# how to print the average of each column of 2d n*m array using java

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Raghav Purankar
how to print the average of each column of 2d n*m array using java
1 Answer(s)      6 years and 6 months ago
Posted in : Java Beginners
```here is my code:

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
public class ReadContents {
public static void main(String[] args) throws IOException {
File file = new File("file1.txt");
List<float[]> list = new ArrayList<float[]>();
Scanner scanner = new Scanner(file).useDelimiter("\n");
while (scanner.hasNext()) {
String[] values = scanner.next().trim().split(" ");
float[] floats = new float[values.length];
for (int i = 0; i < values.length; i++) {
floats[i] = Float.parseFloat(values[i]);
}
list.add(floats);
}
float[][] values = new float[list.size()][];
for (int i = 0; i < list.size(); i++) {
values[i] = list.get(i);
for (int j = 0; j < values[i].length; j++) {
System.out.print(values[i][j] + " ");
}
System.out.println();
}

it prints the content of file.now i want to calculate mean(average) of each column present in the given file having say n*m matrix.
```
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View Answers

May 3, 2011 at 10:47 AM

```import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class ReadContents {
public static void main(String[] args) throws IOException {
float column[] = new float[4];
File file = new File("rfg.txt");
List<float[]> list = new ArrayList<float[]>();
Scanner scanner = new Scanner(file).useDelimiter("\n");
while (scanner.hasNext()) {
String[] values = scanner.next().trim().split(" ");
float[] floats = new float[values.length];
for (int i = 0; i < values.length; i++) {
floats[i] = Float.parseFloat(values[i]);
}
list.add(floats);
}
float[][] values = new float[list.size()][];
for (int i = 0; i < list.size(); i++) {
values[i] = list.get(i);
for (int j = 0; j < values[i].length; j++) {
System.out.print(values[i][j] + " ");
column[j] = column[j] + values[i][j];
}
System.out.println();
}
for (int i = 0; i < column.length; i++) {
System.out.println("Sum of column: "+(i+1)+": "+column[i]);
}
}
}
```

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