Passing Functions to Reactives in R-Shiny - r

Question

Issue:
I'm interested in displaying three graphs in a shiny web app. I have written three functions to graph each type of plot for a specified range. The function's parameter takes a input parameter, region, and subsets the larger data.frame for that specified region and subsequently graphs it.
I'm having difficulty passing this function into an r-shiny reactive element.
Here is my function:
plot_30cumulative <- function(enter_region) {
subset <<- HPF[HPF$region == enter_region, ]
thirty_year_cumulative <<- ggplot(subset, aes(x=subset$date)) +
geom_line(aes(y = subset$BaseCumulative, color = "Base"), color = "green") +
geom_line(aes(y = subset$StressCumulative, color = "Adjusted"), color = "red", linetype = "dashed") +
theme_bw() +
scale_x_date(name = "",
date_labels = "%Y-%m-%d",
limits = as.Date(c("2014-02-15", "2044-02-15")),
breaks = seq(as.Date("2014-02-15"), as.Date("2044-02-15"), by = "1 year")) +
scale_y_continuous(name = "Cumulative Growth Rates",
breaks = seq(min(subset$StressCumulative),max(subset$BaseCumulative), .25),
limits = c(NA, 4), # Temporarily hard-coded for better visability.
labels = percent) +
theme(axis.text.x = element_text(angle = 90, hjust = 1)) +
ggtitle("Cumulative 30-Year Growth Rates")
What I Want in Shiny:
library(shiny)
#Define UI for dataset
ui <- fluidPage(
#App title ----
titlePanel("Home Price Forecasting under Stress Scenarios"),
sidebarLayout(
sidebarPanel(
#Input: Stress Path Function Parameters ----
#Input: Numeric entry for region to plot ----
numericInput(inputId = "region",
label = "Enter Region Number:",
value = "1",
min = 1,
max = 110)
),
# Main panel for displaying outputs ----
mainPanel(plotOutput(outputId = "ThYrC"),
plotOutput(outputId = "FiYrC"),
plotOutput(outputId = "FoYrQtr")
)
)
)
#Define server logic to summarize and view selected dataset ----
server <- function(input, output){
output$ThYrC <- renderPlot({reactive(plot_30cumulative(enter_region == input$region)}))
}
# Run the application ----
shinyApp(ui = ui, server = server)
Problem:
I can't seem to pass the function parameter, enter_region, to the reactive element by input$region == enter_region.
Any insight into this issue would be much appreciated!