Undefined variable "testsets" or class "testsets"

I want to change the dataset from 'cuhk03.mat' to 'cuhk03_detected_lomo.mat',when i run the same program,there has an erro shows

     % >> prepare_imdb
Undefined variable "testsets" or class "testsets"
wrong in  prepare_imdb (line 14)
test = testsets{testsets_num,1};

But there has no error when i use the 'cuhk03.mat'(the‘cuhk03_detected_lomo.mat' is a dataset which has been processed with LOMO characteristics).The complete code is as follows：

    % clear;
%you can download this file. It contains data.
load('..\cuhk03-prepare-eval/cuhk03_detected_lomo.mat');
imdb.meta.sets = ['train','test'];
count = 0;
label = 0;
%choose a split
testsets_num = 6; %cuhk03 has 20 different splits, and this value can be 1 ~ 20.
p = sprintf('./split%d_256_1/',testsets_num);
if(~exist(p,'dir'))
    mkdir(p);
end
test = testsets{testsets_num,1};
cc = [];
for k=1:numel(detected)  %camera
    im = detected{k,1};
    for i = 1:size(im,1)  %identity
        A = find(test(:,1) == k);
        B = find(test(:,2) == i);
        C = intersect(A,B);
        if(~isempty(C))
            continue;
        end
        label = label+1;
        temp = 0;
        for j=1:10  %image
            file = im{i,j};
            url = sprintf('F:/2016_person_re-ID-master/2016_person_re-ID-master/cuhk03-prepare-eval/split%d_256/%d_%d_%d_1.jpg',testsets_num,k,i,j);
            if(~isempty(file))
                disp(url);
                imwrite(imresize(file,[256,256]),url);
                temp = temp + 1;
                count = count + 1;
                %disp(count);
                imdb.images.data(count) = cellstr(url);
                imdb.images.label(count) = label;
            end
        end
        cc = [cc;temp];
    end
end
imdb.images.set = ones(1,count);
imdb.images.set(:,randi(count,[round(0.1*count),1])) = 2;
list = find(imdb.images.set==2);
for i=1:numel(list)
    if cc(imdb.images.label(list(i)))<9
        imdb.images.set(list(i))=1;
    end
end
save(sprintf('cuhk_data_256_split%d_1.mat',testsets_num),'imdb','-v7.3');

Answer 1

[Walter Roberson]

You are doing load() with no output arguments. That causes variables to be created in the current workspace. Your code then relies upon variables with those particular names existing. But what happens if what you load() has different variable names, or structures the information differently, or perhaps does not contain the information at all?

[mengqiu ren]

I generally understand what you mean, can you tell me how to do it?

[Walter Roberson]

Show us

 whos -file cuhk03.mat
  whos -file cuhk03_detected_lomo.mat

I suspect that the processed file does not contain the information you need.

[mengqiu ren]

Oh!I made a mistake，it is not the 'cuhk03.mat',it is'cuhk_data_256_split6.mat' generated in 'prepare_imd.m'. https://github.com/layumi/2016_person_re-ID/blob/master/cuhk03-prepare-eval/prepare_imdb.m And it is so big that i can not attach it with the paper clip icon. and the cuhk03_detected_lomo.mat is on http://www.cbsr.ia.ac.cn/users/scliao/projects/lomo_xqda/#references

[Walter Roberson]

Sorry, I do not offer assistance for biometrics.

[mengqiu ren]

Thank you. I'll try something else

Answer 2

[madhan ravi]

You didn’t define testsets

[mengqiu ren]

But why it go wrong when i just change the dataset? Can you tell me how to do it

[Walter Roberson]

Your datasets do not contain the expected variable names.

[madhan ravi]

I’ll illustrate with an example ,

I have a .mat file named as Madhan.mat.

So I load the file in script say

load Madhan.mat

It contains variables a,b and c.

But instead I say

d.^2 in the next line.

What does MATLAB show me now in command window?

It says Undefined function or variable d.

Likewise it’s the same in your case so the so called testsets is not there in file .

But if you insist using testsets in the script you can rename the variable name as such .

datas = Madhan.mat

testsets = datas.a

Now what happens ? The variable name a is changed to testsets likewise you should do it for your case.

[mengqiu ren]

I see what you mean,Thank you!

[madhan ravi]

Anytime

[mengqiu ren]

It do not have the information which i need in the new .mat file . And the information in the two file have different format，so it can not result by the method of mandatory definition.I decide to change a method.

[madhan ravi]

yeah right atleast you found the answer for whats the causing the problem , your question here was "Undefined variable "testsets" or class "testsets""