uncertainty {APML} R Documentation

## Calculate the Uncertainty (95 percent confidence interval) of Risk Ratio Based on Threshold.

### Description

Calculate the uncertainty (95 percent confidence interval) of risk ratio with prediction from general models based on threshold.

### Usage

```uncertainty(x,y,th,ref=0)
```

### Arguments

 `x` A vector representing the risk factor. `y` A vector representing the outcome prediction probability. `th` Threshold for dividing the risk facot into two groups. `ref` Reference indicator. If 0, set the group lower than threshold as reference. Default:0

### Details

This is used to calculate the risk ratio, but not for odd ratio.

### Value

Uncertainty (95 percent confidence interval) of risk ratio.

### References

Díaz-Francés, E., Rubio, F.J. On the existence of a normal approximation to the distribution of the ratio of two independent normal random variables. Stat Papers 54, 309-C323 (2013).

### Examples

```
library(h2o)
data(iris)
attach(iris)
h2o.init()
hyper <- list(ntrees=c(2,3,5))
iris <- iris[1:100,c(5,1:4)]
idx <- sample(100,50)
traindata <- iris[idx,]
testdata <- iris[-idx,]
xcol <- names(iris)[2:5]
results <- APML(xcol=xcol,hyper=hyper,
traindata=traindata,testdata=testdata,
sort_by ='auc',distribution = 'bernoulli')
data <- as.h2o(iris)
pred<- h2o.predict(results\$bestmodel,newdata=data)
data <- h2o.cbind(data,pred)
data <- as.data.frame(data)
plots <- expl_rr(data,setosa~Sepal.Length,ref = 'mean')
uncertainty(data\$Sepal.Length,data\$setosa,plots\$threshold)
h2o.shutdown(prompt=FALSE)
Sys.sleep(2)
```

[Package APML version 0.0.3 Index]