---
title: "Shadow path, line and step"
author: "Marc Menem"
date: "`r Sys.Date()`"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteIndexEntry{shadowtext introduction}
  %\VignetteDepends{ggplot2}
  %\usepackage[utf8]{inputenc}
---



```{r include=FALSE}
knitr::opts_chunk$set(warning = FALSE, message = TRUE)

library(ggplot2)
library(ggshadow)
```



## shadow line: `geom_shadowline()` 

The most simple use of `geom_shadowline()` is a simple replacement of `geom_line()` 

```{r fig.height=7, fig.width=7}
library(ggshadow)

ggplot(economics_long, aes(date, value01, colour = variable)) + geom_shadowline()

```

## varying line color

It is possible to draw lines with varying colors, and it is also possible to change the color, alpha and size of the shadow using `shadowcolor`, `shadowsize` and `shadowalpha`.

```{r fig.height=7, fig.width=7}
library(ggshadow)

ggplot(economics_long, aes(date, value01, group = variable, colour=value01, shadowcolor='grey', shadowalpha=0.5, shadowsize=5*(1-value01))) + geom_shadowline()

```

## Shadow point example: `geom_shadowpoint()` 

Example using `geom_shadowpoint()`.

```{r fig.height=7, fig.width=7}
ggplot(mtcars, aes(wt, mpg)) + geom_shadowpoint(aes( color = carb, shadowcolour = ifelse(vs == 1, 'red', 'blue') ))

```