You are here: Vanderbilt Biostatistics Wiki>Main Web>Education>IntroBiostatCourse2007>IntroBiostatCourse2007StataLab (01 Mar 2007, LeenaChoi)EditAttach

- Some of materials were copied/modified from course materials of Biostatistics, M.P.H. program at Vanderbilt University, and the course textbook, "Statistical Modeling for Biomedical Researchers", 2nd Ed.,
*in press*, by William Dupont. [WD] refers to William Dupont's book

- enter a dataset displayed in Table 4.1
- assign the data description
- make a note which documents the source of the data and the date of creation
- label each variable
- use
`codebook`

,`describe`

, and`summarize`

- save the commends that used so far in the review window as do file

- download Haemoglobin and use
`infile`

command to import the data:`infile id hemo using "C:\Teaching\IGP\data\haemoglobin.txt", clear`

- make a box plot : go to Stata pulldown menus --> Graphics --> Box plots, choose
*hemo*in the box called "Variables" - observe what appears in the review window

- see
`help axis_options`

- make Fig. 3.8: put a main title and a subtitle (name them whatever you want) using
`title`

and`subtitle`

- make Fig. 3.9: put the x title, add the x tick marks to the x-axis from 7 to 11 in units of 1, and add the x minor tick marks to the x-axis at 7.5, 8.5, 9.5, 10.5
- make Fig. 3.10-3.11: put x and y axis labels and tick marks, and put the main, x and y axis titles
- make Fig. 3.12: put a main title and the y axis title

- Use Haemoglobin in Table 3.2:
- calculate the mean and standard deviation for haemoglobin using the code provided in Stata notes for classes [EMS] Chapter 4.
- compare the results with the output using
`summarize`

- Stata Lab: calculate the following values using the code provided in Stata notes for classes [EMS] Chapter 5
- find the area in upper tail of the standard normal distribution for
**_z = 1.975_** - find the area in lower tail of the standard normal distribution for
**_z = -1.95_** - find the area of the standard normal distribution between two values,
**_z = -1_**and**_z = 1_** - find the area of the standard normal distribution between two values,
**_z = -2.58_**and**_z = 2.58_**

- find the area in upper tail of the standard normal distribution for

- R Lab: The purpose of this lab is to examine how the standard deviation of a population and the sample size of a trial affect the standard errors using the code provided in R notes [EMS] Chapter 4.
- download R 2.4 official site and open R
- open a text editor
- copy the code to the text editor
- change the values of the s.d of the population
**_sigma_**and the number of observation in each sample,**n**e.g.`sigma <- 20`

,`n <- 5`

in R - copy the modified code and paste to R (do not copy the whole commands; copy several lines at each time)
- observe how the standard errors change as function of
**_sigma_**and**n**

- Calculate confidence interval for a mean for [EMS] Example 6.3 on page 55 using the code provided in Stata notes for classes [EMS] Chapter 6

- Compare two means using the code provided in Stata notes for classes [EMS] Chapter 7

- Generate ANOVA Table 9.1 (c) using the code provided in Stata notes for classes [EMS] Chapter 9
- then calculate F value

- Reproduce the tables on Chapter 10 using the code provided in Stata notes for classes [EMS] Chapter 10
- Draw a scatter plot with the estimated linear regression line and 95% confidence band

- Learn how to run simple linear regression

- Reproduce Table 11.3 and 11.4 on Chapter 11 using the code provided in Stata notes for classes [EMS] Chapter 11
- Learn how to generate dummy variables

- Draw inverse normal plots and plots of residuals against fitted values on Chapter 12 using the code provided in Stata notes for classes [EMS] Chapter 12

Edit | Attach | Print version | History: r22 < r21 < r20 < r19 | Backlinks | View wiki text | Edit wiki text | More topic actions

Topic revision: r22 - 01 Mar 2007, LeenaChoi

Copyright © 2013-2022 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.

Ideas, requests, problems regarding Vanderbilt Biostatistics Wiki? Send feedback

Ideas, requests, problems regarding Vanderbilt Biostatistics Wiki? Send feedback