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Color Palette and Enhancement Range

After opening the example data file, your CDAT window should look similar to the following:

CDAT window showing example sea surface temperature data with the default grayscale palette

You may notice a number of things here:

  • The data view is not very colorful or informative — we'll improve that in this exercise.
  • The variable selector above the data view is used to change the variable shown.
  • The control tabs on the left of the data view change how data is displayed in CDAT.
  • The color scale to the right shows the mapping of data values to colours.  In this case, the units for sea surface temperature (SST) are Kelvin, and the color palette is grayscale.
  • The track bar below the data view shows the location and data value under the mouse cursor.
  • A tool bar at the top has buttons for file operations and for navigating in the data view.

To improve the usefulness of the data view, try these steps:

  1. Click the  Color Palette control tab and select the HSL256 palette.
  2. Click the  Color Enhancement control tab and use the sliders to set the minimum to 294 and the maximum to 308, or use the text boxes and hit Enter after typing each number.

Your CDAT window should now look similar to the following:

CDAT window showing example sea surface temperature data with a colourful HSL256 palette

Bonus exercises:

  • Try choosing other color palettes to see what they look like.  
  • Try clicking the Help or ? button at the bottom of each control tab and read more about what the controls do.
  • Click the other buttons in the enhancement controls (Norm, Reverse, Reset) to see that they do. Try setting the function to Step and while adjusting the number of steps, notice how the color scale changes on the right.
  • Watch a YouTube video Links to an external site. on enhancements and palettes in CDAT.