The data

The data for this dashboard come from the U.S. Census Bureau, available here. The data show state-to-state migration. I’ve saved the data in a text file called mig2015.txt (click here to download).

I organized these data (mainly deleting irrelevant columns and unmerging cells) in Excel. Let’s take a look:

library(data.table)
library(htmlTable)
library(tidyverse)

## Loading tidyverse: ggplot2
## Loading tidyverse: tibble
## Loading tidyverse: tidyr
## Loading tidyverse: readr
## Loading tidyverse: purrr
## Loading tidyverse: dplyr

## Conflicts with tidy packages ----------------------------------------------

## between():   dplyr, data.table
## filter():    dplyr, stats
## first():     dplyr, data.table
## lag():       dplyr, stats
## last():      dplyr, data.table
## transpose(): purrr, data.table

library(lubridate)

## 
## Attaching package: 'lubridate'

## The following objects are masked from 'package:data.table':
## 
##     hour, isoweek, mday, minute, month, quarter, second, wday,
##     week, yday, year

## The following object is masked from 'package:base':
## 
##     date

df<-fread("data/mig2015.txt")

htmlTable(head(df %>% map_if(is.Date, as.character,format="%b %d,%Y") %>% map_if(is.numeric, round,2) %>% as.data.frame() ,5), col.rgroup = c("none", "#F7F7F7"),caption="2015 State to State Migration Data",
          tfoot="Source: U.S. Census Bureau")

These data show migration across states based on the Census tables. The variable state.to is the destination state while state.from is the state of residence one year prior. I’ve excluded migration from outside the U.S. and from Puerto Rico and U.S. island territories. Also, migration within the same state is set equal to zero for this exercise (e.g. from Alabama to Alabama set equal to zero).

Getting the data to talk

Like in my guide on building a flexdashboard we are going to use crosstalk to get the graphs to respond to a filter select box. And like before, we’ll use plotly to make the graphs. We’ll also use DT to add an interactive data table.

Our plan is to be able to use a single filter box to filter two maps and a data table. The tricky part is that in one map we want to filter on state.to to show all the in migration by state, while on another map we want to filter on state.from to show out migration. We can do this by setting using ShareData with groups:

sd.from <- SharedData$new(df.from, ~state.from,group="state")
sd.to <- SharedData$new(df, ~state.to,group="state")

We use SharedData$new to create both sd.from and sd.new and use group="state" to indicate that these are part of a common group. Then, when we filter on state using the state group, we’ll filter both sd.from and sd.to.

Then we us the bs_cols function from crosstalk to set up a filter:

bscols(
  filter_select("state", "Select State", sd.to, ~state.to,multiple=F)
)

We only want to filter on one state at a time so we set multiple=FALSE.

Then, it’s just a matter of laying out the flexdashboard and setting up our widgets. For comparison, we embedded the original Tableau dashboard in our flexdashboard. How meta!

You can see a fullscreen version here.

You can get the code by clicking on the source button on the top right.