Package healpix.essentials

Class HealpixUtils

  • public class HealpixUtils
extends java.lang.Object
    Collection of utility functions.

    • Constructor Summary

      Constructors 
      Constructor Description
      HealpixUtils()  

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static boolean approx​(double a, double b, double epsilon)  
      static boolean approx​(float a, float b, float epsilon)  
      static void check​(boolean cond, java.lang.String errtxt)
      Evaluates cond; if it is false, throws an Exception containing errtxt.
      static double cosdist_zphi​(double z1, double phi1, double z2, double phi2)
      Computes the cosine of the angular distance between two z, phi positions on the unit sphere.
      static double cosdist_zphi​(Zphi zp1, Zphi zp2)
      Computes the cosine of the angular distance between two z, phi positions on the unit sphere.
      static double fmodulo​(double v1, double v2)
      Returns the remainder of the division v1/v2.
      static int ilog2​(long arg)
      Integer base 2 logarithm.
      static int isqrt​(long arg)
      Integer square root.
      static long nest2peano​(long pix, int order)  
      static long peano2nest​(long pix, int order)  
      static int uniq2order​(long uniq)  

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • HealpixUtils

        public HealpixUtils()

    • Method Detail

      • check

        public static void check​(boolean cond,
                         java.lang.String errtxt)
                  throws java.lang.Exception
        Evaluates cond; if it is false, throws an Exception containing errtxt.
        Throws:
        java.lang.Exception

      • ilog2

        public static int ilog2​(long arg)
        Integer base 2 logarithm.
        Parameters:
        arg -
        Returns:
        the largest integer n that fulfills 2^n<=arg. For negative arguments and zero, 0 is returned.

      • isqrt

        public static int isqrt​(long arg)
        Integer square root.
        Parameters:
        arg -
        Returns:
        the integer n which fulfills n^2<=arg<(n+1)^2

      • cosdist_zphi

        public static double cosdist_zphi​(double z1,
                                  double phi1,
                                  double z2,
                                  double phi2)
        Computes the cosine of the angular distance between two z, phi positions on the unit sphere.

      • cosdist_zphi

        public static double cosdist_zphi​(Zphi zp1,
                                  Zphi zp2)
        Computes the cosine of the angular distance between two z, phi positions on the unit sphere.

      • fmodulo

        public static double fmodulo​(double v1,
                             double v2)
        Returns the remainder of the division v1/v2. The result is non-negative.
        Parameters:
        v1 - dividend; can be positive or negative
        v2 - divisor; must be positive
        Returns:
        remainder of the division; positive and smaller than v2

      • approx

        public static boolean approx​(float a,
                             float b,
                             float epsilon)

      • approx

        public static boolean approx​(double a,
                             double b,
                             double epsilon)

      • uniq2order

        public static int uniq2order​(long uniq)

      • nest2peano

        public static long nest2peano​(long pix,
                              int order)

      • peano2nest

        public static long peano2nest​(long pix,
                              int order)