使用python绘制图形的最大值

Question

我是python的新手并且有一个问题。我已经想出了如何绘制函数图，但是如何绘制一个指示最大值和最小值的点？这是我的代码，它相信我正确的图表。谢谢。

    import numpy as np  
    import matplotlib.pyplot as plt  
    def graph(formula, x_range):  
        x = np.array(x_range)  
        y = eval(formula)
        plt.plot(x, y)  
        plt.show()

    graph('-x**4 + 508 * x + 40', range(-10, 200))

Answer 1

import java.sql.Array;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Struct;

import oracle.jdbc.OracleCallableStatement;
import oracle.jdbc.OracleConnection;

public class ArrayExampleMain {

  public static void main(String[] args) throws Exception {
    OracleConnection conn = getOracleConnection().unwrap(OracleConnection.class);
    System.out.println("Got Connection.");

    OracleCallableStatement callStmt = null;

    try {
      callStmt = (OracleCallableStatement)conn.prepareCall("{call add_projects(?)}");

      // create array holding values for ProjectType object's properties
      Object[] project1 = new Object[] {"1", "Title 1"};
      Object[] project2 = new Object[] {"2", "Title 2"};

      // each struct is one ProjectType object
      Struct structProject1 = conn.createStruct("PROJECT_TYPE", project1);
      Struct structProject2 = conn.createStruct("PROJECT_TYPE", project2);

      Struct[] structArrayOfProjects = {structProject1, structProject2};

      // array holding two ProjectType objects
      Array arrayOfProjects = conn.createOracleArray("MY_ARRAY", structArrayOfProjects);

      callStmt.setArray(1, arrayOfProjects); 
      callStmt.execute();
      conn.commit();

      System.out.println("Committed.");
    } catch (Exception e) {
      if (conn != null) try { conn.rollback(); } catch (Exception ex) { System.out.println("Rollback failed."); }
      throw e;
    } finally {
      callStmt.close();
      conn.close();
     }
  }

  public static Connection getOracleConnection() throws Exception {
    String driver = "oracle.jdbc.driver.OracleDriver";
    String url = "jdbc:oracle:thin:@YOUR_HOST:orcl";
    String username = "hr";
    String password = "password";

    Class.forName(driver); // load Oracle driver

    Connection conn = DriverManager.getConnection(url, username, password);

    return conn;
  }
}

这样的事情？