Trendline_Automation

---
title: "trendline automation"
output: html_document
---

library(foreign); library(extrafont); library(dplyr);library(ggplot2);
library(RColorBrewer);library(tidyverse);library(scales);library(grid)
library(gtable);library(ggthemes);library(ggrepel)


#Define where you will save your plots
  results<-("yourfilepath/")
  
#Import your data 
  Trend_data<-read.csv(“C:/Example/Data.csv”)
  
#Add graphing function
  trend.graph <- function(Trend_data, na.rm = TRUE, ...)
  
#Create index and loop
  title_list <- unique(Trend_data$CHARTTITLE)
  for (i in seq_along(title_list)) {

#Create plot 
  plot <- 
  ggplot(subset(Trend_data, Trend_data $CHARTTITLE==title_list[i]), aes(x=YEAR, y=ESTIMATE, ymin=minmoe, ymax=maxmoe, 
  group=geography, color= geography)) +
  
#Aesthetics of line 
  geom_line(aes(colour=geography),size = 1.0) +  geom_point(size=1.5) +
  
#Aesthetics of margin of error as shaded area along the line
  geom_line(aes(colour=geography),size = 1.0) +  geom_point(size=1.5) +
  
#Aesthetics of number labels inside the trendline
  geom_text_repel(aes(label = formatC(ESTIMATE,format="f",digits=1, big.mark = ",",drop0trailing = TRUE)), 
  size=2.5,  segment.color = 'transparent', min.segment.length = 0, segment.size = 0, 
  point.padding = .3, nudge_x = 0, nudge_y = .1, direction = "y", famiy='Courier') +
  
#Define X and Y scales, add comma as thousand separator, limits and breaks. 
  scale_y_continuous(labels=function(ESTIMATE) paste0(comma(ESTIMATE)), expand = expand_scale(mult = .1, add=5),
  breaks=pretty_breaks(n=6),limits=c(min(Trend_data$minmoe[Trend_data$CHARTTITLE==title_list[i]]), 
  max(Trend_data$maxmoe[Trend_data$CHARTTITLE==title_list[i]]))) +
  
  scale_x_continuous(breaks= Trend_data$YEAR) +

#Specify colors of lines
  scale_color_manual(values=c("Geography1"="#1071B9", "Geography2"="#ED7927")) +
  scale_fill_manual(values=c("Geography1"="#1071B9", "Geography2"="#ED7927")) +

#Define legend position and font
  theme(legend.position="bottom", legend.title = element_blank(),legend.spacing.x = unit(.6, 'cm'),
  legend.text = element_text(family= 'Courier'),
  
#Define characteristics of background and add horizontal lines
  panel.grid.major.x = element_blank(), panel.grid.minor.y = element_blank(),
  panel.grid.major.y = element_line( size=.08, color="grey89"), panel.background = element_rect(fill = "white")) +  
  
#Add automated title, caption and subtitle
  ggtitle(title_list[i]) + labs( x="", y="",
  caption = str_wrap(paste0("Source: ",Trend_data$SOURCEID[Trend_data$CHARTTITLE==title_list[i]])),   
  subtitle = Trend_data$CHARTSUBTITLE[Trend_data$CHARTTITLE==title_list[i]]) + 

#Aesthetics of title and subtittle
  theme(plot.title=element_text (hjust = 0, face='bold', size=12, family='Courier',margin=margin(0,0,0,0))) +  theme(plot.subtitle = element_text(hjust=0, vjust=-.5,  family='Courier', size=10,margin=margin(0,0,20,0))) +
  theme(plot.caption = element_text(size=9, family='Courier')) +

#Aesthetics of X and Y labels and text labels
  theme(axis.title.y = element_text(family='Courier') )+
  theme(axis.title.x = element_text(family='Courier')) +
  theme(axis.text.x = element_text(family='Courier')) +
  theme(axis.text.y = element_text(family='Courier')) + + 
  theme (axis.line = element_line(size = 1, colour="gray70"),axis.text = element_text(colour = "black"))

#Save each trendlne individually using the title and adding the word "trendline_" immediately before the title.
   ggsave(plot, file=paste0(results, 'trendline_', title_list[i], ".png"))

#Print plots to screen
     print(plot)
     }
   }
   
 #Run Graphing Function
    trend.graph(Trend_data, ESTIMATE)