fix and rename vignette

README.md

@@ -34,9 +34,11 @@ library(econpanel)
 data(planetmoney)
 ```
 
-The vignette[^1] illustrates several ways to explore the data.
+The vignette "exploration" illustrates some questions and answers pursuable through these datasets. Access it like this:
 
-[^1]: I'm having some trouble on my own machines building the vignettes when i install the package. Sorry about that. Feel free to point out where my problem might be.
+```r
+vignette(topic = "exploration", package = "econpanel")
+```
 
 ## Acknowledgments
 

vignettes/introduction.rmd → vignettes/exploration.rmd

@@ -23,9 +23,6 @@ knitr::opts_chunk$set(collapse=TRUE,
 library(econpanel)
 library(dplyr)
 library(ggtern)
-#library(ggrepel) # ggrepel is not yet permitted in ggtern
-library(likert)
-library(ggbiplot)
 ```
 
 ## Planet Money's campaign season survey
@@ -41,17 +38,19 @@ The economics communication team at [Planet Money](http:https://www.npr.org/sections/m
 knitr::kable(planetmoney %>% select(-Brief) %>% distinct)
 ```
 
-The opinions are far from uniform, and it's not obvious how to gauge how "far" those on one proposal are from those on another. One way to line up the survey questions according to their responses is a Likert plot, produced here using [the likert package by Jason Bryer](http:https://jason.bryer.org/likert/):
+The opinions are far from uniform, and it's not obvious how to gauge how "far" those on one proposal are from those on another. One way to line up the survey questions according to their responses is a Likert plot, produced here using [the likert package by Jason Bryer](http:https://jason.bryer.org/likert/) (*warning: the likert and ggtern packages both depend on ggplot2 and do not play well together*):
 
 ```{r Likert plot of Planet Money votes, fig.height=4}
 n <- unique(rowSums(planetmoney[, c("Bad", "Debatable", "Good")]))
 stopifnot(length(n) == 1)
 planetmoney_likert <-
- likert(summary = planetmoney[, c("Brief", "Bad", "Debatable", "Good")] %>%
- transmute(Item = Brief,
- Bad = Bad * 100 / n,
- Debatable = Debatable * 100 / n,
- Good = Good * 100 / n))
+ likert::likert(
+ summary = planetmoney[, c("Brief", "Bad", "Debatable", "Good")] %>%
+ transmute(Item = Brief,
+ Bad = Bad * 100 / n,
+ Debatable = Debatable * 100 / n,
+ Good = Good * 100 / n)
+ )
 plot(planetmoney_likert)
 ```
 
@@ -113,7 +112,7 @@ levs <- c("Strongly Disagree", "Disagree",
 for (j in 1:ncol(igm_matrix))
  igm_matrix[[j]] <- factor(igm_matrix[[j]], levels = levs)
 # Likertify
-igm_likert <- likert(as.data.frame(igm_matrix))
+igm_likert <- likert::likert(as.data.frame(igm_matrix))
 plot(igm_likert)
 ```
 
@@ -145,8 +144,8 @@ The `vote_numbers` part assigns numerical values to the votes; purely by persona
 ```{r principal components biplot of IGM panelists, fig.height=7}
 # construct a PCA biplot
 stack_names <- gsub("^([^,]*), ([A-Z])[^,]*$", "\\2. \\1", rownames(igm_pca$x))
-ggbiplot(igm_pca, obs.scale = 1, var.scale = 1,
- labels = stack_names, labels.size = 4, alpha = 1) +
+ggbiplot::ggbiplot(igm_pca, obs.scale = 1, var.scale = 1,
+  labels = stack_names, labels.size = 4, alpha = 1) +
  theme_bw()
 ```