[R] Sensitivity and Specificity

Michael Dewey ||@t@ @end|ng |rom dewey@myzen@co@uk
Mon Oct 24 17:45:47 CEST 2022


Rather hard to know without seeing what output you expected and what 
error message you got if any but did you mean to summarise your variable 
predict before doing anything with it?

Michael

On 24/10/2022 16:17, greg holly wrote:
> Hi all R-Help ,
> 
> After partitioning my data to testing and training (please see below), I
> need to estimate the Sensitivity and Specificity. I failed. It would be
> appropriate to get your help.
> 
> Best regards,
> Greg
> 
> 
> inTrain <- createDataPartition(y=data$case,
>                                 p=0.7,
>                                 list=FALSE)
> training <- data[ inTrain,]
> testing  <- data[-inTrain,]
> 
> attach(training)
> #model training and prediction
> data_training <- glm(case ~ age+BMI+Calcium+Albumin+meno_1, data =
> training, family = binomial(link="logit"))
> 
> predict <- predict(data_training, data_predict = testing, type = "response")
> 
> predict_testing <- ifelse(predict > 0.5,1,0)
> 
> # Sensitivity and Specificity
> 
>   sensitivity<-(predict_testing[2,2]/(predict_testing[2,2]+predict_testing[2,1]))*100
>   sensitivity
> 
>   specificity<-(predict_testing[1,1]/(predict_testing[1,1]+predict_testing[1,2]))*100
>   specificity
> 
> 	[[alternative HTML version deleted]]
> 
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-- 
Michael
http://www.dewey.myzen.co.uk/home.html



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