The macros below are ”home made” and not guaranteed to work well under all circumstances. If you have problems, it may be useful to start with a MINITAB worksheet which is empty in all other columns than the ones that are given as input. If you improve some of the macros, then you may well send them to the lecturer (who may put them here).
Note that if you put the macro on an address which contains blanks, then the address must be written in “quotes”, i.e. ‘ ‘ , for example
MTB> %’C:\your minitab directory\TMA4275nelson.txt’ c1-c7
You are advised to always use the quotes when using the macros (see examples
below).
More detailed description of how to use the macros is given below. You may also download the
macros from here.
Nelson-plot – User’s manual
· Download the file and put it (for example) in the directory
C:\yourdirectory\
· Let (for example) column C1 contain the observed times, in increasing order, and let C2 contain the censoring status (with 1 for lifetime and 0 for censoring time).
· In MINITAB 19 you use the Command Line in the window appearing to the right on the screen. In older versions you first click in the “Session” window. Then you activate "Enable Commands" from the menu under "Editor" at the top of the MINITAB page.
· The statement
MTB> %’C:\yourdirectory\TMA4275nelson.txt’ c1-c7
will then put the results in C3-C7.
TTT-plot (noncensored data)-- User’s manual
· Download the file and put it (for example) in the directory
C:\yourdirectory\
· Let (for example) column C1 contain the observed times, in increasing order. Remember: no censoring times.
· See Nelson-plot for how to use the macro.
· The statement
MTB> %’C:\ yourdirectory\TMA4275tttplot.txt’ c1-c5
will then put the results in C2-C5, in the same order as in Table 11.5/9.1 in the book.
TTT-plot og
Barlow-Proschan’s test (censored
data)— User’s manual
· Download the file and put it (for example) in the directory
C:\yourdirectory\
· Let (for example) column C1 contain the observed times, in increasing order, and let C2 contain the censoring status (with 1 for lifetime and 0 for censoring time).
· See Nelson-plot for how to use the macro.
· The statement
MTB> %’C:\ yourdirectory\TMA4275barlowpro.txt’ c1-c8
will then put the results in C3-C8. The column C6 contains ”total time on test” in the times where there was a failure (i.e. where column C2 is 1). The TTT-plot is a plot of the points (C7,C8). The test statistic W in Barlow-Proschan’s test is found by adding the last column (”TTT”) and not include the 1.0.