MetaboAnalystR 中的 2D PCA 得分图问题

如何解决MetaboAnalystR 中的 2D PCA 得分图问题

我无法从我的 mSet 对象获取 2D PCA 得分图。到目前为止，这是我的代码（我正在处理示例数据集并遵循小插图中给出的代码。

 mSet <- InitDataObjects("mspeak","stat",FALSE)
# Unzips the uploaded zip file/s,removes it and saves it as "upload"
UnzipUploadedFile("lcms_3col_peaks.zip","upload",F)
# Read peak lists/intensity files
(mSet <- Read.PeakList(mSet,"upload"))

##################################################################################
########################### Data Preprocessing ###################################
##################################################################################

### Peaks in NMR or MS peak lists that represent the same metabolite need to be combined 
mSet <- GroupPeakList(mSet,0.025,30.0)
# clean peak groups
(mSet <- SetPeakList.GroupValues(mSet))
# View message resulting from peak grouping 
mSet$dataSet$proc.msg

### Integrity Check: Is data suitable for subsequent analsysis
mSet <- SanityCheckData(mSet)
# to view any messages from sanity check:
mSet$dataSet$check.msg

#######################################################################################
########################## Data Processing ############################################
########################################################################################

########## Remove missing values

### Replace missing/zero values with a minimum positive value (can be perfomed before or after normalization)
mSet <- ReplaceMin(mSet)
# View messages collected during ReplaceMin()
mSet$msgSet$replace.msg

# Check if the sample size is too small (returns a 0 if the data passes the check)
mSet<-IsSmallSmplSize(mSet)

######### Nomalise

###Perform log transformation
mSet<-PreparePrenormData(mSet)
mSet <- Normalization(mSet,rowNorm = "NULL",transNorm = "LogNorm",scaleNorm = "AutoNorm",ref="NULL",ratio=FALSE,ratioNum=20)

# View feature normalization (sends these to working directory)
mSet<-PlotNormSummary(mSet,"feature_norm",format="png",dpi=300,width=0)
# View sample normalization
mSet<-PlotSampleNormSummary(mSet,"sample_norm",format="pdf",width=NA)

######### Filter

# 3 components of the FilterVariable function
(mSet <- FilterVariable(mSetObj = mSet,filter = "mad",# user specified method for filtering (median absolute deviaton)
                                qcFilter = F,# Filter variables based on QC samples (if true then filter = "none")
                                rsd = 30))       # Define relative standard deviation cut off (variables greater then this removed)

### Remove samples
# Check for outliers
PlotPCA2DScore(mSetObj = mSet,imgName = "2D PCA score plot",format = "png",dpi = 300,width = 0,pcx = 1,pcy = 2,reg = 0.95,show = 1,grey.scale = 0)

我出现了以下错误，但我不确定它是什么意思：

Error in var(cbind(pc1[inx],pc2[inx]),na.rm = T) : 'x' is NULL

有人可以帮我解决这个问题吗？谢谢