Ggplot 2 "Error: discrete value set for continuous scaling"

Question

I would like to ask how to fix this error described in the title of the question? Just yesterday, the code worked fine, and the charting program created the desired chart. Woke up today and tried to add some features, and then received an error message.

Any clues why and how to fix it?

thanks

Data Channel: Data.csv

code:

# Loading data morStats <- read.csv(file = "F:/Purdue University/RA_Position/PhD_ResearchandDissert/PhD_Draft/DissertationDraft/MoroccoCGE-CC_Stats.csv", header=TRUE, sep=",", na.string="NA", dec=".", strip.white=TRUE) # Transferring the .csv data into data frames moroccostats <- as.data.frame(morStats) # Changing the data in the dataframe to "as.numeric" moroccostats[3:38] <- sapply(moroccostats[3:38],as.numeric) moroccostats <- droplevels(moroccostats) # reorder moroccostats <- transform(moroccostats,year=factor(year,levels=unique(year))) # Load packages library(reshape2) library(ggplot2) library(lattice) library(grid) library(plyr) library(gridExtra) library(scales) #---------------------------------------------------------------------- # Figure 1: Evolution of population (in absolute terms) 1960-2050 #--------------------------------------------------------------------- #_Code_Begin... moroccostats.f <- melt(moroccostats, id="year") morstats.pop <- moroccostats.f[moroccostats.f$variable %in% c("pop_t","pop_ur","pop_ru"),] Figure1 <- ggplot(data=morstats.pop,aes(x=factor(year), y=value,colour=variable)) Figure1 + geom_line(aes(group=factor(variable)),size=1) + geom_point() + scale_colour_manual("Population",labels=c("Total","Urban","Rural"),values = c("black","red","blue")) + labs(y="Population (in 1000)") + theme(axis.text.x = element_text(colour = 'black', angle = 90, size = 13, hjust = 1, vjust = 0.5),axis.title.x = element_blank()) + theme(axis.text.y = element_text(colour = 'black', size = 13, hjust = 0.5, vjust = 0.5), axis.title.y = element_text(size = 10, hjust = 0.5, vjust = 0.2, face = 'bold')) + scale_x_discrete(breaks = seq(1960, 2050, by=2)) + scale_y_continuous(breaks = seq(0, 42000, by=5000)) #_Code_End... 

Answer 1

moroccostats has a structure

 > str(moroccostats) 'data.frame': 91 obs. of 38 variables: $ year : Factor w/ 91 levels "1960","1961",..: 1 2 3 4 5 6 7 8 9 10 ... $ periodframe : Factor w/ 4 levels "0","Phase 1 (1965 to 1985)",..: 1 1 1 1 1 2 2 2 2 2 ... $ pop_t : num 11635 11897 12177 12473 12785 ... $ pop_ur : num 3395 3547 3703 3862 4026 ... ... 

When you swim to get the year moroccostats.f , you will get

 > str(moroccostats.f) 'data.frame': 3367 obs. of 3 variables: $ year : Factor w/ 91 levels "1960","1961",..: 1 2 3 4 5 6 7 8 9 10 ... $ variable: Factor w/ 37 levels "periodframe",..: 1 1 1 1 1 1 1 1 1 1 ... $ value : chr "0" "0" "0" "0" ... 

Note that value is a symbol because periodframe was a factor. I assume that the periodframe changed from a number to a character (bit of phase 1 (1965-1985)).

Since you only draw the columns pop_t and pop_ur and pop_ru , pull them out before melting

 morstats.pop <- melt(moroccostats[c("year","pop_t","pop_ur","pop_ru")], id="year") 

then you don’t need to worry about enforcing other types of fees for inappropriate columns.