Visualize asct per diagnosis per year

This adds ggplots to visualize the number of ascts per diagnosis per
year in various methods:

* Histogram
* Density plot
* Frequency plot
* Scatter plot

visualize.R

@@ -16,7 +16,39 @@ sma_hist_asct_year <- function() {
 	ggplot(data, aes(x = asct_year)) + geom_histogram(binwidth = 1)
 }
 
+i_dx_year_data <- function() {
+	return(data.frame(asct_year = secmal$asct_year, dx = secmal$diagnosis))
+}
+
+sma_hist_dx_year <- function() {
+	data <- i_dx_year_data()
+	ggplot(data, aes(x = asct_year, colour = dx, fill = dx)) +
+		geom_histogram(binwidth = 1)
+}
+
+sma_dens_dx_year <- function() {
+	data <- i_dx_year_data()
+	ggplot(data, aes(x = asct_year, colour = dx, fill = dx)) +
+		geom_density(alpha = 0.5)
+}
+
+sma_freq_dx_year <- function() {
+	data <- i_dx_year_data()
+	ggplot(data, aes(x = asct_year, colour = dx)) +
+		geom_freqpoly(binwidth = 1)
+}
+
+sma_jitt_dx_year <- function() {
+	data <- i_dx_year_data()
+	ggplot(data, aes(x = asct_year, y = dx, colour = dx, fill = dx)) +
+		geom_jitter(width = 0.4, height = 0.2)
+}
+
 sma_plot_file_hist <- function() {
 	sma_plot_file("hist_asct_age.png", png, sma_hist_asct_age)
 	sma_plot_file("hist_asct_year.png", png, sma_hist_asct_year)
+	sma_plot_file("dx_year_hist.png", png, sma_hist_dx_year)
+	sma_plot_file("dx_year_dens.png", png, sma_dens_dx_year)
+	sma_plot_file("dx_year_freq.png", png, sma_freq_dx_year)
+	sma_plot_file("dx_year_jitt.png", png, sma_jitt_dx_year)
 }