---
title: "What is the gibble"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{What is the gibble}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)
```

```{r setup}
library(gibble)
```

The gibble package provides a basic unit of information about the structure of a
spatial data set. The key idea is of a *part* of spatial data, and the ways
these are arranged hierarchically in spatial formats.

If we consider a very simple polygon layer, as understood by the sf package the
structure is pretty simple. There are two objects (*features*), and the first of
those has two parts - here we call them **paths**, because they are represented
as a sequence of coordinates. 

```R
library(sf)
plot(minimal_mesh)
```

![minimal](../man/figures/minimal_mesh.png)


The `gibble()` function tells us about this structure

```{r gibble}
gibble(minimal_mesh)
```

and works on much more complicated data sets. 


```{r}
gibble(mpoly)
```

The `gibble()` function works for data in the formats used by
[sf](https://CRAN.r-project.org/package=sf),
[sp](https://CRAN.r-project.org/package=sp),
[trip](https://CRAN.r-project.org/package=trip), and
[silicate](https://CRAN.r-project.org/package=silicate). This eases the
development of tools that work with these formats, because they all have the
same underlying structure and we can find out the number of objects there are,
how many paths those objects have, and how many coordinates each path includes
without considering the way they are represented.