Creates a table from one or more vectors (one-dimensional arrays).

vari—A vector (one-dimensional array) variable. If additional vectors are specified, they must contain the same number of elements as vari. The input variable(s) can be of any data type.

alias—(optional) Specifies a new name for the table column. By default, the input variable’s name is used.

result—A table containing n columns, where n is equal to the number of input variables.

In_Structure—A scalar string expression that specifies the name of a PV‑WAVE structure to use to create the result table. This structure can either be defined by the user, or obtained from the Out_Structure keyword from a previous BUILD_TABLE call. If user-defined, the tag definitions of this structure must meet the requirements for PV‑WAVE table variables. If no value is specified by In_Structure, PV‑WAVE creates a new named structure, based on the types of the column variables specified in the parameter string. The purpose of this keyword is to allow you to append new rows to an existing table variable.

Out_Structure—A string variable which receives the name of the PV‑WAVE structure that was used to create the result table. The purpose of this keyword is to allow you to append rows to the result table with subsequent calls to BUILD_TABLE. In this scenario, Out_Structure is used to save the name of the structure created during the first BUILD_TABLE call. This same structure name is used (with the In_Structure keyword) to append rows to the result table.

Once created, you can subset the table using the QUERY_TABLE function. Each vector must have the same number of elements. If not, an error message is displayed and the table is not created.

A table is built from vector (one-dimensional array) variables only. You cannot include expressions in the BUILD_TABLE function. For example, The following BUILD_TABLE call is not allowed:

result = BUILD_TABLE('EXT(0:5), COST(0:5)')

However, you can achieve the desired results by performing the array subsetting operations first, then using the resulting variables in BUILD_TABLE. For example:

EXT = EXT(0:5)

COST = COST(0:5)

result = BUILD_TABLE('EXT, COST')

In addition, you cannot include scalars or multidimensional-array variables in BUILD_TABLE.

The following command creates a table consisting of eight columns of data. The data used to create the table has been included in a file. Enter the following command at the WAVE> prompt to restore the data:

The columns are created from data read into PV-WAVE and placed into vector variables.

phone_data = BUILD_TABLE('DATE, TIME, ' + $

   'DUR, INIT, EXT, COST, AREA, NUMBER')

Table 3-2: Phone Data Table shows a portion of the resulting table.

Use the INFO command to view the new table structure, for example:

INFO, /Structure, phone_data

** Structure TABLE_0, 8 tags, 40 length:

The Structure keyword is used in this example because tables are represented in PV-WAVE as an array of structures.

The QUERY_TABLE function can be used to retrieve information from this table. For example:

res = QUERY_TABLE(phone_data, ' * Where COST > 1.0')

This query produces a new table containing only the rows where the cost is greater than one dollar.

This example demonstrates the use of the optional alias parameter. This parameter lets you specify new names for the columns of the table. By default, the names of the input variables are used as column names.

phone_data1 = BUILD_TABLE('DATE Call_Date,' + $

   TIME Call_Time, DUR Call_Length,' + $

   'INIT, EXT, COST Charge, AREA Area_Code,'+ $

   'NUMBER Phone_Number')

The structure of this table reflects the new column names:

INFO, /structure, phone_data

** Structure TABLE_0, 8 tags, 40 length:

GROUP_BY,  ORDER_BY,  QUERY_TABLE,  UNIQUE

For more information on BUILD_TABLE, see the PV‑WAVE User’s Guide.

For information on reading data into variables, see the PV‑WAVE Programmer’s Guide.