vignette_03_data_visualization.Rmd

---
title: "Visualization of Time Series Data"
author: "Alexander Häußer"
date: "`r format(Sys.Date(), '%B %Y')`"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{Visualization of Time Series Data}
  %\VignetteEngine{knitr::knitr}
  %\VignetteEncoding{UTF-8}
---

```{r setup, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  dev = "png",
  # fig.path = "figures/viz-",
  fig.height = 5,
  fig.width = 7
)
```

You can install the development version from [GitHub](https://github.com/) with:

``` r
# install.packages("devtools")
devtools::install_github("ahaeusser/tscv")
```

```{r packages, message = FALSE, warning = FALSE}
# Load relevant packages
library(tscv)
library(tidyverse)
library(tsibble)
```

```{r abbreviations, echo=FALSE, warning=FALSE, message=FALSE, results='hide'}
Sys.setlocale("LC_TIME", "C")
```

## Data

```{r data}
series_id = "bidding_zone"
value_id = "value"
index_id = "time"

context <- list(
  series_id = series_id,
  value_id = value_id,
  index_id = index_id
)

# Prepare data set
main_frame <- elec_price %>%
  filter(bidding_zone %in% c("DE", "FR", "NO1", "SE1"))

main_frame
```

## Line charts

```{r plot_line}

# Example 1 -------------------------------------------------------------------

main_frame %>%
  plot_line(
    x = time,
    y = value,
    color = bidding_zone,
    facet_var = bidding_zone,
    title = "Day-ahead Electricity Spot Price",
    subtitle = "2019-01-01 to 2020-12-31",
    xlab = "Time",
    ylab = "[EUR/MWh]",
    caption = "Data: ENTSO-E Transparency"
    )

# Example 2 -------------------------------------------------------------------

main_frame %>%
  plot_line(
    x = time,
    y = value,
    color = bidding_zone,
    title = "Day-ahead Electricity Spot Price",
    subtitle = "2019-01-01 to 2020-12-31",
    xlab = "Time",
    ylab = "[EUR/MWh]",
    caption = "Data: ENTSO-E Transparency"
    )

```

## Bar charts

```{r plot_bar}
# Estimate sample partial autocorrelation function
corr_pacf <- estimate_pacf(
  .data = main_frame,
  context = context,
  lag_max = 30
)

corr_pacf

# Visualize PACF as correlogram
corr_pacf %>%
  plot_bar(
    x = lag,
    y = value,
    color = sign,
    facet_var = bidding_zone,
    position = "dodge",
    title = "Sample autocorrelation function",
    xlab = "Lag",
    ylab = "Correlation",
    caption = "Data: ENTSO-E Transparency"
  )


```


## Distributions

### Histograms

```{r plot_histogram}
# Example 1 -------------------------------------------------------------------

main_frame %>%
  plot_histogram(
    x = value,
    color = bidding_zone,
    title = "Day-ahead Electricity Spot Price",
    xlab = "[EUR/MWh]",
    ylab = "Frequency",
    caption = "Data: ENTSO-E Transparency"
    )

# Example 2 -------------------------------------------------------------------

main_frame %>%
  plot_histogram(
    x = value,
    color = bidding_zone,
    facet_var = bidding_zone,
    facet_nrow = 1,
    title = "Day-ahead Electricity Spot Price",
    xlab = "[EUR/MWh]",
    ylab = "Frequency",
    caption = "Data: ENTSO-E Transparency"
    )
```

### Density

```{r plot_density}
# Example 1 -------------------------------------------------------------------
main_frame %>%
  plot_density(
    x = value,
    color = bidding_zone,
    title = "Day-ahead Electricity Spot Price",
    xlab = "[EUR/MWh]",
    ylab = "Density",
    caption = "Data: ENTSO-E Transparency"
    )

# Example 2 -------------------------------------------------------------------
main_frame %>%
  plot_density(
    x = value,
    color = bidding_zone,
    facet_var = bidding_zone,
    facet_nrow = 1,
    title = "Day-ahead Electricity Spot Price",
    xlab = "[EUR/MWh]",
    ylab = "Density",
    caption = "Data: ENTSO-E Transparency"
    )
```


### QQ-Plot

```{r plot_qq}
# Example 1 -------------------------------------------------------------------
main_frame %>%
  plot_qq(
    x = value,
    color = bidding_zone,
    title = "Day-ahead Electricity Spot Price",
    xlab = "Theoretical Quantile",
    ylab = "Sample Quantile",
    caption = "Data: ENTSO-E Transparency"
    )

# Example 2 -------------------------------------------------------------------
main_frame %>%
  plot_qq(
    x = value,
    color = bidding_zone,
    facet_var = bidding_zone,
    title = "Day-ahead Electricity Spot Price",
    xlab = "Theoretical Quantile",
    ylab = "Sample Quantile",
    caption = "Data: ENTSO-E Transparency"
    )
```