StdStats

java.lang.Object
- StdStats

```
public final class StdStats
extends java.lang.Object
```
Standard statistics (library of statistical functions). This class provides methods for computing statistics such as min, max, mean, sample standard deviation, and sample variance.
For additional documentation, see Section 2.2 of "Introduction to Programming in Java: An Interdisciplinary Approach" by Robert Sedgewick and Kevin Wayne.

Method Summary

Methods
Modifier and Type	Method and Description
`static void`	`main(java.lang.String[] args)` Test client.
`static double`	`max(double[] a)` Returns the maximum value in the array a[].
`static double`	`max(double[] a, int lo, int hi)` Returns the maximum value in the subarray a[lo..hi].
`static int`	`max(int[] a)` Returns the maximum value in the array a[].
`static double`	`mean(double[] a)` Returns the average value in the array a[].
`static double`	`mean(double[] a, int lo, int hi)` Returns the average value in the subarray a[lo..hi].
`static double`	`mean(int[] a)` Returns the average value in the array a[].
`static double`	`min(double[] a)` Returns the minimum value in the array a[].
`static double`	`min(double[] a, int lo, int hi)` Returns the minimum value in the subarray a[lo..hi].
`static int`	`min(int[] a)` Returns the minimum value in the array a[].
`static void`	`plotBars(double[] a)` Plots bars (i, a[i]) to standard draw, for i in 0..N-1, where N is the length of a[].
`static void`	`plotLines(double[] a)` Plots line segments connecting points (i, a[i]) to standard draw.
`static void`	`plotPoints(double[] a)` Plots the points (i, a[i]) to standard draw.
`static double`	`stddev(double[] a)` Returns the sample standard deviation in the array a[].
`static double`	`stddev(double[] a, int lo, int hi)` Returns the sample standard deviation in the subarray a[lo..hi].
`static double`	`stddev(int[] a)` Returns the sample standard deviation in the array a[].
`static double`	`stddevp(double[] a)` Returns the population standard deviation in the array a[].
`static double`	`stddevp(double[] a, int lo, int hi)` Returns the population standard deviation in the subarray a[lo..hi].
`static double`	`sum(double[] a)` Returns the sum of all values in the array a[].
`static double`	`sum(double[] a, int lo, int hi)` Returns the sum of all values in the subarray a[lo..hi].
`static int`	`sum(int[] a)` Returns the sum of all values in the array a[].
`static double`	`var(double[] a)` Returns the sample variance in the array a[].
`static double`	`var(double[] a, int lo, int hi)` Returns the sample variance in the subarray a[lo..hi].
`static double`	`var(int[] a)` Returns the sample variance in the array a[].
`static double`	`varp(double[] a)` Returns the population variance in the array a[].
`static double`	`varp(double[] a, int lo, int hi)` Returns the population variance in the subarray a[lo..hi].

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

- Method Detail
  - max
```
public static double max(double[] a)
```
    Returns the maximum value in the array a[]. Returns -infinity if no such value.
  - max
```
public static double max(double[] a,
         int lo,
         int hi)
```
    Returns the maximum value in the subarray a[lo..hi]. Returns -infinity if no such value.
  - max
```
public static int max(int[] a)
```
    Returns the maximum value in the array a[]. Returns Integer.MIN_VALUE if no such value.
  - min
```
public static double min(double[] a)
```
    Returns the minimum value in the array a[]. Returns +infinity if no such value.
  - min
```
public static double min(double[] a,
         int lo,
         int hi)
```
    Returns the minimum value in the subarray a[lo..hi]. Returns +infinity if no such value.
  - min
```
public static int min(int[] a)
```
    Returns the minimum value in the array a[]. Returns Integer.MAX_VALUE if no such value.
  - mean
```
public static double mean(double[] a)
```
    Returns the average value in the array a[]. Returns NaN if no such value.
  - mean
```
public static double mean(double[] a,
          int lo,
          int hi)
```
    Returns the average value in the subarray a[lo..hi]. Returns NaN if no such value.
  - mean
```
public static double mean(int[] a)
```
    Returns the average value in the array a[]. Returns NaN if no such value.
  - var
```
public static double var(double[] a)
```
    Returns the sample variance in the array a[]. Returns NaN if no such value.
  - var
```
public static double var(double[] a,
         int lo,
         int hi)
```
    Returns the sample variance in the subarray a[lo..hi]. Returns NaN if no such value.
  - var
```
public static double var(int[] a)
```
    Returns the sample variance in the array a[]. Returns NaN if no such value.
  - varp
```
public static double varp(double[] a)
```
    Returns the population variance in the array a[]. Returns NaN if no such value.
  - varp
```
public static double varp(double[] a,
          int lo,
          int hi)
```
    Returns the population variance in the subarray a[lo..hi]. Returns NaN if no such value.
  - stddev
```
public static double stddev(double[] a)
```
    Returns the sample standard deviation in the array a[]. Returns NaN if no such value.
  - stddev
```
public static double stddev(double[] a,
            int lo,
            int hi)
```
    Returns the sample standard deviation in the subarray a[lo..hi]. Returns NaN if no such value.
  - stddev
```
public static double stddev(int[] a)
```
    Returns the sample standard deviation in the array a[]. Returns NaN if no such value.
  - stddevp
```
public static double stddevp(double[] a)
```
    Returns the population standard deviation in the array a[]. Returns NaN if no such value.
  - stddevp
```
public static double stddevp(double[] a,
             int lo,
             int hi)
```
    Returns the population standard deviation in the subarray a[lo..hi]. Returns NaN if no such value.
  - sum
```
public static double sum(double[] a)
```
    Returns the sum of all values in the array a[].
  - sum
```
public static double sum(double[] a,
         int lo,
         int hi)
```
    Returns the sum of all values in the subarray a[lo..hi].
  - sum
```
public static int sum(int[] a)
```
    Returns the sum of all values in the array a[].
  - plotPoints
```
public static void plotPoints(double[] a)
```
    Plots the points (i, a[i]) to standard draw.
  - plotLines
```
public static void plotLines(double[] a)
```
    Plots line segments connecting points (i, a[i]) to standard draw.
  - plotBars
```
public static void plotBars(double[] a)
```
    Plots bars (i, a[i]) to standard draw, for i in 0..N-1, where N is the length of a[].
  - main
```
public static void main(java.lang.String[] args)
```
    Test client. Reads an array of real numbers from standard input and prints min, mean, max, and stddev.

Class StdStats

Method Summary

Methods inherited from class java.lang.Object

Method Detail

max

max

max

min

min

min

mean

mean

mean

var

var

var

varp

varp

stddev

stddev

stddev

stddevp

stddevp

sum

sum

sum

plotPoints

plotLines

plotBars

main