Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 11

[beer1214]

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 11
at DataSet.<init>(DataSet.java:50)
at DataSetClient.main(DataSetClient.java:43)

This is the error I keep getting with my code It is arrays and constructors being used, I cant find the error to correct it. I am using Eclipse by the way below is my main and my constructor class.

import java.util.Arrays;
import java.util.Random;
public class DataSetClient
{
public static void main(String[] args)
{
Random generator = new Random();

double[] randomData = new double[ generator.nextInt(4) + 10 ];
for (int index = 0; index < randomData.length; index++)
randomData[index] = Math.round(generator.nextDouble() * 10000) / 100.0;

System.out.println("============ Arrays Demo ================================");
double[] sortedData = Arrays.copyOf(randomData, randomData.length);
Arrays.sort( sortedData );

System.out.println( "Random\n" + Arrays.toString(randomData) );
System.out.println( "Sorted\n" + Arrays.toString(sortedData) );
System.out.println();

System.out.println("============ DataSet Test ================================");
DataSet analyzer = new DataSet( randomData );
System.out.println(analyzer.size() + " Data Items");
System.out.println( Arrays.toString( analyzer.getData() ) );
System.out.println( "Minimum: " + analyzer.minimum() +
" at index " + analyzer.indexOfMin() );
System.out.println( "Maximum: " + analyzer.maximum() +
" at index " + analyzer.indexOfMax() );
System.out.println( "Data Range: " + analyzer.range() );
System.out.println( "Median : " + analyzer.median() );
System.out.println( "Mean : " + analyzer.mean() );
System.out.println( "Variance : " + analyzer.variance() );
System.out.println( "Std Dev : " + analyzer.standardDeviation() );

}

}


import java.util.Arrays;
public class DataSet
{
//Instance Data
private double[] data;
private int indexMax = 0;
private double maximum = 0.0;
private int indexMin = 0;
private double minimum = 0.0;
private double median = 0.0;
private double mean = 0.0;
private double variance = 0.0;

//Constructor: Create a new DataSet
// Parameter : data points to be included into this DataSet
// Exception : the number of data points must be at least 2
public DataSet(double[] data)
{
if (data.length < 2)
throw new RuntimeException("Data points must be at least 2");

else
this.data = data;

//find index of max, indexof min and mean
double sum = 0;
for(int i = 0; i < data.length; i++)
{
if(data[i] > data[i+1] )
indexMax = i;

else if(data[i] < data[i+1] )
indexMin = i;

sum = sum + data[i];
}
mean = sum / data.length;


// find median
double[] sortedData = Arrays.copyOf(data, data.length);
Arrays.sort( sortedData );

int medianPosition;
medianPosition = data.length / 2;

median = data[medianPosition];



//Find variance
double difference= 0.0;
for(int in = 0; in < data.length; in++)
{
difference = difference + (data[in] - mean) * (data[in] - mean);

}
variance = difference / data.length;





}

//Return the number of data-points in this DataSet
public int size()
{
return data.length;
}

//Accessor : Return copies of the data-points in this DataSet
public double[] getData()
{
return data;
}

// position of the biggest value
//Return the index of the largest point in this DataSet
public int indexOfMax()
{

return indexMax;
}

//same as indexMas
//Return the value of the largest point in this DataSet
public double maximum()
{

return maximum = data[indexMax];
}

//Return the index of the smallest point in this DataSet
public int indexOfMin()
{
return indexMin;
}

//Return the value of the smallest point in this DataSet
public double minimum()
{
return minimum = data[indexMin];
}

//Return the difference between the largest and smallest
// points in this DataSet
public double range()
{
return maximum - minimum;
}

//Return the value of the median point in this DataSet
public double median()
{
return median;
}

//Return the average value of the points in this DataSet
public double mean()
{
return mean;
}

//difference bettween the item and the mean add them and then divide
//Return the variance of the points in this DataSet
public double variance()
{
return variance;
}

//Return the standard deviation of the points in this DataSet
public double standardDeviation()
{
return variance / variance;
}

}

[GregBrannon]

Please read the Announcement topic to learn how to post code in code or highlight tags and other useful info for newcomers. Please fix your post, if you're allowed. Another thing you should do is post the exact error, copied from as it appears at your end and pasted into a post.

Welcome!

[beer1214]

Thank you I didn't know, I am new to this site and this is my first posting

[andbin]

	      for(int i = 0; i < data.length; i++)
	      {
	           if(data[i] > data[i+1] )
	            indexMax = i;  
 
	           else if(data[i] < data[i+1] )
	            indexMin = i;

the i+1 goes out of bounds (when i reaches the last valid index).

[beer1214]

Thank you, I deleted the +1 and left it as [i] and the program compiles properly now, but is that correct?