Unidata IDV Workshop for version 3.0u1 > Accessing and Displaying Data > Working with Gridded Data
3.2.10 Working with Large Grids
Displaying high resolution grids in the IDV can be memory
intensive. If you are reading from a remote server, you also
have to deal with the latency of reading the grids across the
internet. There are several strategies you can use to reduce
the amount of memory used by the IDV.
- First, let's load in a high resolution grid.
- If you have not already done so, use the
menu to remove the displays
created in the previous exercise.
- In the
Catalog data chooser, select the
dataset.
- Now, let's subset the grid.
- Open the
Data Source Properties editor for Latest NCEP NAM CONUS 12km.
- You can subset the grid by time and/or by coverage.
- Click on the
Times tab. Uncheck the
Use All box. Right click on the panel
and select the menu option.
- Click on the
Spatial Subset tab. You can spatially
subset the grid by stride (e.g. every nth point) and/or by
region. Set the X Stride to
Every third point. Notice that the
Y Stride is linked to the X Stride.
- Optionally, keep the stride at
All points and
select a sub-region on the map.
- In the
Field Selector, select the
3D grid->Temperature @ pressure field and
the Contour Plan View display.
- Since we are displaying a single level, you can further reduce
the grid by selecting a level instead of the entire grid.
In the
Level tab of the Data Subset panel,
select the 50000 Pa (500 millibar) level.
- Click the
Create Display button.
- For more information on performance tuning, see the
Performance Tuning
section of the IDV User's Guide.
Unidata IDV Workshop for version 3.0u1 > Accessing and Displaying Data > Working with Gridded Data
