Reference to non-existent field 'data'.
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P='C:\Users\Lenovo\OneDrive\Desktop\NB_veh_files';
>> S=dir(fullfile(P,'*.csv'));
>> for K=1:numel(S)
F=fullfile(P,S(k).name);
S(k).data=readmatrix(F);
end
>> figure
>> hold on
>> for k=1:1388
plot (S(k).data(:,1), S(k).data(:,4),'black','LineWidth',0.1)
end
Reference to non-existent field 'data'.
Can anyone help me how to update the code so that I don't get the error message
6 个评论
Stephen23
2023-3-10
"Can anyone help me how to update the code so that I don't get the error message"
Most likely S is empty so the loop does not iterate and the field DATA is not created.
Please show us the output of this command:
size(S)
Laxmi Bhatta
2023-3-10
As I wrote, variable S is empty (because no files were found by DIR at the given path), so the loop never iterates.
Please show the output of this command:
dir(P)
Laxmi Bhatta
2023-3-10
Laxmi Bhatta
2023-3-10
"'C:\Users\Lenovo\OneDrive\Desktop\NB_veh_files' not found."
Lenovo is an odd user name. Well, in any case, clearly you need to provide a path that actually exists and that MATLAB can access (i.e. permitted by the access rights of the account that you are using).
"'/This PC/Desktop/NB_veh_files' not found."
Of course not, "This PC" does not exist on any path, it is simply an attempt by MS to confuse its users.
"P='/Desktop/NB_veh_files'"
might work, if the MATLAB current directory is in the user folder and the files are saved in that subfolder (actually saved, not just links of whatever kind). But you do not say, what is the current directory that you have selected for MATLAB to use.
Do not simply copy from the MS File Explorer address bar, because it will give you a whole lot of nonsense (ask MS if you want to know why). Everything that you see listed under "This PC" and probably "OneDrive" and most things under your user folder do not really exist as folders in your file system, they are just MS registry magic, things that look like folders but are really just made of smoke and mirrors. Sadly MS wants to "abstract" us ways from referring to actual drive locations (because hey, everything is on the cloud, right?)
Go to your C/D/whatever drive. Navigate to the folder you want. Copy that path. Use it.
You could even use MATLAB to do the navigation.
回答（1 个）
Use small k, in place of K , Matlab is case sensitive
P='C:\Users\Lenovo\OneDrive\Desktop\NB_veh_files';
S=dir(fullfile(P,filesep,'*.csv'));
% check with this too
for k=1:numel(S) % use small k
F=fullfile(P,S(k).name);
S(k).data=readmatrix(F);
end
figure
hold on
for k=1:1388
plot (S(k).data(:,1), S(k).data(:,4),'black','LineWidth',0.1)
end
6 个评论
VBBV
2023-3-10
It seems you are using K as the for loop index, but when reading the filenames, you change to smallcase k
Laxmi Bhatta
2023-3-10
P='C:\Users\Lenovo\OneDrive\Desktop\NB_veh_files\';
% add a backslash
A backslash to the path seems missing, to navigate to exact location where your files are present
"Add a backslash in the path"
No, this is not required, because FULLFILE does that automatically. The OPs code does not require any trailing path separator character. Lets try it right now:
P = 'C:\Users\Lenovo\OneDrive\Desktop\NB_veh_files';
fullfile(P,'*.csv')
(the forwardslash is only because this forum runs on Linux, on Windows it would be a backslash).
VBBV
2023-3-10
@Laxmi Bhatta, As @Stephen23 suggested, please also check whether there are any files in that folder location. Also, try using filesep in the below line,
S=dir(fullfile(P,filesep,'*.csv'));
"Also, try using filesep in the below line"
Is not required, for the reason already explained here:
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2023-3-10
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