Package healpix.essentials

Class HealpixUtils

java.lang.Object
healpix.essentials.HealpixUtils
public class HealpixUtils extends Object
Collection of utility functions.
Author:
Martin Reinecke
Copyright:
2011-2014 Max-Planck-Society

  • Constructor Summary

    Constructors
    Constructor
    Description
    HealpixUtils()
     

  • Method Summary

    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, 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 Details

    • HealpixUtils

      public HealpixUtils()

  • Method Details

    • check

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