帮我写一个MATLAB的图片中直线关于斜率的区间进行分类并显示结果的代码

好的，以下是MATLAB代码：

clear all; clc;

% 读取图片并显示
img = imread('image.jpg');
imshow(img);

% 构造灰度图像
grayImg = rgb2gray(img);

% 进行边缘检测
edgeImg = edge(grayImg, 'canny');

% 提取直线并进行分类
[H,theta,rho] = hough(edgeImg);
P = houghpeaks(H, 100);
lines = houghlines(edgeImg,theta,rho,P,'FillGap',10,'MinLength',100);
negLines = [];
posLines = [];
zeroLines = [];
for k = 1:length(lines)
xy = [lines(k).point1; lines(k).point2];
slope = (lines(k).point2(2)-lines(k).point1(2))/(lines(k).point2(1)-lines(k).point1(1));
if slope < 0
negLines = [negLines lines(k)];
elseif slope > 0
posLines = [posLines lines(k)];
else
zeroLines = [zeroLines lines(k)];
end
end

% 显示结果
figure, imshow(img), hold on
for k = 1:length(negLines)
xy = [negLines(k).point1; negLines(k).point2];
plot(xy(:,1),xy(:,2),'LineWidth',2,'Color','green');
end
for k = 1:length(posLines)
xy = [posLines(k).point1; posLines(k).point2];
plot(xy(:,1),xy(:,2),'LineWidth',2,'Color','red');
end
for k = 1:length(zeroLines)
xy = [zeroLines(k).point1; zeroLines(k).point2];
plot(xy(:,1),xy(:,2),'LineWidth',2,'Color','blue');
end
title('直线斜率区间分类结果');