验证性因子分析

Question

我想使用一阶验证性因子分析（CFA）来评估模型中测量仪器的维度，可靠性和（方法内）收敛和判别有效性。然而，R-studio经常出现意外迹象和类似警告的警告......

我的构造看起来像这样

attach(TAM.Data)
PEU <- (PU04 + PEU01 + PEU02 + PEU03)
ATT <- (ATT01 + ATT02 + ATT03)
PE <-(ATT01 + ATT02 + ATT03)
PU <- (PU01 + PU02 + PU03)
INT <- (BI01 + BI02 + BI03)

CovMat <- cov(TAM.Matrix)

Model.TAM.Data <- specifyModel()
# First Factor = Perc. Ease of Use
PEU ->  PU04, a4, NA 
PEU ->  PEU01, a5, NA 
PEU ->  PEU02, a6, NA 
PEU ->  PEU03, a7, NA 

# Second Factor = Attitude 
ATT -> ATT01, a11,   NA 
ATT -> ATT02, a12,   NA 
ATT -> ATT03, a13,   NA 

# Third Factor = Perc. Enjoy.
PE -> PE01, a8,   NA 
PE -> PE02, a9,   NA 
PE -> PE03, a10,   NA 

# Fourth Factor = Perc. Usefulness 
PU ->  PU01, a1, NA
PU ->  PU02, a2, NA 
PU ->  PU03, a3, NA 

# Fifth Factor = Intention
INT -> BI01, lam14, NA 
INT -> BI02, lam15, NA
INT -> BI03, lam16, NA

# Relation between factors
# First relationship 
PA1 -> PA2
PA3 -> PA2
PA4 -> PA2

# Second relationship 
PA2 -> PA5

# Unique Variances
PU01 <-> PU01, e1,   NA 
PU02 <-> PU02, e2,   NA 
PU03 <-> PU03, e3,   NA 
PU04 <-> PU04, e4,   NA 
PEU01 <-> PEU01, e5,   NA 
PEU02 <-> PEU02, e6,   NA
PEU03 <-> PEU03, e7,   NA 
PE01 <-> PE01, e8,   NA 
PE02 <-> PE02, e9,   NA 
PE03 <-> PE03, e10,   NA 
ATT01 <-> ATT01, e11,   NA 
ATT02 <-> ATT02, e12,   NA
ATT03 <-> ATT03, e13,   NA 
BI01 <-> BI01, e14,   NA 
BI02 <-> BI02, e15,   NA 
BI03 <-> BI03, e16,   NA 

## Factor Variances fixed at 1 
PU <-> PU, NA, 1
PEU <-> PEU, NA, 1
PE <-> PE, NA, 1 
ATT <-> ATT, NA, 1 
INT <-> PA5, NA, 1 

警告我收到：

Error in matrix(unlist(strsplit(paths, "<->|<-|->")), ncol = 2, byrow = TRUE) : 
  'data' must be of a vector type, was 'NULL'