which page do i need?¶
find your question and follow the link. learn pages explain an idea from scratch, examples show one task on real data, workflows follow a whole problem from question to decision, and API pages list every argument.
new to geostatistics¶
| question | read |
|---|---|
| what does a sample represent, and why does its size matter? | learn 1. samples and support |
| how do i summarize a variable when the drilling is clustered? | learn 2. describing data |
| what is a variogram and how do i read one? | learn 3. spatial continuity |
| how does kriging choose its weights? | learn 4. kriging |
| why simulate when i can krige? | learn 5. simulation |
| how do i know a model is any good? | learn 6. checking a model |
| how is the library laid out? | guide how boitatá is organized |
| i want one pass from samples to a checked estimate. | quick tour |
drill holes, solids and grids¶
| question | read |
|---|---|
| i have a new drill hole database. is it clean? | workflow audit drill holes before modeling, then checking drill holes |
| my holes have overlapping or missing intervals. | checking drill holes (check_drillholes, fix_drillholes) |
| where is each sample in 3D? | desurveying drill holes |
| my assays have different lengths. | compositing |
| some collars or samples appear twice. | duplicates |
| an interval straddles a geological contact. | mesh-crossing interval splits |
| where does each hole run above cutoff? | runs and strip logs |
| i need a block model that covers my data. | block models, block model from extents |
| which blocks fall inside a solid, and by how much? | solids, workflow flag solid proportions |
| a thin solid gets the wrong volume on whole blocks. | sub-blocks, and the sub-blocking tutorial in workflows |
| my solid has holes, flipped faces or zero volume. | workflow find and fix degenerate solids |
| my rock-type model is full of isolated specks. | domain cleanup |
| i have a lease boundary or pit outline. | polygons |
| i need to read or write OBJ, STL, DXF, shapefiles or GeoTIFF. | mesh files, GIS formats |
| my block model does not fit in memory. | models larger than memory |
| i want to see holes and blocks in 3D or on sections. | 3D views, stepped sections, hole traces, sections with holes, live scene |
looking at the data¶
| question | read |
|---|---|
| the rich zones were drilled more densely. what is the true mean? | declustering, weight declustering |
| how do the statistics differ between domains? | statistics by domain |
| a few extreme assays dominate the mean. | top cuts, capping transform |
| many samples share one value, such as the detection limit. | despiking, censored normal score |
| is the boundary between two domains sharp or gradual? | contacts, soft-boundary statistics |
| do two sampling campaigns agree? | paired data |
| does the grade drift along strike or with depth? | swaths |
| how closely spaced is my drilling? | data spacing |
| how sure am i of the mean itself? | spatial bootstrap |
| how do my variables relate to each other? | correlations |
transforms¶
| question | read |
|---|---|
| i need gaussian scores for simulation or multigaussian kriging. | normal-score transform |
| my grades are parts of a whole and sum to 100 %. | compositional data |
| i have several correlated grades to decorrelate. | multivariate transforms |
| some samples lack one of the assays. | imputation, spatial imputation |
| my layer undulates between two surfaces. | unfolding |
variograms and search¶
| question | read |
|---|---|
| how do i compute a variogram along a direction? | experimental variograms |
| how do i fit a model to it? | variogram fitting |
| how large is the nugget effect? | downhole nugget, nugget inference |
| i have two or more variables to model together. | coregionalization |
| the direction of continuity changes across the deposit. | local variogram parameters, locally varying anisotropy |
| how big should my search be? | from variogram to search plan, search, search calibration |
estimating¶
| question | read |
|---|---|
| i want a first estimate of a grade. | ordinary kriging |
| i want inverse distance or nearest neighbor to compare against. | simple estimators |
| i need block averages, not point values. | block kriging |
| the grade has a trend. | universal kriging, external drift kriging |
| high grades spread too far. | high-grade restriction |
| a secondary variable is sampled more densely. | cokriging |
| i want the probability of exceeding a cutoff. | indicator kriging, multiple indicator kriging, multigaussian kriging |
| samples across a domain boundary should count a little. | soft boundaries |
categories and domains¶
| question | read |
|---|---|
| how do i name and color rock codes? | categories |
| how much did my domains change between two models? | domain change tables |
| what proportion of each rock type is in each block? | local proportions, categorical indicator kriging |
| i need possible layouts of the rock types. | sequential indicator simulation, plurigaussian simulation, grades in simulated rock types |
simulating and recoverable resources¶
| question | read |
|---|---|
| i want many equally likely grade maps. | sequential gaussian simulation, turning bands, direct sequential simulation |
| my grid is large and simulation is slow. | SGS along a shared path |
| i need simulated values at block size. | simulation at block support |
| several grades must stay correlated. | multivariate simulation, collocated cosimulation |
| geology looks like channels or lenses that a variogram cannot draw. | SNESIM and its multigrid, training images, image quilting |
| how much ore is above cutoff at the size of a mining block? | discrete gaussian model, uniform conditioning |
| i need a grade-tonnage curve and the metal it implies. | workflow grade-tonnage and metal change, result plots |
checking a model¶
| question | read |
|---|---|
| does my estimate honor the data? | model checks, section validation plates |
| are my variogram and search any good? | cross-validation |
| which blocks are well informed? | kriging diagnostics |
| do my realizations reproduce the histogram and variogram? | realization checks |
| how do i classify the resource? | classification |
| i have two estimates of one deposit. which differs where? | workflow compare two estimates |
surfaces, whole studies and files¶
| question | read |
|---|---|
| i want a grade shell or a contact surface from drill holes. | grade shells, contact surfaces, layered surfaces |
| i have measured orientations of the contact. | structural data |
| i want to see a full study from raw tables to a result. | case studies, such as from drill holes to a classified model |
| i want to save a variogram, a transform or a fitted estimator. | guide saving models, saving and loading, parquet |
| what does an argument do? | API: containers, drill holes, EDA, transforms, variography, estimation, simulation, modeling, datasets and plots |