Question

for this assignment you will be creating a series of functions for manipulating an array of data. The data will consist of randomly generated doubles. You should make the following functions:

• generate() - This function fills an array with random doubles in a specified range. This function takes four inputs: an array of doubles, an integer representing the size of the array, and two doubles representing the lower an upper bounds of the range random values. For example, the function call:
  generate(data,100,-5.0,5.0);
  should fill the array called data[] with 100 random values between -5.0 and 5.0.
• print() - This function should print an array of values. The function takes two inputs: an array and the size of the array. Exactly how the values are printed is up to you, but its probably best not to print each value on its own line.
• average() - This function returns the average of an array of values. The function takes two inputs: an array and the size of the array, and it returns a double.
• min() This function returns the smallest value from an array of values. The function takes two inputs: an array and the size of the array, and it returns a double.
• max() This function returns the largest value from an array of values. The function takes two inputs: an array and the size of the array, and it returns a double.
• addX() This function adds a value to every element in an array. function takes three inputs: an array, the size of the array, and the value to be added to each element of the array. For example, if you have an array [5.5, 6.6, 7.7] and you call:
  add(array, 3, 2.5)
  the array should become [8, 9.1, 10.2], that is each element had 2.5 added to it.
• num_less() This function returns the number of values that are lower than the average value of an array of values. That is it counts how many values are less than the average and returns that number. The function takes two inputs: an array and the size of the array, and it returns an integer (the number of values below the average).
• num_more() This function returns the number of values that are higher than the average value of an array of values. That is it counts how many values are less than the average and returns that number. The function takes two inputs: an array and the size of the array, and it returns an integer (the number of values above the average).
• num_less() (same name as the function above) This function returns the number of values that are lower than a threshold value in an array of values. That is it counts how many values are less than the threshold value. The threshold value is passed to the function. The function takes three inputs: an array, the size of the array, and a double which is the threshold value. It returns an integer, which is the number of values below the threshold.
• range() This returns the range of values in the array, i.e. the difference between the largest and smallest values in the array. The function takes two inputs: an array and the size of the array. It returns a double, which is the range.
• Extra Credit: std_dev() This function returns the standard deviation of the values in the array. Note in the formula on the linked web page the Greek symbol is mu, which is the average (or mean) of the data. The square root function is defined in the cmath library, which you can include. The function takes two inputs: an array and the size of the array. It returns a double, which is the standard deviation.

Make sure to write a main() function that tests each of the functions. It should use the generate() function to fill the array. If you can't finish all of the functions make a note of which ones you did finish in the code comments.

Answer 1

Thanks for the question, here is the complete code including the extra credit part.

thank you !!

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#include<iostream>
#include <cmath>
#include<cstdlib>

using namespace std;

void generate(double data[], int size, int lower, int upper){
  
   for(int i=0; i<size;i++){
       data[i] = ((double) rand() / (RAND_MAX))*(upper-lower) + lower;
   }  
}

void print(double data[], int size){
   for(int i=0; i<size;i++){
       cout<<data[i]<<" ";
   }
   cout<<endl<<endl;
  
}

double average(double data[], int size){
   double total = 0;
   for(int i=0; i<size;i++){
       total+=data[i];
   }
   return total/size;
}

double min(double data[], int size){
   double min_val=0;
   for(int i=0; i<size; i++){
       if(i==0)min_val=data[0];
       else if(min_val>data[i])min_val=data[i];
       }
  
   return min_val;
}

double max(double data[], int size){
   double max_val=0;
   for(int i=0; i<size; i++){
       if(i==0)max_val=data[0];
       else if(max_val<data[i])max_val=data[i];
       }
  
   return max_val;
}

void addX(double data[], int size, double delta){
   for(int i=0; i<size; i++){
       data[i]+=delta;
      
   }
}

int num_less(double data[], int size){
  
   double avg = average(data,size);
   int count=0;
   for(int i=0; i<size; i++){
       count+=data[i]<avg?1:0;
       }
  
   return count;
}

int num_more(double data[], int size){
  
   double avg = average(data,size);
   int count=0;
   for(int i=0; i<size; i++){
       count+=data[i]>avg?1:0;
       }
  
   return count;
}

int num_less(double data[], int size, double threshold){
  
  
   int count=0;
   for(int i=0; i<size; i++){
       count+=data[i]<threshold?1:0;
       }
  
   return count;
}

double range(double data[], int size){
  
   return max(data,size) - min(data,size);
}

double std_dev(double data[], int size){
   double avg = average(data,size);
   double squared_sum=0;
   for(int i=0; i<size;i++){
       squared_sum   += (data[i]-avg)*(data[i]-avg);
   }
      
   return pow(squared_sum/size,0.5);
}

int main(){
  
   int size=20;
   double data[size];
   generate(data,size,-5.0,5.0);
   print(data,size);
   cout<<"Average: "<<average(data,size)<<endl<<endl;
   cout<<"Min Value: "<<min(data,size)<<endl<<endl;
   cout<<"Max Value: "<<max(data,size)<<endl<<endl;
   addX(data,size,1);
   cout<<"Added 1 to all elements\n\n";
   print(data,size);
   cout<<"Num less than average: "<<num_less(data,size)<<endl<<endl;
   cout<<"Num more than average: "<<num_more(data,size)<<endl<<endl;
   cout<<"Num more than 0: "<<num_less(data,size,0)<<endl<<endl;
   cout<<"Range: "<<range(data,size)<<endl<<endl;
   cout<<"Standard Deviation: "<<std_dev(data,size)<<endl<<endl;
  
}

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