---
title: "Preparing Data for `radarchart`"
author: "Doug Ashton"
date: "`r Sys.Date()`"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{Preparing Data}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

The `radarchart` package expects data to be in a format whereby each row corresponds to an axis on the chart (or a `Label`) and each column is a set of scores. An example is the built in data set, `skills`.

```{r}
library(radarchart)
skills
```

In many cases your data will have a column for each axis, and each row is a set of observations. In the `skills` example we might build up a spreadsheet where each row is a person and each column a skill.

```{r}
skillsByName
```

In order to use this data set with `radarchart` we need to *rotate* it. This can be done with packages such as `tidyr`.

```{r, tidyR}
library(tidyr)
skillsByLabel <- gather(skillsByName, key=Label, value=Score, -Name) %>%
                   spread(key=Name, value=Score)
skillsByLabel
```

If you don't want to have a dependency on `tidyr` then you can do the same thing using a few lines of base `R` code.

```{r, baseR}
skillsByLabel <- as.data.frame(t(skillsByName[,-1]))
names(skillsByLabel) <- skillsByName$Name
skillsByLabel <- cbind(Label=row.names(skillsByLabel), skillsByLabel)
row.names(skillsByLabel) <- NULL
```

This rotated data set is now ready for use with `radarchart`.

```{r, eval=FALSE}
chartJSRadar(scores = skillsByLabel, maxScale = 10)
```