run regression in R

Gelman: I really hate to think that there are people out there running regressions in R and not using display() and coefplot() to look at the output.

Metric MDS starting from eigen()

this is an exercise to figure the details of MDS, or more specifically, what the coordinates are that are used in plotting. More explanations can be found here.

geometric interpretation of vector operatiom

here

average heterzygosity

from Ascertainment bias in studies of human genome-wide polymorphism
A simple comparison of the HapMap and Perlegen genotype data was done by considering the 5682 windows of 500 kb across the entire genome and, for each window, tallying the SFS and calculating summary statistics such as average heterozygosity for each population and FST for each population pair and for the trio of samples.

The average uncorrected heterozygosity within the three population groups for the HapMap data were 0.281, 0.247, and 0.268 for the Yoruban, Chinese, and European samples. The corresponding figures for the uncorrected Perlegen data are 0.251, 0.211, and 0.229 for the African American, Chinese, and European samples.

histograms are like this.

2D plotting in SAS

This example shows a regression plot with prediction and confidence limits.

proc sgplot data=sashelp.class;
  reg x=height y=weight / CLM CLI;
run;