Add demo for comparing written vs. spoken frequencies

Change-Id: I9416c8b199c64e55e10d40db0e475cf6de488b40
diff --git a/demo/writtenVsSpoken.R b/demo/writtenVsSpoken.R
new file mode 100644
index 0000000..6e63399
--- /dev/null
+++ b/demo/writtenVsSpoken.R
@@ -0,0 +1,13 @@
+# library(devtools)
+# install_github("KorAP/RKorAPClient")
+library(RKorAPClient)
+library(ggplot2)
+g <- new("KorAPConnection", verbose=T) %>%
+  frequencyQuery("sozusagen/i", vc=c("corpusSigle=FOLK", "corpusSigle!=FOLK")) %>%
+  ipm() %>%
+  mutate(corpus=c("FOLK", "DeReKo")) %>%
+  ggplot(aes(x = corpus, y = ipm, ymin = conf.low, ymax = conf.high))  +
+  geom_col() +
+  geom_errorbar(width = .3, alpha = .3) +
+  ggtitle("'sozusagen' in written (DeReKo) and spoken corpora (FOLK-excerpt)")
+print(g)