Wavelet Toolkit Dataset Viewer

Your dataset can consist of several different variables, each with a different data format. The Dataset Viewer, located in the middle of the Wavelet Toolkit applet, allows you to organize and manipulate your dataset.

The variables are assigned a number and a name derived from the Variable name. You can sort the variables using the Move Variable Left and Move Variable Right buttons.

Variable Information

Each variable contains a one-dimensional vector or two-dimensional array of data values. The data values can be of any numeric type, such as BYTE, INTEGER, FLOAT, etc.

The variable also has several descriptor fields which you can modify, described below and summarized in the table below. To modify a field, double-click with the left-mouse button on the field. After editing the field, press the <Return> key to keep your changes or, click outside of the table to discard your changes.

Type

This string shows the numeric type and the array size of the data. It is not modifiable by the user.

Title

This string contains the overall name of the variable. The Title field is used to label the Wavelet Power Spectrum and Multiresolution widgets. The default is the null ('') string.

Variable

This string provides a short name for the variable. The Variable is used to label plots, and for the labels in the Dataset Viewer. For a one-dimensional vector (e.g. a time series), the Variable is equivalent to Ytitle. The default is either the name of the import file, or 'Data' if imported from the IDL> command prompt.

Units

This string gives the units of the variable, and is used to label various plots. For a one-dimensional vector (e.g. a time series), the Units is equivalent to the Yunits. The default is the null ('') string.

Table 2-1: Data fields in the Dataset Viewer .
Field	Type	Example (1D vector)	Example (2D array)
Title	STRING	Wave audio recording	IEEE Test Image
Variable	STRING	Channel1	IEEEtest
Units	STRING	Amplitude	intensity
Xname	STRING	Time	X
Xunits	STRING	seconds	pixels
Xstart	STRING	0	0
Dx	STRING	1d0/22050	1
Yname	STRING		Y
Yunits	STRING		pixels
Ystart	STRING		0
Dy	STRING		1
Xoffset	LONG	0	0
Xcount	LONG	16384	256
Xstride	LONG	1	2
Yoffset	LONG		0
Ycount	LONG		256
Ystride	LONG		2
Source	STRING	wavelet/data/hello.wav	wavelet/data/IEEEtest.tif
Notes	STRING	Voice saying `hello'	IEEE test image

Xname

This string is the name of the independent variable for the first data dimension ("X"), and is used to label the x-axis. The default is the null ('') string.

Xunits

This string gives the units of X. The default is the null ('') string.

Xstart

This string gives the value of the first X coordinate. The default is '0'. Xstart can contain complicated mathematical expressions, although the result must be a scalar number.

Dx

This string gives the sampling interval between the X coordinates. The default is '1'. Dx can contain complicated mathematical expressions, although the result must be a scalar number.

Yname

This string is the name of the independent variable for the second data dimension ("Y"), and is used to label the y-axis (for a one-dimensional variable this is actually equivalent to the name of the dependent Variable). The default is the null ('') string.

Yunits

This string gives the units of Y. The default is the null ('') string.

Ystart

This string gives the value of the first Y coordinate. The default is '0'. Ystart can contain complicated mathematical expressions, although the result must be a scalar number.

Dy

This string gives the sampling interval between the Y coordinates. The default is '1'. Dy can contain complicated mathematical expressions, although the result must be a scalar number.

Xoffset

The offset along the first data dimension at which to start. The default is 0L.

Xcount

The number of data points to use along the first data dimension. The default is the size of the first dimension.

Xstride

The sampling interval along the first data dimension. The default is 1L.

Yoffset

This long integer gives the offset along the second data dimension at which to start. The default is 0L.

Ycount

This long integer gives the number of data points to use along the second data dimension. The default is the size of the second dimension.

Ystride

This long integer gives the sampling interval along the second data dimension. The default is 1L.

Source

This string describes the original source or location of the data. The default is either the full filename (if the data was from a file) or 'Imported' (if the data was from the IDL> command prompt).

Notes

You can enter miscellaneous information into the Notes string. The default is the null ('') string.

Mathematical Expressions

For Xstart, Dx, Ystart, and Dy, it is highly recommended that whenever possible you enter mathematical expressions, rather than converting to numbers. For example, in the above table, the sampling rate for hello.wav is 22050 Hz. One could have entered Dx as 0.00004535 rather than `1d0/22050'. Nevertheless, the latter is not only more accurate (limited only by your computer's precision) but is also much more informative. (Note that the `1d0' forces the computation to be done in double precision.)

You may also enter IDL functions in these strings. For example, if your X coordinate was in Julian days, starting from say 29 February 2000, you could set Xstart = 'JULDAY(2,29,2000)'.

Selecting Variables

To select a particular variable for visualization or some other action, click the mouse on any field for that variable, or click the mouse on the Table row label to highlight the entire row.

To select multiple variables for deletion, click the mouse on any field and drag down to select the list of variables, or click once on the row label, scroll down and hold the <Shift> key while clicking on the last row label.