Working with Unknown Data
If you supply data in a format not recognized by the current iTool, the Create Visualization dialog allows you to specify how the data is to be used.
Figure 2-5: The iTools Create Visualization Dialog
Figure 2-5: The iTools Create Visualization Dialog
|
You will see this dialog if the data you supply when launching an iTool from the IDL command line does not match a known data organization for the selected tool, or if you open an ASCII text file containing data that appears to be irregularly gridded.
The Create Visualization dialog contains the following choices:
- Launch the gridding wizard
This option lets you transform irregularly-gridded data into regularly-gridded data using IDL's gridding routines. The resulting data is displayed by the iTool. See Using the Gridding Wizard for details.
- Select a visualization and specify parameters
This option lets you manually specify how the data should be assigned to a selected visualization's parameters.
- Do not create a visualization
Using the Gridding Wizard
The iTools Gridding Wizard allows you to convert irregularly-gridded data into regularly-gridded data using a variety of methods. The gridding wizard processes your irregularly-gridded data in three steps.
Figure 2-6: The IDL Gridding Wizard Step 1 of 3
Figure 2-6: The IDL Gridding Wizard Step 1 of 3
|
The IDL Gridding Wizard Step 1 of 3 dialog contains the following items:
- Number of points entered
- X Coordinates — The X coordinate range
- Y Coordinates — The Y coordinate range
- Data values — The data minimum and maximum values
- Spherical data checkbox — Check this box if the data is spherical
- Coordinate diagram — Shows coordinates of grid data
- Show points checkbox — Select to show all points (default = checked)
- Help — Obtain help on this dialog
- Back — Return to previous step
- Next — Proceed to Step 2 of 3
- Cancel — Dismiss the Gridding Wizard
Figure 2-7: The IDL Gridding Wizard Step 2 of 3
Figure 2-7: The IDL Gridding Wizard Step 2 of 3
|
The IDL Gridding Wizard Step 2 of 3 dialog contains the following items:
- X Coordinates — modify dimension, start or end
- Y Coordinates — modify dimension, start or end
- Coordinate diagram — shows coordinates of grid data
- Show points checkbox — select to show all points (default = checked)
- Help — obtain help on this dialog
- Back — return to previous step
- Next — proceed to Step 3 of 3
- Cancel — dismiss the Gridding Wizard
Figure 2-8: The IDL Gridding Wizard Step 3 of 3
Figure 2-8: The IDL Gridding Wizard Step 3 of 3
|
The IDL Gridding Wizard Step 3 of 3 dialog contains the following items:
- Choose gridding method — choose from pull-down list. See GRIDDATA for a discussion of the gridding methods.
- Preview — click to preview selected method and data
- Auto preview — checkbox to turn auto preview on (default = off)
- Statistics tab — shows data statistics
- Options tab — set options for missing values, smoothing, weighting, and anisotropy between axes
- Search tab — set options for using search ellipse
- Coordinate diagram — shows coordinates of grid data
- Show points checkbox — select to show all points (default = checked)
- Help — obtain help on this dialog
- Back — return to previous step
- Finish — dismiss the Gridding Wizard with data gridded
- Cancel — dismiss the Gridding Wizard
IDL Online Help (March 01, 2006)