Statistics

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Boxcox transformation

Finding transformation for normal distribution

Visualize the random effects

http://www.quantumforest.com/2012/11/more-sense-of-random-effects/

Sensitivity/Specificity/Accuracy

Predict
1 0
True 1 TP FN Sens=TP/(TP+FN)
0 FP TN Spec=TN/(FP+TN)
N = TP + FP + FN + TN
  • Sensitivity = TP / (TP + FN)
  • Specificity = TN / (TN + FP)
  • Accuracy = (TP + TN) / N

ROC curve and Brier score

Elements of Statistical Learning

Bagging

Chapter 8 of the book.

  • Bootstrap mean is approximately a posterior average.
  • Bootstrap aggregation or bagging average: Average the prediction over a collection of bootstrap samples, thereby reducing its variance. The bagging estimate is defined by
[math]\displaystyle{ \hat{f}_{bag}(x) = \frac{1}{B}\sum_{b=1}^B \hat{f}^{*b}(x). }[/math]
  • ksjlfda

Hierarchical clustering

Take pomeroy data (7129 x 90) for an example:

lr = read.table("C:/ArrayTools/Sample datasets/Pomeroy/Pomeroy -Project/NORMALIZEDLOGINTENSITY.txt")
lr = as.matrix(lr)
hclust1 <- function(x) hclust(x, method="ward")
library(gplots)
heatmap.2(lr, col=bluered(75), hclustfun = hclust1, distfun = dist,
              density.info="density", scale = "none",               
              key=FALSE, symkey=FALSE, trace="none", 
              main = "Ward")

Hc ave.png Hc com.png Hc ward.png