static void Main(){
int n=10, N=200;
double[] x = new double[n];
double[] y = new double[n];
int i;
for(i=1; i<n; i++){
x[i]=2*PI*i/(n-1);
y[i]=Sin(x[i]);
WriteLine("{0:g6} {1:g6}",x[i],y[i]);
}
Write("\n\n");
var ls = new lspline(x,y);
double z;
double step=(x[n-1]-x[0])/(N-1);
for(z=x[0],i=0;i<N;z=x[0]+(++i)*step){
WriteLine($"{z} {Sin(z)} {ls.eval(z)}");
}
Write("\n\n");
for(z=x[0],i=0;i<N;z=x[0]+(++i)*step){
WriteLine($"{z} {1-Cos(z)} {ls.integ(z)}");
}
}//Main
static int Main(string[] args)
{
if (args.Length < 3)
{
Console.Error.WriteLine("too few arguments");
return(1);
}
string infile = args[0];
string outfile1 = args[1];
string outfile2 = args[2];
StreamReader instream = new StreamReader(infile);
StreamWriter outstream1 = new StreamWriter(outfile1, append: false);
StreamWriter outstream2 = new StreamWriter(outfile2, append: false);
//Importing the data into vectors
List <double> xlist = new List <double>();
List <double> ylist = new List <double>();
do
{
string line = instream.ReadLine();
if (line == null)
{
break;
}
string[] values = line.Split(' ', '\t');
xlist.Add(Double.Parse(values[0]));
ylist.Add(Double.Parse(values[1]));
} while (true);
int n = xlist.Count;
vector x = new vector(n);
vector y = new vector(n);
for (int i = 0; i <= (n - 1); i++)
{
x[i] = xlist[i];
y[i] = ylist[i];
}
lspline s = new lspline(x, y);
// The linear interpolation
int N = 999;
for (int i = 0; i <= N; i++)
{
double z = (x[n - 1] - x[0]) / N * i + x[0];
double yz = s.eval(z);
outstream1.WriteLine($"{z} \t {yz}");
}
// Intergrating by the linear interpolation
for (int i = 0; i <= N; i++)
{
double z = (x[n - 1] - x[0]) / N * i + x[0];
double area_z = s.integral(z);
outstream2.WriteLine($"{z} \t {area_z}");
}
outstream1.Close();
outstream2.Close();
instream.Close();
return(0);
}