在 Java 中旋转数据和文本的坐标平面
此问题解决了在 y 轴上绘制数据点和旋转标签的挑战数据图。提供的代码定义了绘制数据和标签的基本结构，但遇到了两个困难：
解决问题
为了解决这些问题，让我们重点进行以下修改：
1.旋转坐标平面
我们可以旋转坐标平面以与新原点（蓝色矩形的左下角）对齐，并使用以下代码反转 y 轴：
<code class="java">g2d.translate(leftStartPlotWindow, blueTop);//translate origin to bottom-left corner of blue rectangle g2d.scale(1, -1);//invert the y-axis</code>
2。绘制数据
我们通过将数据乘以标量来调整数据以适合旋转的坐标平面：
<code class="java">double Scalar = blueWidth/maxPlot;
ArrayList<Double> scaledDiffs = new ArrayList<>();
for(int e = 0;e<myDiffs.size();e++){scaledDiffs.add(myDiffs.get(e)*Scalar);}</code>3。旋转 Y 轴标签的文本
要在 y 轴上旋转标签，我们使用以下代码：
<code class="java">g2d.rotate(Math.toRadians(-90), 0, 0);//rotate text 90 degrees counter-clockwise g.drawString(yString, -(height/2)-(yStrWidth/2), yStrHeight); g2d.rotate(Math.toRadians(+90), 0, 0);//rotate text 90 degrees clockwise</code>
完整代码
经过这些调整的修改后的代码应该可以解决以下问题：
DataGUI.java
<code class="java">//... Previous code omitted for brevity
import java.awt.geom.AffineTransform;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.ArrayList;
import java.util.List;
class DataGUI extends JFrame{
//... Previous code omitted for brevity
@Override
public void paint(Graphics g) {
// ... Previous code omitted for brevity
int height = getHeight();
int width = getWidth();
ins = getInsets();
// Obtain data about graphics environment and text
Graphics2D g2d = (Graphics2D) g;
FontMetrics fontMetrics = g2d.getFontMetrics();
String xString = "x-axis Label";
int xStrWidth = fontMetrics.stringWidth(xString);
int xStrHeight = fontMetrics.getHeight();
// Set parameters for the inner rectangle
int hPad = 10;
int vPad = 6;
int testLeftStartPlotWindow = ins.left + 5 + (3 * yStrHeight);
int testInnerWidth = width - testLeftStartPlotWindow - ins.right - hPad;
// Find minimum and maximum values
getMaxMinDiffs();
getMaxPlotVal();
// Determine the maximum number of ticks for the axes
double increment = 5.0;
int numTicks = (int) (maxPlot / increment);
int remainder = testInnerWidth % numTicks;
int leftStartPlotWindow = testLeftStartPlotWindow - remainder;
// Calculate the bottom padding and blue rectangle dimensions
int bottomPad = (3 * xStrHeight) - vPad;
int blueTop = ins.bottom + (vPad / 2) + titleStrHeight;
int blueHeight = height - bottomPad - blueTop;
int blueWidth = blueHeight;
int blueBottom = blueHeight + blueTop;
// Start drawing
// ... Previous code omitted for brevity
// Scale the diffs to fit the window
double Scalar = blueWidth / maxPlot;
List<Double> scaledDiffs = new ArrayList<>();
for (Double myDiff : myDiffs) {
scaledDiffs.add(myDiff * Scalar);
}
// Rotate the graphics context for plotting data
AffineTransform at = g2d.getTransform();
g2d.translate(leftStartPlotWindow, blueTop);
g2d.scale(1, -1);
// Plot the scaled diffs
for (int w = 0; w < scaledDiffs.size(); w++) {
if (w > 0) {
double prior = scaledDiffs.get(w - 1);
int priorInt = (int) prior;
double current = scaledDiffs.get(w);
int currentInt = (int) current;
g2d.drawOval(priorInt, currentInt, 4, 4);
}
}
// Restore the transform for conventional rendering
g2d.setTransform(at);
// ... Rest of the code omitted for brevity
}
// ... Previous code omitted for brevity
}</code>DataPanel.java
<code class="java">//... Previous code omitted for brevity
@Override
protected void paintComponent(Graphics g) {
//... Previous code omitted for brevity
int blueTop = ins.bottom+(vPad/2)+titleStrHeight;
int blueHeight = height-bottomPad-blueTop;
int blueWidth = blueHeight;
int blueBottom = blueHeight+blueTop;
//... Previous code omitted for brevity
// Rotate the graphics context for y-axis labels
g2d.rotate(Math.toRadians(-90), 0, 0);
g.drawString(yString, -(height/2)-(yStrWidth/2), yStrHeight);
// Restore the graphics context for normal rendering
g2d.rotate(Math.toRadians(+90), 0, 0);
//... Previous code omitted for brevity
}</code>其他资源
有关图形转换的更多信息，请参阅：
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