Modify a text file: $/q3.java

$/q3.java

class Main {
  static String title=  "CST-112: Quiz #3: ";
  static String author=  "Thomas Jefferson";		
  //	++++ CHANGE author TO YOUR NAME
  
  public static void main(String[] args) {
    System.out.println( title + author );
    
    int many=12;
    int[] a;
    a= new int[many];				// Values
    int[] aa= new int[many];		// Squares of the original values.

//	++++ CHANGE array names (tho & jeff) to YOUR NAME!
    double[] tho= new double[many];		// Deviance from mean: a[i]-mu
    double[] jeff= new double[many];	// Square of deviance: d[i]^2

// [1a.]  Change the String author to contain your own name.
	//			Output the number of vowels [AEIOUaeiou] in the String author.
	int numvowels=0;
	//				++++ ADD YOUR CODE HERE
	
	System.out.println( "[1a.] Number of vowels in String author:  " + numvowels );
	//////////////////////////////////////////////////////////////////

fillI( a, many );				// Fill a[] array with random values. // 
	System.out.print( "Original values:   ");
    showI( a, many );				// Print the array a[].

// [2a.]  Add one to every odd value in the array a[].
	//				++++ ADD YOUR CODE HERE

// [2b.]  Determine the "range" of values in the a[] array (lowest to highest); print it.
	//				++++ ADD YOUR CODE HERE
	
	
	// [2c.]  Exchange the highest and lowest values within the array.
	//				(i.e. "swap" the two elements!)
	//				++++ ADD YOUR CODE HERE
	
	
    // [2d.]  Fill the int array, aa[], with the squares of the original values, in a[].
	//				++++ ADD YOUR CODE HERE

// Print both arrays.
	System.out.print( "Modified values:   ");
    showI( a, many );
	System.out.print( "Array of squares:  ");
    showI( aa, many );
	//////////////////////////////////////////////////////////////////
	
	
	
	// [3a.]  Calculate the mean average of the values (using your sumI() method);
	//    assign it to a variable named "mu" and print it.
	//				++++ ADD YOUR CODE OWN CODE BELOW, in the sumI() function.

double mu=  (double) sumI(a, many) / many;
  	System.out.printf( "[3a.]  mu:  %6.2f\n", mu );

// [3b.]  Count how many values are smaller than mu & how many are larger than mu; print these results.    
	int smaller=0, larger=0;
	//				++++ ADD YOUR CODE HERE

if (smaller>0)	say( "[3b.] Number of values smaller than mu:  " + smaller );
	if (larger>0)	say( "[3b.] Number of values larger than mu:  " + larger );

// [3c.]  Fill the array of "deviations" by subtracting mu from each value.
  	//				++++ ADD YOUR CODE HERE
	
	
	prompt( "[3c.]  Deviations:");
    showD( tho, many );

// [3d.]  Compute the sum of the "deviations"; print it.
	//				++++ ADD YOUR CODE OWN CODE BELOW, in the sumD() function.
  	
	double sumd=  sumD( tho, many );
  	System.out.println( "[3d.]  sumd:  " + sumd  );
  	
  	
  	
  	// [3e.]  Fill the double[] dd array with the squares of the deviations.
	//				++++ ADD YOUR CODE HERE

System.out.print( "[3e.]  Dev-squared:");
    showD( jeff, many );
	//////////////////////////////////////////////////////////////////

//// Variance and sigma (standard-deviation). ////
	double variance=0, sigma=0;
  	
  	// [4a.]  Calculate variance = mean average of jeff[].
  	//				(Mean of squares of deviations).
	//				++++ ADD YOUR CODE HERE

System.out.println( "[4a.]  variance:  " + variance );

// [4b.]  Calculate sigma = square-root of the variance.
	//				++++ ADD YOUR CODE HERE

System.out.println( "[4b.]  sigma:  " + sigma );
	//////////////////////////////////////////////////////////////////

//// "Shortcut method" ////
  	double ss=0;
	double vv2=0;
	double shortcut=0;
  	
  	// [5a.]  Find the mean of aa[] ("array of squares");
	// 				store this total in a variable named "ss" ("sum of the squares").
	//				++++ ADD YOUR CODE HERE

System.out.println( "[5a.]  Mean average of the squares in aa[]:  " + ss );
	
	
	//  [5b.]  Subtract the square of mu from ss; store the result in vv2.
	//				++++ ADD YOUR CODE HERE

System.out.println( "[5b.]  ss - mu^2:  " + vv2 );
	
	
	// [5c.]  Set shortcut equal to the square-root of vv2.

System.out.println( "[5c.]  shortcut:  " + shortcut );

// [5d.]  Check whether or not sigma2 and sigma2 are equal;  if not, then print the percentage difference between them.
	double difference=  shortcut - sigma;
	double pct=  difference / sigma;
    if (shortcut == sigma) {
		    System.out.println( "[5d.]  shortcut == sigma" );
    }
    else {
		    System.out.println( "[5d.]  Percentage difference is:  " + pct +"%" );
    }
  }
  //////////////////////////////////////////////////////////////////
  
  
  
  // Sum an array of ints. //
  static double sumI( int a[], int m ) {
  	int total=0;
	//				++++ ADD YOUR CODE HERE
 
  	return total;
  }
  // Sum an array of doubles. //
  static double sumD( double d[], int m ) {
  	double total=0;
	//				++++ ADD YOUR CODE HERE
 
  	return total;
  }

//// THESE FUNCTIONS ARE SUPPLIED WITH THE SAMPLE CODE ////
  //				(No changes are needed below.)
  
  // Fill array with original values. //
  static void fillI( int[] a, int m ) {
  	for (int i=0; i<m; ++i) {
  			int k=  (int) (11 * Math.random());
  			a[i]=  50 + 5 * k;
  	}
  }
  // Print an array of int values. //
  static void showI( int[] a, int m ) {
  	for (int i=0; i<a.length; ++i) {
 	  	System.out.printf( "%3d   ", a[i] );
  	}
  	System.out.println( );
  }
  // Print an array of double values. //
  static void showD( double[] a, int m ) {
  	for (double e: a) {
  		System.out.printf( "%5.2f ", e );
  	}
  	System.out.println( );
  }
  // Output a String to stdin //
  static void say( String s ) { System.out.println( s ); }	// Print a line.
  static void prompt( String s ) { System.out.print( s ); }	// Print on same line.
}//END OF class Main//