__Title__

**[P] _ms_at_parse** -- Parse **at()** specifications for postestimation commands

__Syntax__

**_ms_at_parse** [*at_list*] [**,** __asobs__**erved**]

*at_list*:
*at_spec* *at_list*
*at_spec*
''

*at_spec*:
**(** *at_stat* **)**
*at_var*

*at_stat*:
**mean** or **omean**
**median** or **omedian**
**min** or **omin**
**max** or **omax**
**p1** or **op1**
...
**p99** or **op99**
**zero**
__asbal__**anced**
__asobs__**erved**
**base**

*at_var*:
*indepvar*
*indepvar* **=** *value*
*indepvar* **=** **(** *numlist* **)**
*indepvar* **=** __gen__**erate(***exp***)**
___c__**ontinuous**
___f__**actor**
**_all**
*****

where *value* is a numeric (nonmissing) value, *exp* is a numeric expression
allowed by the **generate** command, and *indepvar* is any valid single
variable specification that identifies an independent variable
participating in the column stripe for **e(b)**, for example, standard
variables with or without time-series operators, and factor-level
variables (but not interactions of variables).

**_continuous** is a shortcut notation that means all the continuous
*indepvar*s.

**_factor** is a shortcut notation that means all the factor-variable
*indepvar*s.

**_all** and ***** are synonyms for **_continuous** **_factor**.

Although an *indepvar* can be specified multiple times, only the rightmost
*at_stat* has any affect, and only if the *indepvar* is not associated with
*value* or *numlist*.

__Description__

**_ms_at_parse** parses the contents of the standard **at()** option for some of
Stata's postestimation commands.

__Option__

**asobserved** indicates that any unspecified independent variable is to be
left as observed. The default is to associate **(mean)** with each of
the unspecified independent variables.

__Stored results__

**_ms_at_parse** stores the following in **r()**:

Macros
**r(statlist)** list of expressions or keywords associated with each
of the *p* independent variables participating in
the column names of **e(b)**; a keyword is either
**asobserved** or one of the *at_stat*s
**r(atvars)** list of variable names explicitly specified in
*at_list*; this list preserved the order in which
the variables were specified

Matrices
**r(at)** a *k* x *p* matrix with *k* patterns of values associated
with the full set of *p* independent variables
participating in the column names of **e(b)**