Questions tagged [vgam]
33 questions
0
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VGAM logit function overflows
VGAM version 0.93
> logit(1000, inverse=T)
[1] 0 # it should be 1
The problem is here:
exp(1000 - log1p(exp(1000)))
Here log1p(exp(1000)) becomes Inf
So the numerical method it uses doesn't handle large numbers, compared to plogis in base which…
colinfang
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R VGAM package: fit is poorer after adding the second explanatory vairable
Why does the fit get worse after adding the second explanatory variable?
require("VGAM")
df = data.frame(x = c(1,2,3,4,5,6,7,8,9,10), y = c(1,4,8,15,25,36,48,65,80,105), z = c(0,0,0,1,100,400,900,1600,1800,200) )
vgt1 = vgam(y~s(x, df=2),…
P.Escondido
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s() in mgcv doesn't work when VGAM package loaded
This
x <- rnorm(100)
y <- rnorm(100)
gam(y ~ s(x))
## Family: gaussian
## Link function: identity
## Formula:
## y ~ s(x)
## Estimated degrees of freedom:
## 1 total = 2
## GCV score: 0.8116283
breaks down, when VGAM package is loaded:…
adibender
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