seriously if you could help me i wil be in debt to you forever. I need to calculate area under a curve using provided x and y coordinates which are to be opened from a document called xydata.dat. Here is the data as writtten in the document:
x values y values
20.00 0
20.02 15
20.04 27
20.06 39
20.08 54
20.10 65
20.12 75
20.14 84
20.16 93
20.18 101
20.20 108
20.22 113
20.24 116
20.26 115
20.28 112
20.30 107
20.32 100
20.34 92
20.36 83
20.38 74
20.40 64
20.42 53
20.44 39
20.46 27
20.48 15
20.50 0
Here is the best ive done so far but its rudimentary and i just dont know where to go next
Code:/*Program to take x and y values from a curve and add up the area of the trapezoids they form. input:x values and y values from document processing: 0.5(x1 – x2)(f(x2) + f(x3)) + 0.5(x3 – x2)(f(x2) + f(x3))+.... output: area under the curve (sum of all trapezoids) */ #include <iostream> #include <fstream> #include <iomanip> using namespace std; int main() { ifstream datain; ofstream infoout; int x1,y1,x2,y2; double area; double total=0; datain.open("xydata.dat"); infoout.open("area.dat"); if (!datain.fail()) { datain.ignore(80,'\n'); while (!datain.eof()) { datain>>x1; datain>>y1; datain>>x2; datain>>y2; area = 0.5*(x1-x2)*(y1+y2); infoout<<setw(6)<<fixed<<setprecision(5)<<area<<endl; total = total + area; } infoout<<"\nThe area under the curve is "<<area; } else { cout<<"Error opening file"<<endl; } return 0; }
