Zhongheng Zhang

4 Questions 21 Answers 0 Followers

Questions related from Zhongheng Zhang

How can I make sample size calculation for cohort study with exposure factor clustered in hospitals?

I am planning a study which involves 7 hospitals. three hospitals used A for the treatment of a disease; and the remaining four hospitals used B. The aim of the study is to investigate the...

12 December 2016 1,251 4 View

How to use par(mfrow=c(2,2)) with for loop, with ggplot function within the loop?

Dear all, I have the following question: first I present the R...

08 August 2016 3,770 0 View

How to add regression line to a heat map?

Hi, every one. I am currently working on a project using heat map. however, many heat map packages provided by R does not allow addition of a regression line to each cells. in my example, each...

08 August 2016 8,602 5 View

Question on structrural equation model diagram produced by pathDiagram?

When drawing a diagram using R command pathDiagram. I found that the values labels displayed above edge is not the parameter estimates. the help file of pathDiagram states...

07 July 2016 2,975 2 View