Create loops to write multiple graphs - r

Question

I want to use a loop in order to create multiple plots for different values of DPC. The data I have looks like:
df <- data.frame (c ("Results", "Capacity", "Power", "LDI","LDE", "LB", "PDC","D", CostPerkWh)
As output I would like multiple graphs with graphs for each unique value of PDC.
The following plot work:
plot1 <- ggplot(subset(df, df$PDC=='PDC0'),
aes(Capacity, CostPerkWh))+ geom_point()+geom_line()
plot2 <- ggplot(subset(df, df$PDC=='PDC0.25'),
aes(Capacity, CostPerkWh))+ geom_point()+geom_line()
plot3 <- ggplot(subset(df, df$PDC=='PDC0.5'),
aes(Capacity, CostPerkWh))+ geom_point()+geom_line()
plot4 <- ggplot(subset(df, df$PDC=='PDC0.75'),
aes(Capacity, CostPerkWh))+ geom_point()+geom_line()
plot5 <- ggplot(subset(df, df$PDC=='PDC1'),
aes(Capacity, CostPerkWh))+ geom_point()+geom_line()
All these plots work,however I would like to create a loop since I have a large amount of parameters and I found this example.
So I tried to implement it into my own model:
#plot data
StoreResults <- "/Users/IMA/Documents/Results/"
PDC.graph <- function(df, na.rm = TRUE, ...){
PDClist <- unique(df$PDC)
for (i in seq_along(PDClist)){
plot <-
ggplot(subset(df, df$PDC==PDClist[i]),
aes(Capacity, CostPerkWh)) + geom_point()+
ggtitle(paste(PDClist, 'PDC, Power \n', "Capacity \n", sep='')) +
geom_line()
print(plot)
#save plot as PNG
ggsave(plot, file= paste(StoreResults, '/projection_graphs/PDCgraph/',
PDClist[i], ".png", sep=''), scale=2)
}
}
The code does not give me an error message, but I don't see any graphs and nothing gets stored into the folder that is defined; how to resolve this? Or is there a better way to export many graph for different values of PDC?

Answer 1

Didn't you forget running the function you created?
This minimal version works for me:
df = iris
StoreResults <- "/Users/timfaber/Desktop"
PDC.graph <- function(df, na.rm = TRUE, ...){
PDClist <- unique(df$Species)
for (i in seq_along(PDClist)){
ggplot(subset(iris, df$Species==PDClist[i]),
aes(Sepal.Length, Sepal.Width)) + geom_point() +
ggtitle(paste(PDClist[i], 'PDC, Power \n', "Capacity \n", sep=''))
#save plot as PNG
ggsave(plot = last_plot(), file= paste(StoreResults, '/etc/',
PDClist[i], ".png", sep=''), scale=2)
}
}
PDC.Graph(df)