Error using gather when using predict (from ClassificationKNN)

Question

Camilo 2023-7-13

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1995728-error-using-gather-when-using-predict-from-classificationknn

回答： chadows 2024-6-20

采纳的回答： Milan Bansal

在 MATLAB Online 中打开

Thanks in advance.

My code uses ClassfificationKNN to predict classes for my data. The error I get is as follows:

Error using gather
Too many input arguments.
Error in ClassificationKNN/score (line 451)
[CIDX,dist,gindex,W] = gather(CIDX,dist,gindex,W);
Error in ClassificationKNN/predict (line 777)
[posteriors,gindex,CIDX] = score(this,X);

Using the debugger, line 451 raises the issue when trying to Transfer distributed array.

Part of the code I use (portion pertaining to this question):

Note: attached is one sample of training and testing dataset since this is embededded in a for loop.

dist_measure = {'cosine'; 'correlation'; 'spearman';};
distMeas = dist_measure{2};
distWeight = 'inverse';
breakties = 'nearest';
nNeighbors1 = 1;
nNeighbors2 = 9;
training_labels1 = items(ind); %111x1 (1,2,3...28)
training_labels2 = category(ind); %111x1 (1,1,1...2,2,2)
true_label1 = items(indtest); %exemplar (e.g., 1)
true_label2 = category(indtest); %category (e.g., 1)
%from https://lvdmaaten.github.io/drtoolbox/
if DRflag
        %% Performs out-of-sample extension of the new datapoints in points. 
        training_data = out_of_sample(training_data,mapping0); %111x11 (convert 11 objects into 11 feature vectors)
        predicted_data = out_of_sample(predicted_data,mapping0); %1 x 11
    end
mdl1 = fitcknn(training_data,training_labels1,'distance',distMeas,'DistanceWeight',distWeight,...
    'NumNeighbors',nNeighbors1,'BreakTies',breakties); %item decoding
mdl2 = fitcknn(training_data,training_labels2,'distance',distMeas,'DistanceWeight',distWeight,...
    'NumNeighbors',nNeighbors2,'BreakTies',breakties); %category decoding
predicted_label1 = predict(mdl1,predicted_data);
predicted_label2 = predict(mdl2,predicted_data);

2 个评论
显示无隐藏无

Ayush Aniket 2023-8-22

在 MATLAB Online 中打开

Hi Camilo,

I implemented the code you shared with the data provided as shown below:

dist_measure = {'cosine'; 'correlation'; 'spearman';};
distMeas = dist_measure{2};
distWeight = 'inverse';
breakties = 'nearest';
nNeighbors1 = 1;
nNeighbors2 = 9;
training_labels1 = load('training_labels1.txt');
training_labels2 = load('training_labels2.txt');
training_data = load('training_data.txt');
predicted_data = load('predicted_data.txt');
mdl1 = fitcknn(training_data,training_labels1,'distance',distMeas,'DistanceWeight',distWeight,...
    'NumNeighbors',nNeighbors1,'BreakTies',breakties); %item decoding
mdl2 = fitcknn(training_data,training_labels2,'distance',distMeas,'DistanceWeight',distWeight,...
    'NumNeighbors',nNeighbors2,'BreakTies',breakties); %category decoding
predicted_label1 = predict(mdl1,predicted_data);
predicted_label2 = predict(mdl2,predicted_data);

I am not getting any error. I got the following values as answer.

predicted_label1 = 12

predicted_label2 = 1

Let me know in case of any discrepancies.

Camilo 2023-8-22

Thank you for your reply @Ayush Aniket!

The issue has been with my Matlab with the

Error using gather

I am still unsure of why that error shows in my machine but not in others. Regardless, I appreciate you trying.

With gratitude,

Camilo

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Milan Bansal 2023-8-31

2
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1995728-error-using-gather-when-using-predict-from-classificationknn#answer_1298011

在 MATLAB Online 中打开

Hi,

I understand that you are getting an error: "Too many input arguments" while using MATLAB's “gather” function.

It looks like the MATLAB's “gather” function that you are using is being shadowed by some other function or script with the same name. You can check the list of all functions or files with the name “gather” in the MATLAB path by the running the command as shown below.

which gather -all

Rename the shadowed file or remove it from the MATLAB path to resolve the issue.

Refer to the documentation link below to know about MATLAB's “gather” function in different toolboxes.

https://in.mathworks.com/support/search.html?q=gather&page=1 

3 个评论
显示 1更早的评论隐藏 1更早的评论

Camilo 2023-9-2

Thank you this was helpful. It seemed like one of my toolboxes (eeglab) also had a 'gather' function for parallel computing that was interfering with the Matlab process.

Thank you both!

tiecheng 2024-3-20

Thank you very much, your tips are very good, and also solve the RF problem

请先登录，再进行评论。

Answer 2

chadows 2024-6-20

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1995728-error-using-gather-when-using-predict-from-classificationknn#answer_1474786

I have tried to delete those files under this path:

D:\MATLAB\toolbox\eeglab\plugins\ICLabel\matconvnet\matlab\compatibility\parallel\

but when I add

g = which('gather');

disp(g);

code in D:\MATLAB\toolbox\stats\classreg\ClassificationKNN.m line 452, I found "g" is still "D:\MATLAB\toolbox\eeglab\plugins\ICLabel\matconvnet\matlab\compatibility\parallel\gather.m".

Finally, I delete the path: D:\MATLAB\toolbox\eeglab\plugins\ICLabel\matconvnet\matlab\compatibility\parallel\.

Then I succeeded.

>> which('gather')

D:\MATLAB\toolbox\matlab\bigdata\gather.m

I wonder if there is any other better ways.

:)