: (f64, f64), pub kb: f64 /* sidetracks private */ }
impl Well {
pub fn new(id: impl Into<String>, head: (f64, f64), kb: f64) -> Well;
pub fn sidetrack(&self, label: &str) -> Option<&Sidetrack>;
pub fn sidetrack_mut(&mut self, label: &str) -> &mut Sidetrack; // creates if missing
pub fn main(&self) -> &Sidetrack; // label ""
pub fn sidetracks(&self) -> impl Iterator<Item = &Sidetrack>;
// delegate to main/active sidetrack:
pub fn xyz(&self, md: f64) -> Option<Point3>;
pub fn tvd(&self, md: f64) -> Option<f64>;
pub fn md_at_tvd(&self, tvd: f64) -> Option<f64>;
pub fn top(&self, name: &str) -> Option<Interval>;
pub fn log(&self, mnemonic: &str) -> Option<LogView>;
}
pub struct Sidetrack { pub label: String /* trajectories, logs, tops private */ }
impl Sidetrack {
pub fn add_trajectory(&mut self, input: TrajectoryInput) -> Result<&mut Trajectory>; // → active
pub fn set_active(&mut self, index: usize) -> Result<()>;
pub fn active(&self) -> &Trajectory;
pub fn trajectories(&self) -> &[Trajectory];
pub fn add_log(&mut self, log: Log);
pub fn add_tops(&mut self, tops: Vec<Top>);
pub fn xyz(&self, md: f64) -> Option<Point3>;
pub fn top(&self, name: &str) -> Option<Interval>;
pub fn log(&self, mnemonic: &str) -> Option<LogView>;
}
pub struct Station { pub md: f64, pub inc_deg: f64, pub azi_deg: f64 }
pub enum TrajectoryInput {
Xyz(Vec<Point3>),
MdIncAzi(Vec<Station>), // → minimum-curvature
Stations(Vec<Station>),
Hold { from: Station, to_md: f64 },
Steer { from: Station, build_per_100: f64, turn_per_100: f64, to_md: f64 },
}
pub struct Trajectory { /* normalized positioned path */ }
impl Trajectory {
pub fn xyz(&self, md: f64) -> Option<Point3>;
pub fn tvd(&self, md: f64) -> Option<f64>;
pub fn md_at_tvd(&self, tvd: f64) -> Option<f64>;
pub fn md_range(&self) -> (f64, f64);
}
pub struct Top { pub name: String, pub md: f64 }
pub struct Interval { pub name: String, pub top_md: f64, pub base_md: f64 } // base = next top / TD
impl Interval {
pub fn log(&self, mnemonic: &str) -> Option<LogView>; // log clipped to this interval
pub fn thickness_md(&self) -> f64;
}
pub struct Log { pub mnemonic: String, pub unit: String /* md, values private */ }
pub struct LogView<'a> { /* a possibly interval-clipped / filtered view */ }
impl<'a> LogView<'a> {
pub fn stats(&self) -> Stats; // the `well.brent.ntg` result
pub fn stats_weighted(&self, by: &LogView) -> Stats; // e.g. PV-weighted Sw
pub fn filter(&self, pred: impl Fn(f64) -> bool) -> LogView<'a>;
pub fn at_md(&self, md: f64) -> Option<f64>;
pub fn resample(&self, step: f64) -> Log;
pub fn values(&self) -> &[f64];
pub fn md(&self) -> &[f64];
}
```
## PointSet & PolygonSet (simpler)
```rust
pub struct PointSet { /* N×3 coords + named attribute columns */ }
impl PointSet {
pub fn load_csv(path: impl AsRef<Path>, x: &str, y: &str, z: &str) -> Result<PointSet>;
pub fn load_geojson(path: impl AsRef<Path>) -> Result<PointSet>;
pub fn load_irap_points(path: impl AsRef<Path>) -> Result<PointSet>;
pub fn len(&self) -> usize;
pub fn filter(&self, pred: impl Fn(Point3) -> bool) -> PointSet;
pub fn attr(&self, name: &str) -> Option<&[f64]>;
pub fn stats(&self, attr: &str) -> Option<Stats>;
pub fn bbox(&self) -> BBox;
pub fn nearest(&self, x: f64, y: f64) -> Option<usize>;
pub fn to_surface(&self, geom: GridGeometry, method: GridMethod) -> Result<Surface>;
}
pub enum GridMethod { Nearest, InverseDistance, MinimumCurvature }
pub struct PolygonSet { /* rings, optional Z */ }
impl PolygonSet {
pub fn load_geojson(path: impl AsRef<Path>) -> Result<PolygonSet>;
pub fn load_irap_polygons(path: impl AsRef<Path>) -> Result<PolygonSet>;
pub fn load_shapefile(path: impl AsRef<Path>) -> Result<PolygonSet>;
pub fn contains(&self, x: f64, y: f64) -> bool;
pub fn area(&self) -> f64;
pub fn bbox(&self) -> BBox;
pub fn clip(&self, surface: &Surface) -> Surface; // mask outside → NaN
}
```
## `GeoData` — the manager substrate
```rust
pub struct GeoData { pub unit: Unit /* surfaces, wells, points, polygons private */ }
impl GeoData {
pub fn new(unit: Unit) -> GeoData;
pub fn load_surface(&mut self, name: &str, path: impl AsRef<Path>) -> Result<&Surface>;
pub fn load_well(&mut self, id: &str, head: (f64,f64), kb: f64,
files: impl AsRef<Path>) -> Result<&Well>;
pub fn load_points(&mut self, name: &str, path: impl AsRef<Path>) -> Result<&PointSet>;
pub fn load_polygons(&mut self, name: &str, path: impl AsRef<Path>) -> Result<&PolygonSet>;
pub fn surface(&self, name: &str) -> Option<&Surface>;
pub fn well(&self, id: &str) -> Option<&Well>;
pub fn points(&self, name: &str) -> Option<&PointSet>;
pub fn polygons(&self, name: &str) -> Option<&PolygonSet>;
pub fn surfaces(&self) -> impl Iterator<Item = &Surface>;
pub fn wells(&self) -> WellsView;
}
pub struct WellsView<'a> { /* broadcastable, filterable */ }
impl<'a> WellsView<'a> {
pub fn filter(&self, pred: impl Fn(&Well) -> bool) -> WellsView<'a>;
pub fn iter(&self) -> impl Iterator<Item = &Well>;
pub fn tops(&self, name: &str) -> WellsView<'a>; // narrow to wells with that top
}
```
## Cube (Phase 3 — locked sketch)
```rust
pub enum Domain { Time, Depth }
pub enum PropertyKind { Amplitude, AcousticImpedance, VpVs, Porosity, Other(String) }
pub enum Sampling { Nearest, Trilinear }
pub enum WindowAgg { Min, Max, Rms, Mean }
pub struct CubeGeometry {
pub areal: GridGeometry,
pub zori: f64, pub zinc: f64, pub nz: usize,
pub ilines: Vec<i32>, pub xlines: Vec<i32>,
pub domain: Domain,
}
pub struct Cube { pub geom: CubeGeometry, pub property: PropertyKind, pub unit: String }
impl Cube {
pub fn load_segy(path: impl AsRef<Path>, iline_byte: u16, xline_byte: u16) -> Result<Cube>;
pub fn sample(&self, x: f64, y: f64, z: f64) -> Option<f32>;
pub fn inline(&self, label: i32) -> Option<Surface>;
pub fn zslice(&self, z: f64) -> Option<Surface>;
pub fn stats(&self) -> Stats;
pub fn resample(&self, target: &CubeGeometry) -> Cube;
}
```
---
## Python (PyO3) surface — the same contract, fluent
```python
import petekio
geo = petekio.GeoData(unit="ft")
geo.load_surface("top", "top.irap")
top, base = geo.surface("top"), geo.surface("base")
thick = (base - top).clamp_min(0) # operator overloads
trend = top.attr["seismic"].ln()
top.stats.p50 # Stats fields as attributes
top.area_below(8240)
ongrid = top.resample(grid_geom)
geo.load_well("15/9-A1", wellhead=(1200, 1500), kb=82, files="wells/A1/")
w = geo.well("15/9-A1")
w.xyz(2450) # interpolated position at MD
w.brent.ntg # -> Stats (dynamic: __getattr__ top → log)
w.brent.phie.mean
geo.wells.filter(field="Gullfaks").tops("Brent") # broadcast view
```
Python rules: `Stats` fields exposed as read-only attributes; operators (`+ - * /`)
on `Surface`; `surface.attr["name"]` indexed access; `well.<top>.<log>` resolves
via `__getattr__` (top interval → log → `Stats`). Bindings are thin: every method
delegates to the Rust API above.