library(ggplot2)
library(dplyr)
library(GGally)
library(scales)
library(memisc)
library(reshape)
library(gridExtra)

df<- read.csv("D:\\project4\\wineQualityReds.csv")
df
str(df)
summary(df)
df$X = factor(df$X)

# quality
summary(df$quality)
table(df$quality)

# assertion was correct here, so let's ensure the data frame semantically
# reflects that.
df$quality <- factor(df$quality, ordered = T)
str(df$quality)
# exploratory, quick histogram plots

grid.arrange(qplot(df$fixed.acidity),            
qplot(df$volatile.acidity),            
qplot(df$citric.acid),            
qplot(df$residual.sugar),            
qplot(df$chlorides),            
qplot(df$free.sulfur.dioxide),            
qplot(df$total.sulfur.dioxide),            
qplot(df$density),            
qplot(df$pH),            
qplot(df$sulphates),           
  qplot(df$alcohol),            
qplot(df$quality),            
ncol = 4)

Error: unexpected ')' in "ncol = 4)"
Error: could not find function "grid.arrange"