Displaying 2 results from an estimated 2 matches for "rawmoments".
2012 Aug 03
1
SEM standardized path coefficients
...n2n, 1
df = read.csv('NDVI_lep_data.csv',header=T)
cor(df[,c('NDVI','All.S')])
yields:
NDVI All.S
NDVI 1.0000000 0.4156191
All.S 0.4156191 1.0000000
But, conducting an SEM yields:
sem.mod = specifyModel('SEM_NDVI_AllS_model.txt')
sem.mod.cov = rawMoments(~ NDVI + All.S, data = df)
sem.mod.cov = sem.mod.cov[-1,-1]
sem.mod.cov
NDVI All.S
NDVI 0.7820657 13.53573
All.S 13.5357259 245.71360
sem1 = sem(sem.mod, sem.mod.cov, N=29)
stdCoef(sem1)
n2S n2S 0.97643950 All.S <--- NDVI
n2n n2n 1.00000000 NDVI <--> NDV...
2013 Jul 22
1
Error with sem function df = -6
Hello all,
I have an issue where I am generating data and trying to confirm the
estimates using a sem. I keep getting an error about the degree of freedom
being negative "Error in sem.default(ram, S = S, N = N, raw = raw, data =
data, pattern.number = pattern.number, : The model has negative degrees of
freedom = -6"
Can someone explain this error or tell me what is wrong with my