Macro basics

In This Topic

What is a macro?
How do I create an Exec (.MTB file) to automate a series of procedures I often run in Minitab?
How do I run an Exec (.MTB file) to automate a series of procedures I often run in Minitab?
Can I use ODBC (Open Database Connectivity) in a macro?

What is a macro?

A macro is a text file that contains a series of Minitab session commands. You can use macros to automate a repetitive task (for example, generating a monthly report) or to extend Minitab's functionality (for example, computing a special test statistic).

You can run macros in both the desktop and web apps versions of Minitab Statistical Software.

The following types of macros are available in Minitab:

Global macros (.MAC files)

Allow you to analyze and manipulate data in the active worksheet. However, the identity of any columns, constants, and matrices that are to be accessed must be specified within the macro; therefore, the worksheet must be configured the same way each time the macro is run.

GMACRO 
NOMISS    
LET K90 = COUNT('X') 
DO K91 = 1:K90 
  IF  'X'[K91] = '*' 
  DELETE  K91:K90 'X' 
    BREAK 
  ENDIF 
ENDDO 
ENDMACRO

Example

This macro (NOMISS) looks for the first missing observation in a column named X, then deletes the remainder of the column.

Local macros (.MAC files)

More powerful and flexible than global macros because they can accept arguments and have their own subcommands. Users specify the data to be processed when they run the macro, making the data setup more flexible. However, local macros are also more complicated to write than global macros.

MACRO 
MNSTD x y z 
MCOLUMN x y z v 
MCONSTANT N i k1 k2 
MRESET 
BRIEF 0 
LET N=count(x) 
LET y(1)='*' 
LET z(1)='*' 
DO i=2:N 
COPY x v; 
USE 1:i. 
LET y(i)= MEAN(v) 
LET z(i)= STDEV(v) 
ENDDO 
ENDMACRO

Example

This macro (MNSTD) calculates the mean and standard deviation for the first two rows of a column, then the first three rows, and so on.

Exec files (.MTB files)

A simpler form of Minitab macro; execs cannot have control statements or accept arguments and subcommands when run. Exec files can be useful if you want to rerun a series of commands you just ran.

HISTOGRAM C1 C2;
    YFrequency;
    Bar;
    Panel.

Example

For example, create an exec to recreate a graph you made earlier in your Minitab session. This exec draws a histogram of frequency for two columns and panels them.

How do I create an Exec (.MTB file) to automate a series of procedures I often run in Minitab?

The easiest way to create an Exec file is to save command language from the History pane.

Note

The following steps will save all the commands in the History pane. If you have just a few lines that you want to save from the History pane, highlight them, and copy and paste into a text editor, such as Notepad, then save the file using a .mtb file extension.

Run the commands that you want the Exec file to contain.
Press CTRL+K to open the History pane.
Right-click in the History pane, then choose Save History As.
Browse to the folder that you want to save your files in. In File name, enter Histogram.
From Save as type, select Exec (*.mtb). Click Save.

How do I run an Exec (.MTB file) to automate a series of procedures I often run in Minitab?

Choose File > Run an Exec.
Specify the Number of times to execute.
Click Select File.
Click the desired file (for example, TEST.MTB). Click Open.
Tip
To run an Exec, you could also drag and drop the Exec file on a Minitab shortcut.

Can I use ODBC (Open Database Connectivity) in a macro?

Yes. The COLUMNS subcommand is required in local macros. COLUMNS specifies which columns of the Minitab worksheet should hold the data. In global macros or exec files, executing the ODBC command without the COLUMNS subcommand places new data at the end of the global worksheet.