altoslib: Use feet per second for imperial speed

This is more useful during descent than miles per hour...

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/altoslib/AltosConvert.java b/altoslib/AltosConvert.java
index 25bbf7a0c7709af62752f95685580a7b66f6a0f6..265b5f0f633e26a544203d83b188a52971166468 100644 (file)
--- a/altoslib/AltosConvert.java
+++ b/altoslib/AltosConvert.java
@@ -325,6 +325,14 @@ public class AltosConvert {
                return miles_to_meters(mps) / 3600;
        }
 
+       public static double mps_to_fps(double mps) {
+               return meters_to_miles(mps) * 5280;
+       }
+
+       public static double fps_to_mps(double mps) {
+               return miles_to_meters(mps) / 5280;
+       }
+
        public static double meters_to_mach(double meters) {
                return meters / 343;            /* something close to mach at usual rocket sites */
        }

diff --git a/altoslib/AltosSpeed.java b/altoslib/AltosSpeed.java
index fb1c5e3f48b8ccc6d74e6e636bf60688546736df..e09bbb7a0754b28ad8ed44fd9ab403fec2c632f1 100644 (file)
--- a/altoslib/AltosSpeed.java
+++ b/altoslib/AltosSpeed.java
@@ -21,29 +21,29 @@ public class AltosSpeed extends AltosUnits {
 
        public double value(double v, boolean imperial_units) {
                if (imperial_units)
-                       return AltosConvert.meters_to_mph(v);
+                       return AltosConvert.mps_to_fps(v);
                return v;
        }
 
        public double inverse(double v, boolean imperial_units) {
                if (imperial_units)
-                       return AltosConvert.mph_to_meters(v);
+                       return AltosConvert.fps_to_mps(v);
                return v;
        }
 
        public String show_units(boolean imperial_units) {
                if (imperial_units)
-                       return "mph";
+                       return "fps";
                return "m/s";
        }
 
        public String say_units(boolean imperial_units) {
                if (imperial_units)
-                       return "miles per hour";
+                       return "feet per second";
                return "meters per second";
        }
 
        public int show_fraction(int width, boolean imperial_units) {
                return width / 9;
        }
-}
\ No newline at end of file
+}