<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">今天主要寫寫怎麼用Visual Studio在Excel裡面做圖（chart），網上有很多人都討論過這個問題，但我覺得這裡還是寫一下C# for financial markets裡面怎麼寫的，因為我覺得這個做出來的比較好。</span>

首先看一下chart在excel裡面的結構位置：

這裡作圖主要用的就是ChartWizard，但是我剛開始做出來的圖巨醜無比。。。而且還不對，不知道為什麼，型別已經設定成XY散點圖，但是畫出來還是這幅尿性。。

後來經過書中的提示，我實現了這個函式，於是duang地一下，做出來了一張很唯美的chart！！！

// Excel作圖  【更新】2015/3/10 
        public void CreateChart<T>(Vector<T> x, Vector<T> y, string title, string horizontal, string vertical, string legend)
        {
            try
            {
                // Add sheet.
                Excel.Workbook pWorkbook;
                Excel.Worksheet pSheet;
                if (pExcel.ActiveWorkbook == null)
                {
                    pWorkbook = (Excel.Workbook)InvokeMethodInternational(pExcel.Workbooks, "Add", Excel.XlWBATemplate.xlWBATWorksheet);
                    pSheet = (Excel.Worksheet)pWorkbook.ActiveSheet;
                }
                else
                {
                    pWorkbook = pExcel.ActiveWorkbook;
                    pSheet = (Excel.Worksheet)InvokeMethodInternational(pWorkbook.Worksheets, "Add", Type.Missing, Type.Missing, 1, Type.Missing);
                }
                // Add row labels + values.
                int sheetColumn = 1;
                int sheetRow = 1;
                //列印X列
                ToSheetVertical(pSheet, sheetRow, sheetColumn, horizontal, x);
                //列印Y列
                ToSheetVertical(pSheet, sheetRow, sheetColumn + 1, vertical, y);

                // 在工作簿中增加圖表Chart（XY點圖）
                Excel.Chart chart = pWorkbook.Charts.Add(Type.Missing, Type.Missing, Type.Missing, Type.Missing) as Excel.Chart;
                Excel.Range range = (Excel.Range)pSheet.get_Range("A2","B" + (x.Length+1).ToString() );
                chart.ChartWizard(range, Excel.XlChartType.xlXYScatterLinesNoMarkers, 1, Excel.XlRowCol.xlColumns, 1, 0, true, title, horizontal, vertical, Type.Missing);
                chart.SeriesCollection(1).Name = legend;
            }
            catch (Exception e)
            {
                Console.WriteLine("Exception: " + e);
            }
        
        }
 

 class test
    {
            static void Main(string[] args)
        {
            Vector<double> t = new Vector<double>(new double[] { 0.1, 1, 4, 9, 20, 30 }, 0);
            Vector<double> r = new Vector<double>(new double[] { 0.081, 0.07, 0.044, 0.07, 0.04, 0.03 }, 0);
            LinearInterpolator myInterpolatorH = new LinearInterpolator(t, r);
            // Create the abscissa values f (hard-coded for the moment)
            int M = 299;
            Vector<double> term = new Vector<double>(M, 1);
            term[term.MinIndex] = 0.1;
            double step = 0.1;
            for (int j = term.MinIndex + 1; j <= term.MaxIndex; j++)
            {
                term[j] = term[j - 1] + step;
            }
            Vector<double> interpolatedlinear = myInterpolatorH.Curve(term);        
            ExcelMechanisms exl = new ExcelMechanisms();
            exl.printOneExcel<double>(term, interpolatedlinear, "Linear Interpolated Curve", "time", "Interest Rate", "Interpolated Interest Rate");
                
            Console.Read();
        }
 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace UserDefinedDataEXP
{
    //點列
    public class Pair <T>
    { 
        public T first;
        public T second;

        public Pair (T First, T Second)
        {
            this.first = First;
            this.second = Second;
        }
    }

    //雙線插值
    public class BilinearInterpolator
    {
        private Vector<double> x1Arr;
        private Vector<double> x2Arr;
        private NumericMatrix<double> matVals;
        private int N1;
        private int N2;

        //找出x1Arr中小於或者等於x的index
        //找出x2Arr中小於或者等於y的index
        public Pair<int> findAbscissa (double x,double y)
        {
            int firstIndex = 0;
            int secondIndex = 0;
            for (int i = 0; i <= N1-1; i++)
            {
                if (x1Arr[i]<=x && x<=x1Arr[i+1])
                {
                    for (int j = 0; j <= N2 - 1; j++)
                    {
                        if (x2Arr[j] <= y && y <= x2Arr[j + 1])
                        {
                            return new Pair<int>(firstIndex, secondIndex);
                        }
                        secondIndex++;
                    }
                }
                firstIndex++;
            }
            return null;
        }

        //構造器
        public BilinearInterpolator(Vector<double> x1arr, Vector<double> x2arr, NumericMatrix<double> gridValues)
        {
            this.x1Arr = x1arr;
            this.x2Arr = x2arr;
            N1 = x1arr.Length - 1;
            N2 = x2arr.Length - 1;
            matVals = gridValues;
        }

        //返回(x,y)上的值！
        public double Solve(double x, double y)
        {
            Pair<int> p = findAbscissa(x, y);
            int i = p.first;
            int j = p.second;
            // 4 box points, create variables for readability (see Wiki)
            double Q11 = matVals[i, j]; double Q22 = matVals[i + 1, j + 1];
            double Q12 = matVals[i, j + 1]; double Q21 = matVals[i + 1, j];
            double x1 = x1Arr[i]; double x2 = x2Arr[i + 1];
            double y1 = x2Arr[j]; double y2 = x2Arr[j + 1];
            double factor = 1.0 / ((x2 - x1) * (y2 - y1));
            return (Q11 * (x2 - x) * (y2 - y) + Q21 * (x - x1) * (y2 - y) + Q12 * (x2 - x) * (y - y1) + Q22 * (x - x1) * (y - y1)) * factor;
        }

        //根據輸入的(x,y)點列集，給出插值後的Surface
        public NumericMatrix<double> Surface(Vector<double> x1arr, Vector<double> x2arr)
        { 
            NumericMatrix<double> result=new NumericMatrix<double>(x1arr.Length, x1arr.Length);
            for (int i = x1arr.MinIndex; i <= x1arr.MaxIndex; i++)
            {
                for (int j = x2arr.MinIndex; j <= x2arr.MaxIndex; j++)
                {
                    result[i, j] = Solve(x1arr[i], x2arr[j]);
                }
            }
            return result;
        }

        public NumericMatrix<double> Surface()
        { // Create the interpolated surface, MEMBER DATA AS ABSCISSAE
            return Surface(x1Arr, x2Arr);
        }
    }

    // LinearInterpolator【更新】2015/3/10
    public class LinearInterpolator
    {
        public Vector<double> t;
        public Vector<double> observedRate;

        public LinearInterpolator(Vector<double> t, Vector<double> ObservedRate)
        {
            this.t = t;
            this.observedRate = ObservedRate;
        }

        public Vector<double> Curve(Vector<double> term)
        {
            int size = term.Length;
            Vector<double> result = new Vector<double>(term.Length,term.MinIndex);
            for (int i =term.MinIndex ; i <=term.MaxIndex; i++)
            {
                if (term[i]<=t[t.MinIndex])
                {
                    result[i] = observedRate[observedRate.MinIndex];
                }
                else if (term[i]>=t[t.MaxIndex])
                {
                    result[i] = observedRate[observedRate.MaxIndex];
                }
                else
                {
                        for (int j = t.MinIndex; j <=t.MaxIndex-1; j++)
                        {
                            if (term[i] > t[j] && term[i] < t[j + 1]) { result[i] = ((term[i] - t[j + 1]) * observedRate[j] + (t[j] - term[i]) * observedRate[j + 1]) / (t[j] - t[j + 1]); }
                        }
                }   
            }
            return result;
        }
    }
}