git.gag.com Git - sw/motorsim/blob - src/com/billkuker/rocketry/motorsim/RocketScience.java

   1 package com.billkuker.rocketry.motorsim;\r
   2 \r
   3 import java.text.DecimalFormat;\r
   4 import java.util.HashSet;\r
   5 import java.util.Set;\r
   6 \r
   7 import javax.measure.quantity.Pressure;\r
   8 import javax.measure.quantity.Quantity;\r
   9 import javax.measure.unit.NonSI;\r
  10 import javax.measure.unit.ProductUnit;\r
  11 import javax.measure.unit.SI;\r
  12 import javax.measure.unit.Unit;\r
  13 import javax.measure.unit.UnitFormat;\r
  14 \r
  15 import org.jscience.physics.amount.Amount;\r
  16 \r
  17 public class RocketScience {\r
  18         public static Unit<Pressure> PSI = new ProductUnit<Pressure>(NonSI.POUND_FORCE.divide(NonSI.INCH.pow(2)));\r
  19         public static Unit<Impulse> NEWTON_SECOND = new ProductUnit<Impulse>(SI.NEWTON.times(SI.SECOND));\r
  20         static{\r
  21                 UnitFormat.getInstance().label(PSI, "psi");\r
  22                 UnitFormat.getInstance().label(NEWTON_SECOND, "Ns");\r
  23         }\r
  24 \r
  25         public interface MolarWeight extends Quantity {\r
  26                 public static final Unit<MolarWeight> UNIT = new ProductUnit<MolarWeight>(\r
  27                                 SI.KILOGRAM.divide(SI.MOLE));\r
  28         }\r
  29         \r
  30         public interface Impulse extends Quantity {\r
  31                 public static Unit<Impulse> UNIT = NEWTON_SECOND;\r
  32         }\r
  33 \r
  34         public static enum UnitPreference{\r
  35                 SI(new Unit[]{\r
  36                                 javax.measure.unit.SI.MILLIMETER,\r
  37                                 javax.measure.unit.SI.MILLIMETER.divide(javax.measure.unit.SI.SECOND),\r
  38                                 javax.measure.unit.SI.NEWTON,\r
  39                                 javax.measure.unit.SI.MEGA(javax.measure.unit.SI.PASCAL),\r
  40                                 NEWTON_SECOND\r
  41                 }),\r
  42                 NONSI(new Unit[]{\r
  43                                 javax.measure.unit.NonSI.INCH,\r
  44                                 javax.measure.unit.NonSI.POUND_FORCE,\r
  45                                 javax.measure.unit.NonSI.INCH.divide(javax.measure.unit.SI.SECOND),\r
  46                                 PSI,\r
  47                                 NEWTON_SECOND\r
  48                 });\r
  49                 \r
  50                 public static UnitPreference preference = SI;\r
  51                 \r
  52                 protected Set<Unit<?>> units = new HashSet<Unit<?>>();\r
  53                 \r
  54                 UnitPreference( Unit<?> u[] ){\r
  55                         for ( Unit<?> uu : u )\r
  56                                 units.add(uu);\r
  57                 }\r
  58                 \r
  59                 @SuppressWarnings("unchecked")\r
  60                 public <T extends Quantity> Unit<T> getPreferredUnit(Unit<T> u){\r
  61                         if ( units.contains(u) )\r
  62                                 return u;\r
  63                         for( Unit<?> ret : units ){\r
  64                                 if ( ret.isCompatible(u) ){\r
  65                                         return (Unit<T>) ret;\r
  66                                 }\r
  67                         }\r
  68                         return u;\r
  69                 }\r
  70         }\r
  71 \r
  72         public static <T extends Quantity> String approx(Amount<T> a) {\r
  73                 if (a == null)\r
  74                         return "NULL";\r
  75                 Unit<T> u = RocketScience.UnitPreference.preference.getPreferredUnit(a\r
  76                                 .getUnit());\r
  77                 double d = a.doubleValue(u);\r
  78 \r
  79                 DecimalFormat df;\r
  80 \r
  81                 if (Math.abs(d) < 10.0) {\r
  82                         df = new DecimalFormat("#.##");\r
  83                 } else if (Math.abs(d) < 100.0) {\r
  84                         df = new DecimalFormat("#.#");\r
  85                 } else {\r
  86                         df = new DecimalFormat("#");\r
  87                 }\r
  88 \r
  89                 return df.format(d) + " " + u.toString();\r
  90         }\r
  91 \r
  92 }\r