• 用Microsoft.Solver.Foundation进行线性规划,为WPF应用添加智能


      在管理信息系统的开发过程中,往往会涉及到一些线性规划数学模型,例如资源配置优化。微软的Microsoft.Solver.Foundation是一个数学库,可以很好的对线性规划问题进行求解。关于它的细节,可以自行百度,话不多说,以例题来学习如何用Microsoft.Solver.Foundation进行线性规划:

      题目(来自网络),如下图:

      

      为了解决上述线性规划问题,先要下载并安装Microsoft.Solver.Foundation库,关于安装细节这里不赘述。

    1、VS2012建立一个WPF应用程序WpfLPDemo(WinForm也是可以的),新建一个libs文件夹和images文件夹,并将Microsoft.Solver.Foundation.dll拷贝到libs(注意添加dll引用),如下图:

    images下放的图片为题目截图。

    2、编辑MainWindow.xaml文件,在设计界面上放一个Image展示例题截图、TextBlock用于显示优化结果、Button用于触发计算事件,代码如下:

     1 <Window x:Class="WpfLPDemo.MainWindow"
     2         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
     3         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     4         Title="MainWindow" Height="424.03" Width="711.269">
     5     <Grid>
     6         <Image HorizontalAlignment="Left" Height="290" Margin="4,10,0,0" VerticalAlignment="Top" Width="695" Source="images/1.png"  Stretch="Fill" />
     7         <TextBlock Name="answer" HorizontalAlignment="Left" Margin="33,352,0,0" TextWrapping="Wrap"  VerticalAlignment="Top"  Text="线性规划答案为:" FontFamily="Verdana" FontSize="14"  />
     8         <Button Content="计算" HorizontalAlignment="Left" Margin="604,305,0,0" VerticalAlignment="Top" Width="75"  Click="Button_Click_calc"  FontSize="15" />
     9 
    10     </Grid>
    11 </Window>

    3、编辑MainWindow.xaml.cs文件,注意添加using Microsoft.SolverFoundation.Services; using Microsoft.SolverFoundation.Solvers;代码如下(核心代码已经做了注释,可了解一下用法):

     1 using System;
     2 using System.Collections.Generic;
     3 using System.Linq;
     4 using System.Text;
     5 using System.Threading.Tasks;
     6 using System.Windows;
     7 using System.Windows.Controls;
     8 using System.Windows.Data;
     9 using System.Windows.Documents;
    10 using System.Windows.Input;
    11 using System.Windows.Media;
    12 using System.Windows.Media.Imaging;
    13 using System.Windows.Navigation;
    14 using System.Windows.Shapes;
    15 using Microsoft.SolverFoundation;
    16 namespace WpfLPDemo
    17 {
    18     using Microsoft.SolverFoundation.Services;
    19     using Microsoft.SolverFoundation.Solvers;
    20     /// <summary>
    21     /// MainWindow.xaml 的交互逻辑
    22     /// </summary>
    23     public partial class MainWindow : Window
    24     {
    25         public MainWindow()
    26         {
    27             InitializeComponent();         
    28         }
    29         public object OPT()
    30         {
    31             SolverContext context = SolverContext.GetContext();
    32             //创建模型
    33             Model model = context.CreateModel();
    34             //优化决策因子,变量为实数,Domain.Integer|Domain.IntegerNonnegative为整数优化
    35             Decision x = new Decision(Domain.Real, "x");   
    36             Decision y = new Decision(Domain.Real, "y");
    37             //添加
    38             model.AddDecisions(x, y);
    39             //x,y变量范围
    40            // model.AddConstraints("变量范围",
    41            // double.NegativeInfinity < x <= double.PositiveInfinity,
    42            //double.NegativeInfinity < y <= double.PositiveInfinity);
    43 
    44             model.AddConstraints("约束",
    45             double.NegativeInfinity < x <= double.PositiveInfinity,
    46            double.NegativeInfinity < y <= double.PositiveInfinity,
    47             2*x +  y     - 2    >=0,
    48             x     -  2*y  + 4   >=0,
    49            3*x -   y      -3    <= 0);
    50             //目标函数 min z=x * x + y * y , GoalKind.Minimize最小值
    51            Goal gmin= model.AddGoal("zmin", GoalKind.Minimize, x * x + y * y);
    52         
    53             //优化
    54             Solution solution = context.Solve();
    55             //优化报告
    56            // Report report = solution.GetReport();
    57 
    58             string s = string.Format("min [ x={0:N2},y={1:N2}", x.ToDouble().ToString("0.00"), y.ToDouble().ToString("0.00"));
    59             s += string.Format(",min={0} ] " ,solution.Goals.First<Goal>().ToDouble().ToString("0.00"));
    60           
    61             //=================================================================
    62             model.RemoveGoal(gmin);
    63             Goal gmax = model.AddGoal("zmax", GoalKind.Maximize, x * x + y * y);
    64             //优化
    65              solution = context.Solve();
    66              s += string.Format("| max[ x={0:N2},y={1:N2}", x.ToDouble().ToString("0.00"), y.ToDouble().ToString("0.00"));
    67              s += string.Format(",max={0} ] " ,solution.Goals.First<Goal>().ToDouble().ToString("0.00"));
    68             //--------------------------------------------------------------------------------------------------------------------------------
    69 
    70             context.ClearModel();
    71             return s;
    72 
    73         }
    74         private void Button_Click_calc(object sender, RoutedEventArgs e)
    75         {
    76             this.answer.Text = OPT().ToString();
    77         }
    78 
    79        
    80     }
    81 }

    4、保存并运行程序,成功的话应该如下图:

    5、单击计算按钮,即可输出结构,如下图:

    可见计算的答案和例题给出的答案是一致的。为了构建根据通用的程序,可以从UI上动态传入模型以及模型的值进行优化求解,从而更好的具有实用性。

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  • 原文地址:https://www.cnblogs.com/isaboy/p/linearprogram.html
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