---
title: "A quick start to the `spectacles` package"
author: "Pierre Roudier"
date: "`r Sys.Date()`"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{A quick start to the spectacles package}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r setup, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  fig.align = 'center',
  fig.height = 5,
  fig.width = 5
)
```

```{r libs}
library(spectacles)
```

# Converting data to a `SpectraDataFrame`

```{r australia}
data("australia")
class(australia)
big.head(australia)
```

```{r conversion}
spectra(australia) <- sr_no ~ ... ~ 350:2500
summary(australia)
```

# Accessing the different elements of the `SpectraDataFrame` object

## General information about the `SpectraDataFrame` 

`nrow` returns the number of samples in the object:

```{r}
nrow(australia)
```

`ncol` returns the number of attributes in the data slot of the object, and returns `NULL` if the object does not have associated data:

```{r}
ncol(australia)
```

`length` returns the number of wavelengths in the object:

```{r}
length(australia)
```

`dim` returns a numeric vector of these three dimensions:

```{r}
dim(australia)
```

## Subsetting

```{r}
sub <- australia[1:5,]
summary(sub)
```

## Accessing specific properties of Spectra objects

Specific functions are available to access the various properties of Spectra objects:

`ids` is returning a vector containing the IDs of the object. It has a `as.vector` option. When turned to `FALSE`, the function returns a `data.frame` instead of a vector. This is particularly useful to retrieve the original column name of the IDs: 

```{r}
# Just printing the first 5
ids(australia)[1:5]
```

`wl` is returning the wavelengths of the object in a numeric vector:

```{r}
# Just printing the first 10
wl(australia)[1:10]
```

`spectra` is returning the spectra matrix:


```{r}
s <- spectra(australia)
class(s)
dim(s)
big.head(s)
```

`wl_units` is returning the wavelength units:


```{r}
wl_units(australia)
```

`features` is returning associated data into a `data.frame`:

```{r}
df <- features(australia)
class(df)
head(df)
```

# Basic plotting 

```{r plot-1}
plot(australia)
```

```{r plot-2}
plot(australia, col = "royalblue")
```