Programmatically Interact with Gauge Band Colors

You can programmatically change Airspeed Indicator, EGT Indicator, and RPM Indicator gauge band colors using the ScaleColors property. When used with get_param, this property returns an n-by-1 structure containing these elements, where n is the number of colored bands on the gauge:

• Min — Minimum value range for a color band

• Max — Maximum value range for a color band

• Color — RGB color triplet for a band (range from 0 to 1)

This example describes how to change a color band of the EGT Indicator gauge. By default, the EGT Indicator gauge looks like this.

This gauge has three bands, clockwise 1, 2, and 3.

1. Create a blank model and add an EGT Indicator block.

2. Select the EGT Indicator block.

3. To change the color bands for the EGT Indicator gauge, get the handle of the scale color objects.

   sc=get_param(gcb,'ScaleColors')

   sc = 
   
     3×1 struct array with fields:
   
       Min
       Max
       Color

4. To see the values of the Min, Max, and Color values, use the sc handle. For example, to see the values of the first band, sc(1), type:

   sc(1)

   sc(1)
   
   ans = 
   
     struct with fields:
   
         Min: 0
         Max: 700
       Color: [0.2980 0.7333 0.0902]

5. To change the color and size of this band, define a structure with different Min, Max, and Color values and set ScaleColors to that new structure. For example, to change the band range to 1 to 89 and the color to red:

   sc(1) = struct('Min',1,'Max',89,'Color',[1 0 0]);
   set_param(gcb,'ScaleColors',sc)

6. Observe the change in the EGT Indicator gauge.

   

7. You can add and change as many color bands as you need. For example, to add a fourth band and set up the gauge with that band:

   sc(4) = struct('Min',200,'Max',300,'Color',[0 1 .6]);
   set_param(gcb,'ScaleColors',sc)