熔化命令后的错误信息，任何建议？
程序
df <- read.table(file.choose(), header=T, sep="\t")
library(ggplot2)
library(reshape2)
df1 <- melt(df,id.vars=1)
ggplot(df1,aes(x= factor(Flow.Path..m.),y=value,fill=variable))+
stat_boxplot(geom="errorbar",stat_params = list(width = 0.2),position=position_dodge(width=0.3))+
geom_boxplot(position=position_dodge(width=0.3),width=0.25) +
scale_fill_manual(values = c("grey", "black"))+ylab("Total Organic Carbon (TOC) mg/l")+xlab("Flow Path (m)")+labs(fill="",title=" Total Organic Carbon concentration along flow path and depths")+theme_classic()+theme(axis.title.y = element_text(angle=90))
熔化命令后的错误信息，任何建议？
Data
Flow.Path..m. Depth.0.52..m. Depth.0.46..m.
1 0.12 (T.Latifoli) 12,20 12,08
2 0.12 (T.Latifoli) 9,89 9,18
3 0.12 (T.Latifoli) 10,37 9,88
4 0.12 (T.Latifoli) 11,24 9,82
5 0.12 (T.Latifoli) 10,21 11,30
6 0.12 (T.Latifoli) 10,80 7,73
7 0.12 (T.Latifoli) 4,19 6,29
8 0.12 (T.Latifoli) 4,54 4,25
9 0.26 (T.Latifolia/P.Australi) 13,64 11,78
10 0.26 (T.Latifolia/P.Australi) 9,85 10,74
11 0.26 (T.Latifolia/P.Australi) 10,42 11,17
12 0.26 (T.Latifolia/P.Australi) 10,41 9,79
13 0.26 (T.Latifolia/P.Australi) 11,64 12,19
14 0.26 (T.Latifolia/P.Australi) 10,18 5,96
15 0.26 (T.Latifolia/P.Australi) 7,77 7,09
16 0.26 (T.Latifolia/P.Australi) 4,00 3,94
17 0.4 (P.Australis) 11,81 10,77
18 0.4 (P.Australis) 9,81 12,22
19 0.4 (P.Australis) 10,13 9,63
20 0.4 (P.Australis) 9,25 9,72
21 0.4 (P.Australis) 11,11 11,05
22 0.4 (P.Australis) 8,60 7,56
23 0.4 (P.Australis) 8,45 7,69
24 0.4 (P.Australis) 5,54 4,43
25 0.52 (P.Australis/J.Effusus) 10,10 9,51
26 0.52 (P.Australis/J.Effusus) 11,57 9,42
27 0.52 (P.Australis/J.Effusus) 10,45 10,16
28 0.52 (P.Australis/J.Effusus) 9,96 10,08
29 0.52 (P.Australis/J.Effusus) 12,00 11,56
30 0.52 (P.Australis/J.Effusus) 7,89 7,77
31 0.52 (P.Australis/J.Effusus) 6,15 8,48
32 0.52 (P.Australis/J.Effusus) 5,21 8,85