Synopsis
reads an ASCII file containing any number of separated columns
Input Ports
|
parent |
UIconnection |
Parameters
|
Filename |
UIfileSB |
name of the file to read |
|
skip lines |
UIfield |
number of lines to skip |
|
has header line |
UItoggle |
if set, use header to get column names |
|
column separator |
UIradioBox |
selects column separator |
|
user separator |
UIfield |
custom column separator |
|
columns setup from file |
UItoggle |
if set, column names and types are determined automatically by reading first lines of file |
|
# columns in file |
UIfield |
number of columns in file |
|
Columns Setup |
UIoptionMenu |
selects a column whose parameters are to be set |
|
read column |
UItoggle |
if set, read this column |
|
column name |
UIfield |
name of the column |
|
data type |
UIradioBox |
selects the type of a column |
|
null value |
UIfield |
value for missing column entries |
|
Read File |
UIbutton |
causes file to be read |
Output Ports
|
table |
Data_Array |
Description
The Read_Column_File module reads any ASCII file that contains columns of data separated by a special character or sequence of characters. The columns in the file can be of any type: character strings, integers, or real numbers. Optionally, the file can have a header line that contains the column's names. The module stops reading when it reaches the end of the file.
Here are some simple examples of column-formatted ASCII files. The following file has three columns separated by spaces:
1 bob 180.3
2 jim 230.65
3 bill 201.6
The next file contains the same three columns of data, but the columns are separated by (nonprinting) tab characters and the file has a header:
# name weight
1 bob 180.3
2 jim 230.65
3 bill 201.6
Column-formatted ASCII files are produced by many software packages; spreadsheets are common examples.
Read_Column_File provides a number of column parameters that you can use to specify whether and how individual columns in the file are processed. You use the Column Setup menu to specify a column whose parameters you want to set, and then use the following parameters to set processing specifics:
read column
For details, see their descriptions in the Parameters section of this reference page.
Read_Column_File outputs an array of objects of type Data_Array. You can map the output to the Uniform_Field or Scattered_Field types using the Database Kit modules Table_to_Uniform_Field or Table_to_Scattered_Field. Once mapped to Uniform_Field or Scattered_Field, the data is suitable for visualizing in AVS/Express.
Note: This module may be useful to Database Kit application developers because it allows the use of ASCII files, rather than a database, to provide sample "query output" for testing Database Kit applications. Using an ASCII file instead of establishing a test database with tables, views, and data may therefore simplify testing.
Input Ports
parent
The UI parent, of type UIconnection.
Parameters
Filename
A file dialog box in which you select the file to read.
skip lines
An integer that specifies the number of lines in the file to skip. The default is 0.
has header line
A toggle that causes the module to treat the first line (after skipping the number of lines specified by the skip lines parameter) as a header that contains column names. The default is OFF.
column separator
A choice of characters to use as column separators. The allowed values are "space", "tab", ",", ";", ":", and "user". If you select "user", the value specified for the user separator parameter is treated as the column separator.
user separator
A string that specifies a character or sequence of characters to be used as column separator.
This parameter is relevant only if you have also selected "user" in the column separator parameter.
columns setup from file
A toggle that causes the module to look at the first lines of the file to generate column names and types. If the has header line parameter is set, the header is used to generate column names, otherwise the names are "column 0", "column 1", and so forth. The type for each column is determined by examining the line following the header, if one exists.
# columns in file
An integer typein that specifies the number of columns in the file. If the columns setup from file parameter is set, this number is generated automatically, otherwise you must enter it.
Columns Setup
A menu that allows you to specify a column whose parameters you want to set.
read column
A toggle that specifies whether to read the column specified by Columns Setup or skip it.
column name
A string typein that specifies the name of the column specified by Columns Setup. If the columns setup from file parameter is set, the column names are generated automatically from the header if one exists, otherwise they are assigned default names. You can overwrite this string with a name of your choice.
data type
Radio box items that specify the type of the output data for the column specified by Columns Setup. The allowed values are byte, short, int, float, double, and string.
null value
A value that is to be used to represent a null value for the column specified by Columns Setup if Read_Column_File encounters a missing entry. This parameter is used only for numeric types. For strings, the "" string is substituted for a missing entry.
Read File
A button to activate the module.
Output Ports
table
An array of objects of type Data_Array. It can be converted to the Uniform_Field or Scattered_Field types using the table_to_uniform_field and table_to_scattered_field modules.
File
/modules.v
See also