Package healpix.essentials
Class HealpixUtils
- java.lang.Object
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- healpix.essentials.HealpixUtils
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public class HealpixUtils extends java.lang.Object
Collection of utility functions.
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Constructor Summary
Constructors Constructor Description HealpixUtils()
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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 divisionv1/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)
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Method Detail
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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
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ilog2
public static int ilog2(long arg)
Integer base 2 logarithm.- Parameters:
arg
-- Returns:
- the largest integer
n
that fulfills2^n<=arg
. For negative arguments and zero, 0 is returned.
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isqrt
public static int isqrt(long arg)
Integer square root.- Parameters:
arg
-- Returns:
- the integer
n
which fulfillsn^2<=arg<(n+1)^2
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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.
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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.
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fmodulo
public static double fmodulo(double v1, double v2)
Returns the remainder of the divisionv1/v2
. The result is non-negative.- Parameters:
v1
- dividend; can be positive or negativev2
- divisor; must be positive- Returns:
- remainder of the division; positive and smaller than
v2
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approx
public static boolean approx(float a, float b, float epsilon)
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approx
public static boolean approx(double a, double b, double epsilon)
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uniq2order
public static int uniq2order(long uniq)
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nest2peano
public static long nest2peano(long pix, int order)
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peano2nest
public static long peano2nest(long pix, int order)
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