用java 画几个函数曲线

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public class Test {
    public static void main(String[] args) {
        TriFunc tri = new TriFunc();
       
        // 生成一块25×100的画布
        Canvas canvas = new Canvas(25, 120);

        // 画sin曲线，周期为2
        tri.drawSin(canvas, 2.0);
        canvas.printCanvas();
       
        System.out.println();
        canvas.reset();
        // 画cos曲线，周期为2
        tri.drawCos(canvas, 2.0);
        canvas.printCanvas();
    }
}

class TriFunc {

    /**
     * 画sin曲线
     * @param canvas 画布
     * @param period 曲线周期
     */
    public void drawSin(Canvas canvas, double period) {       
        char[][] chars = canvas.getCanvas();
        // x 轴的比率
        double xRatio = (2 * period * Math.PI) / (canvas.getWidth() - 1);
        // y 轴的放大倍率
        int yMulti = (canvas.getHeight() - 1) / 2;
        for(int i = 0; i < canvas.getWidth(); i++) {
            // 将数组索引映射为横坐标值
            double k = (i - canvas.getWidth() / 2) * xRatio;
            // 将sin值映射为数组索引
            int h = yMulti - (int)Math.round(Math.sin(k) * yMulti);
            chars[h][i] = Canvas.FILL_CHAR;
        }
    }
   
    /**
     * 画cos曲线
     * @param canvas 画布
     * @param period 曲线周期
     */
    public void drawCos(Canvas canvas, double period) {
        char[][] chars = canvas.getCanvas();
        double xRatio = (2 * period * Math.PI) / (canvas.getWidth() - 1);
        int yMulti = (canvas.getHeight() - 1) / 2;
        for(int i = 0; i < canvas.getWidth(); i++) {
            double k = (i - canvas.getWidth() / 2) * xRatio;
            int h = yMulti - (int)Math.round(Math.cos(k) * yMulti);
            chars[h][i] = Canvas.FILL_CHAR;
        }
    }
}


class Canvas {
   
    private int height;
    private int width;
    private char[][] canvas;  
   
    // 填充字符
    public static char FILL_CHAR = '+';
    // 空白字符
    public static char BLANK_CHAR = ' ';
   
    /**
     * 构建一块画布
     * @param height
     * @param width
     */
    public Canvas(int height, int width) {
        // 由于需要画坐标轴，所以得采用奇数
        this.height = height % 2 == 0 ? height + 1 : height;
        this.width = width % 2 == 0 ? width + 1 : width;              
        init();
    }
   
    /**
     * 初始化画布
     */
    private void init() {
        this.canvas = new char[height][width];
        for(int i = 0; i < height; i++) {
            for(int j = 0; j < width; j++) {
                canvas[i][j] = BLANK_CHAR;
            }
        }
        addAxis();
    }
   
    /**
     * 添加坐标轴
     */
    private void addAxis() {
        // 添加横坐标
        int y = height / 2;
        for(int x = 0; x < width; x++) {
            canvas[y][x] = '-';
        }
        // 添加纵坐标
        int xx = width / 2;
        for(int yy = 0; yy < height; yy++) {
            canvas[yy][xx] = '|';
        }
        // 添加原点
        canvas[y][xx] = '+';
    }
   
    /**
     * 输出画布
     */
    public void printCanvas() {
        for(int i = 0; i < height; i++) {
            for(int j = 0; j < width; j++) {
                System.out.print(canvas[i][j]);
            }
            System.out.println();
        }
    }
   
    /**
     * 清空画布
     */
    public void reset() {
        init();
    }
   
    public int getHeight() {
        return height;
    }
    public int getWidth() {
        return width;
    }

    public char[][] getCanvas() {
        return canvas;
    }   
}

评论

3 楼 zengjinliang 2009-02-10  

写的不错，收藏了，呵呵

2 楼 whaosoft 2009-02-06  

呵呵 挺好玩的

1 楼 radovi 2009-02-06  

我也刚在看图形那块 呵呵