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The BTL Procedure

PROC BTL Statement

PROC BTL <options> ;

The PROC BTL statement invokes the procedure. You can specify the following options.


names the SAS data set to be used by PROC BTL. The default is the most recently created data set.


names the marker map data set to be used. It can include the variables Marker, Location, and Name and a user-designated linkage group variable. The user can specify the name of the numeric linkage group variable in the GROUP= option in the MARKER statement, and this data set must be sorted by this variable. The variable Marker must contain the names of the variables specified in the MARKER statement. If this variable is not in the MAP= data set, the order of the markers in the MARKER statement is used. The Name variable, if present in this data set, is displayed in the "Model Statistics" table when ALL=1 is specified in the MARKER statement. If the Location variable is in the data set, it is used for calculating the recombination parameters between pairs of markers, , when the PARMEST statement is given.

For a backcross, A is the default value for the homozygous genotype and B is the default value for the heterozygous genotype. For an F cross, A is the default value for the genotype homozygous in parent 1’s allele, B is the default value for the heterozygous genotype, and C is the default value for the genotype homozygous in parent 2’s allele. If values other than these are used, they need to be specified using the HOMOZYGOUS=, HETEROZYGOUS=, and HOMOZYGOUS2= options in the PARMEST statement.


suppresses the display of the "Marker Class Means" table.


suppresses the display of the "Parameter Estimates" table.


suppresses all output.


suppresses the display of the "Model Statistics" table.


specifies the sorting order for the levels of all CLASS variables. This ordering determines which parameters in the model correspond to each level in the data.

The default is ORDER=FORMATTED. When the default ORDER=FORMATTED is in effect for numeric variables for which you have supplied no explicit format, the levels are ordered by their internal values.

The following table shows how PROC BTL interprets values of the ORDER= option.

Value of ORDER=

Levels Sorted By


order of appearance in the input data set


external formatted value, except for numeric


variables with no explicit format, which are


sorted by their unformatted (internal) value


descending frequency count; levels with the


most observations come first in the order


unformatted value

For FORMATTED and INTERNAL, the sort order is machine dependent.

For more information about sorting order, see the chapter on the SORT procedure in the Base SAS Procedures Guide and the discussion of BY-group processing in SAS Language Reference: Concepts.

Note: This procedure is experimental.

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