Interpretation of the Confusion Matrix

Actual Positive, Predicted Positive = TP Actual Positive, Predicted Negative = FN Actual Negative, Predicted Negative = TN Actual Negative, Predicted Positive = FP We know from the sample, Actual Positive = TP + FN Actual Negative = TN + FP Prevalence: If the sample can present the population, then prevalence is the ratio: Actual …

Useful functions in “reshape2” package in R —- stack(), melt()

  In many situations, data is presented in a format that is not ready to dive straight to exploratory data analysis or to use a desired statistical method. The reshape2 package for R provides useful functionality to avoid having to hack data around in a spreadsheet prior to import into R. stack() function For example, we have the data frame read …

The logic behind the hypothesis Testing and p value

The logic behind the hypothesis testing There are two ways to prove your research hypothesis. For example, you want to prove the average grade of English class is higher than 60. You can prove it directly if you have all the information about your interested population. For example, if you are interested in the average …