DasMath

java.lang.Object
- org.das2.util.DasMath

public class DasMath
extends java.lang.Object

Constructor Summary

Constructors
Constructor and Description

DasMath()
Creates a new instance of DasMath

Constructors
Constructor and Description
`DasMath()` Creates a new instance of DasMath

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static double`	`biggerOf(double x1, double x2)` returns the bigger number of two numbers
`static double`	`exp10(double x)`
`static double`	`exp10(int x)`
`static double[]`	`findex(double[] datax, double[] x)` Returns the "floating point indeces" of x within array datax.
`static double`	`findex(double[] datax, double x, int guess)`
`static double`	`gcd(double[] A, double error)` Returns the greatest common divisor of a group of numbers.
`static double`	`interpolate(double[] datay, double findex)` Interpolate just one point
`static double[]`	`interpolate(double[] datay, double[] findex)` interpolate an array of points.
`static double`	`log10(double x)`
`static void`	`main(java.lang.String[] args)`
`static double`	`max(double[] A)` return the maximum of the list
`static double`	`mean(double[] A)` return the mean of the list.
`static double`	`median(double[] A)` return the median of the list length N, which is the value at index N/2 of the sorted list.
`static double`	`min(double[] A)` return the minimum of the list
`static double`	`modp(double x, double t)` just like modulo (%) function, but negative numbers return positive phase.
`static int`	`modp(int x, int t)` just like modulo (%) function, but negative numbers return positive phase.
`static double`	`roundNFractionalDigits(double x, int n)` round the decimal to the number of fractional decimal places.
`static double`	`roundNSignificantDigits(double x, int n)` Round the double to n significant digits by removing the exponent to make the number order one, then rounding the mantissa, then replacing the exponent.
`static double[]`	`sort(double[] A)` return a sorted version of the array.
`static double`	`tanh(double x)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - DasMath
```
public DasMath()
```
    Creates a new instance of DasMath
- Method Detail
  - log10
```
public static double log10(double x)
```
  - exp10
```
public static double exp10(double x)
```
  - exp10
```
public static double exp10(int x)
```
  - roundNFractionalDigits
```
public static double roundNFractionalDigits(double x,
                                            int n)
```
    round the decimal to the number of fractional decimal places. For example, DasMath.roundNFractionalDigits(1.2345678,3)==1.23 Note the name implies that there will be three decimals in the fractional part, but this implementation will return only two.
    
    Parameters:
    
    x - a double
    
    n - number of decimal places
    
    Returns:
    
    the number rounded to the number of decimal places.
    
    See Also:
    
    roundNSignificantDigits(double, int), https://github.com/autoplot/dev/blob/master/demos/2023/20230910/roundNDigits.jy
  - roundNSignificantDigits
```
public static double roundNSignificantDigits(double x,
                                             int n)
```
    Round the double to n significant digits by removing the exponent to make the number order one, then rounding the mantissa, then replacing the exponent.
    
    Parameters:
    
    x - a double
    
    n - number of decimal places
    
    Returns:
    
    the number rounded to the number of decimal places.
    
    See Also:
    
    roundNFractionalDigits(double, int), https://github.com/autoplot/dev/blob/master/demos/2023/20230910/roundNDigits.jy
  - tanh
```
public static double tanh(double x)
```
  - interpolate
```
public static double interpolate(double[] datay,
                                 double findex)
```
    Interpolate just one point
  - interpolate
```
public static double[] interpolate(double[] datay,
                                   double[] findex)
```
    interpolate an array of points.
  - findex
```
public static double[] findex(double[] datax,
                              double[] x)
```
    Returns the "floating point indeces" of x within array datax. A floating point index (or "findex") indicates the indeces of the points that bracket and the weights of each bracketing point to use. A findex of 4.5 indicates that x is half-way between index 4 and 5, so equal weights should be used. floor( findex ) is the "left" bracket, ceil(findex) is the "right" bracket, and fp( findex ) is the weight for the right bracket. See interpolate for an example of its use.
  - findex
```
public static final double findex(double[] datax,
                                  double x,
                                  int guess)
```
  - main
```
public static void main(java.lang.String[] args)
```
  - modp
```
public static double modp(double x,
                          double t)
```
    just like modulo (%) function, but negative numbers return positive phase.
    
    Parameters:
    
    x - the numerator
    
    t - the devisor
    
    Returns:
    
    the modulo, which will always be positive
  - modp
```
public static int modp(int x,
                       int t)
```
    just like modulo (%) function, but negative numbers return positive phase.
    
    Parameters:
    
    x - the numerator
    
    t - the devisor
    
    Returns:
    
    the modulo, which will always be positive
  - biggerOf
```
public static double biggerOf(double x1,
                              double x2)
```
    returns the bigger number of two numbers
    
    Parameters:
    
    x1 - a number
    
    x2 - a number
    
    Returns:
    
    the greater of the two numbers
  - gcd
```
public static double gcd(double[] A,
                         double error)
```
    Returns the greatest common divisor of a group of numbers. This is useful for a number of visualization techniques, for instance when you need to integerize your data, the binsize should be the gcd. An error parameter is provided to avoid numerical noise, and in case there is a granularity that needn't be surpassed. org.das2.datum.DatumUtil has a private copy of this code.
    
    Parameters:
    
    A - the array of numbers
    
    error - the limit of the error to deal with numerical noise
    
    Returns:
    
    the greatest common divisor (GCD)
  - mean
```
public static double mean(double[] A)
```
    return the mean of the list. The first element's magnitude is removed from each accumulated value so that items with large offset values (for example times) can be averaged. There is no checking for NaNs or fill values.
    
    Parameters:
    
    A -
    
    Returns:
    
    the mean of the list.
  - median
```
public static double median(double[] A)
```
    return the median of the list length N, which is the value at index N/2 of the sorted list. This does not return the average for even-length lists. and there is no checking for NaNs or fill values.
    
    Parameters:
    
    A - the list of numbers
    
    Returns:
    
    the median of the list
  - max
```
public static double max(double[] A)
```
    return the maximum of the list
    
    Parameters:
    
    A - the list of numbers
    
    Returns:
    
    the maximum of the list
  - min
```
public static double min(double[] A)
```
    return the minimum of the list
    
    Parameters:
    
    A - the list
    
    Returns:
    
    the minimum of the list
  - sort
```
public static double[] sort(double[] A)
```
    return a sorted version of the array. The original array is not modified.
    
    Parameters:
    
    A -
    
    Returns:
    
    return a sorted version of the array.

Class DasMath

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

DasMath

Method Detail

log10

exp10

exp10

roundNFractionalDigits

roundNSignificantDigits

tanh

interpolate

interpolate

findex

findex

main

modp

modp

biggerOf

gcd

mean

median

max

min

sort