Importing Data into the Wavelet Toolkit

You can import data in multiple file formats into the IDL Wavelet Toolkit.

ASCII Files

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Select this menu item or button to import data from an ASCII text file. After choosing the file using the Select Import File dialog, you can specify the particular format for the ASCII_TEMPLATE dialog. See "ASCII_TEMPLATE" (IDL Reference Guide) for more information.

The ASCII_TEMPLATE routine handles ASCII files consisting of an optional header of a fixed number of lines, followed by columnar data. The procedure consists of three steps:

  1. "Define Data Type/Range"— Specify whether the data is in fixed width columns or separated by commas or spaces. The first 50 lines are displayed. Choose the first line of data and click on the Next > button;
  2. "Define Fields"— Choose the number of fields per line and then click Next >;
  3. "Field Specification"— You can change the names and data types for the various fields. The Field names can also be changed once the data is imported into the Toolkit. Click on the Finish button to import the data into the Wavelet Toolkit.

Once the data is successfully imported, you can change the default names for the variable Title, Variable, etc.

Independent Variable

For ASCII files with multiple columns, if the first column is determined to be monotonically increasing in value, or is assigned the field name "TIME" within the ASCII_TEMPLATE, then it is assumed to be the "independent variable." In this case the remaining columns are then imported as the "dependent variables."

Note
You may change the name "TIME" after the data has been imported into the Wavelet Toolkit.

Two-Dimensional Arrays

By default, each column within the file will be imported into the IDL Wavelet Toolkit as a separate variable. To import a two-dimensional array of data, you should use the Group All button within the ASCII_TEMPLATE dialog to connect all of the columns into one field.

Binary Files

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Select this menu item or button to import data from a binary data file. After choosing the file using the Select Import File dialog, you can specify the particular format for the file using the BINARY_TEMPLATE dialog. See "BINARY_TEMPLATE" (IDL Reference Guide) for more information.

The BINARY_TEMPLATE routine handles raw binary files consisting of headers and multiple data fields. The dialog consists of a Binary Template window where you can define various fields within the file. Each field will be imported into the Wavelet Toolkit as a separate variable.

Image Files

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Select this menu item or button to import an image file. The function DIALOG_READ_IMAGE is used to select the image file. For files with multiple images you can choose the particular image you wish to import. See "DIALOG_READ_IMAGE" (IDL Reference Guide) for more information.

For TrueColor (24-bit) images, you will then be asked how you wish to convert the three channels into a single two-dimensional image. You have the option to scale the data into an intensity from 0–255, quantize the 24-bit colors down to 256 colors, or split the three channels into separate red, green, and blue images.

WAV Audio Files

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Select this menu item or button to import a .WAV (RIFF) audio file as a one-dimensional vector. The file must be in uncompressed PCM format. Multiple channels are imported as separate variables, one for each channel.

IDL Command Line

You can also import data directly from the IDL> command prompt using the WV_IMPORT_DATA command: 

WV_IMPORT_DATA, variable

where variable is either a data vector or array, or a structure of data tags (see WV_IMPORT_DATA for tag information).

If there is more than one Wavelet Toolkit applet currently running, then variables are entered into the one that was most-recently active.