错误使用 graphalgs Input argument should be a sparse array. 出错 graphconncomp (line 98) [s,c] = graphalgs('wcc',debug_level,directed,G); 出错 graphminspantree (line 110) [num_comp,classes] = graphconncomp(G,'directed',false); 出错 minimumspanningtreePrim (line 3) minSpanTree = graphminspantree(adjMatrix);
时间: 2024-04-18 20:26:00 浏览: 67
这个错误是由于在使用 graphconncomp 函数时,输入参数应该是一个稀疏数组。根据错误信息,在 graphconncomp 函数内部调用了 graphalgs 函数,其中的参数 G 应该是一个稀疏数组。请确保你传递给 graphconncomp 函数的参数 G 是一个稀疏数组类型的变量。你可以使用 spconvert() 函数将密集数组转换为稀疏数组,然后再传递给 graphconncomp 函数。
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报错:错误使用 wdencmp (line 98) Invalid argument value. 出错 E_5 (line 74) xd = wdencmp('gbl',c,s,Lo_R,Hi_R,thr,sorh,keepapp);
这个错误通常是因为输入参数`thr`的值不正确导致的。建议检查一下阈值的计算方式是否正确。
如果您使用的是之前的代码,请尝试使用以下代码来手动计算阈值:
```matlab
% 读入cameraman图像
img = imread('cameraman.tif');
% Daubechies小波包三尺度的低通和高通滤波器系数
Lo_D = [0.0352 -0.0854 -0.1350 0.4599 0.8069 0.3327];
Hi_D = [-0.3327 0.8069 -0.4599 -0.1350 0.0854 0.0352];
Lo_R = Hi_D(end:-1:1);
Hi_R = Lo_D(end:-1:1);
% 压缩处理
[c,s] = wavedec2(img,3,Lo_D,Hi_D);
% 手动计算Shannon熵准则所需的阈值
sigma = median(abs(c)) / 0.6745;
thr = sigma * sqrt(2*log(numel(c)));
sorh = 's';
keepapp = 1;
xd = wdencmp('gbl',c,s,Lo_R,Hi_R,thr,sorh,keepapp);
% 显示原始图像和处理结果
figure;
subplot(1,2,1);
imshow(img);
title('原始图像');
subplot(1,2,2);
imshow(xd);
title('处理结果');
```
在这个代码中,我们使用中位数绝对偏差(MAD)来估计噪声的标准差`sigma`,然后手动计算Shannon熵准则所需的阈值`thr`。这个方法比之前的方法更稳健,通常在实践中更可靠。
array.filter((item, index) => array.indexOf(item) === index);
This code snippet filters an array to only include unique values. It accomplishes this by using the `filter()` method on the array and passing a callback function as an argument. The callback function takes two parameters: `item`, which represents the current element being processed, and `index`, which represents the index of the current element.
Inside the callback function, the `indexOf()` method is used to check if the current item is the first occurrence of that element in the array. If it is, then the `indexOf()` method will return the current index of the element, which will match the `index` parameter passed to the callback function. If it is not the first occurrence, then the `indexOf()` method will return the index of the first occurrence of that element, which will not match the `index` parameter.
By comparing the return value of `indexOf()` with the `index` parameter, we can determine if the current item is unique or not. If it is, then the callback function returns `true`, which includes the item in the filtered array. If it is not unique, then the callback function returns `false`, which excludes the item from the filtered array.