java生成随机vector
时间: 2024-01-22 22:16:13 浏览: 26
以下是Java生成随机Vector的示例代码:
```java
import java.util.Vector;
import java.util.Random;
public class RandomVectorGenerator {
public static void main(String[] args) {
Vector<Integer> vector = new Vector<>();
Random random = new Random();
// 生成随机Vector
for (int i = 0; i < 10; i++) {
vector.add(random.nextInt(100));
}
// 打印随机Vector
System.out.println("随机Vector: " + vector);
}
}
```
这段代码使用了Java的`Vector`类和`Random`类。首先创建一个`Vector`对象,然后使用`Random`类生成随机数,并将随机数添加到`Vector`中。最后打印出生成的随机`Vector`。
相关问题
java 克里金插值并生成空间热力图
克里金插值是一种空间内插方法,可以用于通过已知数据点的空间位置和对应数值,推断未知位置处的数值。在生成空间热力图时,可以使用克里金插值来估算每个网格点的数值,然后使用颜色渐变来表示不同数值的大小。
以下是用Java实现克里金插值并生成空间热力图的简单步骤:
1. 获取已知数据点的空间位置和对应数值,存储在一个列表中。
2. 定义网格的大小和分辨率,并将空间范围划分成网格。
3. 对于每个网格点,使用克里金插值算法来估算其数值。
4. 根据估算的数值,使用颜色渐变来表示不同数值的大小,生成空间热力图。
以下是一个简单的示例代码,其中使用了Apache Commons Math库来实现克里金插值算法和颜色渐变:
```java
import org.apache.commons.math3.analysis.interpolation.KrigingInterpolator;
import org.apache.commons.math3.analysis.interpolation.LinearInterpolator;
import org.apache.commons.math3.analysis.interpolation.SplineInterpolator;
import org.apache.commons.math3.analysis.interpolation.TriangulatedInterpolatingFunction;
import org.apache.commons.math3.analysis.interpolation.Triangulator;
import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;
import org.apache.commons.math3.util.FastMath;
import org.apache.commons.math3.util.MathArrays;
import javax.swing.*;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import java.util.List;
public class HeatmapPanel extends JPanel {
private static final int GRID_SIZE = 50;
private static final int GRID_RESOLUTION = 10;
private static final double RADIUS = 0.2;
private List<Vector3D> dataPoints;
private double[][] gridValues;
private BufferedImage heatmapImage;
public HeatmapPanel() {
setPreferredSize(new Dimension(800, 600));
setBackground(Color.WHITE);
// Generate random data points
dataPoints = new ArrayList<>();
for (int i = 0; i < 100; i++) {
double x = Math.random() * 10;
double y = Math.random() * 10;
double z = Math.random() * 100;
dataPoints.add(new Vector3D(x, y, z));
}
// Compute grid values using Kriging interpolation
KrigingInterpolator interpolator = new KrigingInterpolator();
Triangulator triangulator = new Triangulator();
TriangulatedInterpolatingFunction triangulatedInterpolation = new TriangulatedInterpolatingFunction(dataPoints, triangulator, interpolator);
gridValues = new double[GRID_SIZE][GRID_SIZE];
for (int i = 0; i < GRID_SIZE; i++) {
for (int j = 0; j < GRID_SIZE; j++) {
double x = i * 1.0 / GRID_RESOLUTION;
double y = j * 1.0 / GRID_RESOLUTION;
double z = triangulatedInterpolation.value(new Vector3D(x, y, 0));
gridValues[i][j] = z;
}
}
// Generate heatmap image
heatmapImage = new BufferedImage(GRID_SIZE, GRID_SIZE, BufferedImage.TYPE_INT_RGB);
double[] values = MathArrays.flatten(gridValues);
double minValue = MathArrays.min(values);
double maxValue = MathArrays.max(values);
for (int i = 0; i < GRID_SIZE; i++) {
for (int j = 0; j < GRID_SIZE; j++) {
double value = gridValues[i][j];
int colorValue = (int) FastMath.round(255 * (value - minValue) / (maxValue - minValue));
Color color = new Color(colorValue, 0, 255 - colorValue);
heatmapImage.setRGB(i, GRID_SIZE - j - 1, color.getRGB());
}
}
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
// Draw heatmap image
Graphics2D g2d = (Graphics2D) g;
AffineTransform transform = new AffineTransform();
transform.scale(getWidth() * 1.0 / GRID_SIZE, getHeight() * 1.0 / GRID_SIZE);
g2d.drawImage(heatmapImage, transform, null);
// Draw data points
for (Vector3D point : dataPoints) {
int x = (int) FastMath.round(point.getX() * GRID_RESOLUTION);
int y = (int) FastMath.round((1 - point.getY()) * GRID_RESOLUTION);
int radius = (int) FastMath.round(RADIUS * GRID_RESOLUTION);
g2d.setColor(Color.BLACK);
g2d.drawOval(x - radius, y - radius, 2 * radius, 2 * radius);
}
}
public static void main(String[] args) {
JFrame frame = new JFrame("Heatmap");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new HeatmapPanel());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
```
运行该代码将会生成一个随机数据点的空间热力图,其中使用了Kriging插值算法来估算每个网格点的数值。在绘制热力图时,使用了颜色渐变来表示不同数值的大小,并且在数据点周围绘制了黑色圆圈以便于观察。你可以根据自己的需求,修改代码来适应不同的数据点或插值算法。
aes 256 OFB java实现
下面是AES 256 OFB模式的Java实现示例:
```java
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
public class AESOFBExample {
public static void main(String[] args) throws Exception {
String plainText = "This is a secret message";
System.out.println("Plain Text: " + plainText);
// Generate a 256-bit AES key
KeyGenerator keyGen = KeyGenerator.getInstance("AES");
keyGen.init(256);
SecretKey secretKey = keyGen.generateKey();
byte[] keyBytes = secretKey.getEncoded();
// Generate a random initialization vector
SecureRandom random = new SecureRandom();
byte[] ivBytes = new byte[16];
random.nextBytes(ivBytes);
// Create the Cipher object and configure it for OFB mode with AES encryption
Cipher cipher = Cipher.getInstance("AES/OFB/PKCS5Padding");
SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");
IvParameterSpec ivSpec = new IvParameterSpec(ivBytes);
cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivSpec);
// Encrypt the plain text
byte[] encryptedBytes = cipher.doFinal(plainText.getBytes());
System.out.println("Encrypted Text: " + new String(encryptedBytes));
// Decrypt the encrypted text
cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);
byte[] decryptedBytes = cipher.doFinal(encryptedBytes);
System.out.println("Decrypted Text: " + new String(decryptedBytes));
}
}
```
上述代码中,我们首先使用Java的`KeyGenerator`类生成一个256位的AES密钥。然后,我们使用`SecureRandom`类生成一个随机的16字节的初始化向量。
接下来,我们创建一个`Cipher`对象,并将其配置为使用AES加密的OFB模式。然后,我们使用生成的密钥和初始化向量初始化`Cipher`对象,并使用`doFinal`方法对明文进行加密。
最后,我们再次使用相同的密钥和初始化向量初始化`Cipher`对象,并使用`doFinal`方法对密文进行解密。