Issues using 'readtable' (MATLAB 2024a)

The following code had worked in the past to read Excel files as tables in MATLAB.

elec_list = readtable('/Users/.../preprocessed_data/databases/elec_list.xlsx', 'Sheet','main');

Recently, the same code doesn't work (no paths or filenames have been changed) and yields the following error:

Error using ones
Size inputs must be scalar.

Error in any (line 65)
sz = [sz,ones(1,DIM-length(sz))];

Error in readtable (line 501)
if any(cellfun(@(arg) isa(arg,"matlab.io.ImportOptions"),varargin),'all')
    

A few things I tried:

1. Running the code in MATLAB 2023b and MATLAB 2024a
2. Testing which version I am using:

which readtable 
/Applications/MATLAB_R2024a.app/toolbox/matlab/iofun/readtable.m

3. Using the MATLAB interactive environment I try loading the data but it says it contains uninterpretable data.

I checked the Excel file and it is not corrupted. I tried created the file from de novo and then copying the data making sure nothing was weird. This didn't work.

Thank you for your help.

Answer 1

[Steven Lord]

Let's check that you haven't accidentally defined a length.m function that does not behave the same way as the one included in MATLAB. What does this display?

which -all length

built-in (/MATLAB/toolbox/matlab/elmat/length)
built-in (/MATLAB/toolbox/matlab/elmat/@double/length)                             % double method
built-in (/MATLAB/toolbox/matlab/elmat/@int16/length)                              % int16 method
built-in (/MATLAB/toolbox/matlab/elmat/@int32/length)                              % int32 method
built-in (/MATLAB/toolbox/matlab/elmat/@int64/length)                              % int64 method
built-in (/MATLAB/toolbox/matlab/elmat/@int8/length)                               % int8 method
built-in (/MATLAB/toolbox/matlab/elmat/@logical/length)                            % logical method
built-in (/MATLAB/toolbox/matlab/elmat/@single/length)                             % single method
built-in (/MATLAB/toolbox/matlab/elmat/@uint16/length)                             % uint16 method
built-in (/MATLAB/toolbox/matlab/elmat/@uint32/length)                             % uint32 method
built-in (/MATLAB/toolbox/matlab/elmat/@uint64/length)                             % uint64 method
built-in (/MATLAB/toolbox/matlab/elmat/@uint8/length)                              % uint8 method
length is a built-in method                                                        % string method
/MATLAB/toolbox/matlab/lang/+matlab/+mixin/@Scalar/Scalar.m                        % dictionary method
/MATLAB/toolbox/matlab/datatypes/categorical/@categorical/length.m                 % categorical method
/MATLAB/toolbox/matlab/graphfun/@digraph/digraph.m                                 % digraph method
/MATLAB/toolbox/matlab/graphfun/@graph/graph.m                                     % graph method
/MATLAB/toolbox/matlab/datatypes/tabular/@tabular/tabular.m                        % tabular method
/MATLAB/toolbox/matlab/datatypes/datetime/@datetime/datetime.m                     % datetime method
/MATLAB/toolbox/matlab/datatypes/duration/@duration/duration.m                     % duration method
length is a built-in method                                                        % matlab.internal.capability.Capability method
length is a built-in method                                                        % connector.internal.LoggerLevel method
length is a built-in method                                                        % matlab.lang.OnOffSwitchState method
/MATLAB/toolbox/matlab/indexing/+matlab/+mixin/+indexing/@RedefinesParen/length.m  % matlab.mixin.indexing.RedefinesParen method
length is a built-in method                                                        % containers.Map method
length is a built-in method                                                        % matlab.internal.reference.property.RefEntityType method
length is a built-in method                                                        % matlab.internal.reference.api.EntityPrecision method
length is a built-in method                                                        % matlab.internal.reference.property.DeprecationStatus method
length is a built-in method                                                        % matlab.internal.reference.property.FunctionType method
length is a built-in method                                                        % matlab.internal.reference.property.SyntaxType method
length is a built-in method                                                        % matlab.internal.reference.api.EntityCaseSensitivity method
length is a built-in method                                                        % simulink.FindSystemTask.Status method
length is a built-in method                                                        % mf.zero.meta.Language method
length is a built-in method                                                        % dig.config.CommandType method
length is a built-in method                                                        % dig.config.HorizontalAlignment method
length is a built-in method                                                        % dig.config.ResourceState method
length is a built-in method                                                        % dig.config.ResourceType method
length is a built-in method                                                        % dig.model.DisplayState method
length is a built-in method                                                        % dig.model.EventDataType method
length is a built-in method                                                        % dig.model.FunctionType method
length is a built-in method                                                        % dig.model.ValidInBdType method
length is a built-in method                                                        % dig.model.ViewMode method
length is a built-in method                                                        % matlab.unittest.internal.fixtures.FolderScope method
length is a built-in method                                                        % matlab.automation.Verbosity method
length is a Java method                                                            % java.io.File method
length is a Java method                                                            % java.lang.String method
length is a Java method                                                            % java.lang.CharSequence method
length is a built-in method                                                        % matlab.internal.timer.CallBackTypeEnum method
length is a built-in method                                                        % matlab.internal.timer.BusyModeEnum method
length is a built-in method                                                        % matlab.internal.timer.ExecutionModeEnum method
/MATLAB/toolbox/matlab/bigdata/@tall/length.m                                      % tall method
built-in                                                                           % gpuArray method
/MATLAB/toolbox/matlab/serial/@serial/length.m                                     % serial method
/MATLAB/toolbox/matlab/timeseries/@tscollection/length.m                           % tscollection method
/MATLAB/toolbox/icomm/opc/opc/@opcroot/length.m                                    % opcroot method
/MATLAB/toolbox/imaq/imaq/@videoinput/length.m                                     % videoinput method
/MATLAB/toolbox/instrument/instrument/@udp/length.m                                % udp method
/MATLAB/toolbox/instrument/instrument/@icgroup/length.m                            % icgroup method
/MATLAB/toolbox/instrument/instrument/@icdevice/length.m                           % icdevice method
/MATLAB/toolbox/instrument/instrument/@tcpip/length.m                              % tcpip method
/MATLAB/toolbox/instrument/instrument/@Bluetooth/length.m                          % Bluetooth method
/MATLAB/toolbox/instrument/instrument/@gpib/length.m                               % gpib method
/MATLAB/toolbox/instrument/instrument/@visa/length.m                               % visa method
/MATLAB/toolbox/instrument/instrument/@i2c/length.m                                % i2c method
/MATLAB/toolbox/parallel/array/distributed/@codistributed/length.m                 % codistributed method
/MATLAB/toolbox/parallel/array/distributed/@distributed/length.m                   % distributed method
/MATLAB/toolbox/parallel/gpu/gpu/@gpuArray/length.m                                % gpuArray method
/MATLAB/toolbox/parallel/lang/@Composite/length.m                                  % Composite method
/MATLAB/toolbox/robust/rctobsolete/robust/@icsignal/length.m                       % icsignal method
/MATLAB/toolbox/shared/statslib/@dataset/length.m                                  % dataset method

[Camilo]

Thank you for your help, @Steven Lord. This is very helpful

Comparing our outputs, I have a few extra ones coming from toolboxes (MATLAB native and extra ones).

I tried the logical step:

restoredefaultpath

After doing this, my readtable function works. This makes suspect that the eeglab "length.m" functions is the one causing the issues. How should I deal with this issue? Renaming the function from the toolbox (which seems a bit problematic) or what else?

>> which -all length #before doing restoredefaultpath
built-in (/Applications/MATLAB_R2024a.app/toolbox/matlab/elmat/length)
built-in (/Applications/MATLAB_R2024a.app/toolbox/matlab/elmat/@double/length)                                                                                                                  % double method
built-in (/Applications/MATLAB_R2024a.app/toolbox/matlab/elmat/@int16/length)                                                                                                                   % int16 method
built-in (/Applications/MATLAB_R2024a.app/toolbox/matlab/elmat/@int32/length)                                                                                                                   % int32 method
built-in (/Applications/MATLAB_R2024a.app/toolbox/matlab/elmat/@int64/length)                                                                                                                   % int64 method
built-in (/Applications/MATLAB_R2024a.app/toolbox/matlab/elmat/@int8/length)                                                                                                                    % int8 method
built-in (/Applications/MATLAB_R2024a.app/toolbox/matlab/elmat/@logical/length)                                                                                                                 % logical method
built-in (/Applications/MATLAB_R2024a.app/toolbox/matlab/elmat/@single/length)                                                                                                                  % single method
built-in (/Applications/MATLAB_R2024a.app/toolbox/matlab/elmat/@uint16/length)                                                                                                                  % uint16 method
built-in (/Applications/MATLAB_R2024a.app/toolbox/matlab/elmat/@uint32/length)                                                                                                                  % uint32 method
built-in (/Applications/MATLAB_R2024a.app/toolbox/matlab/elmat/@uint64/length)                                                                                                                  % uint64 method
built-in (/Applications/MATLAB_R2024a.app/toolbox/matlab/elmat/@uint8/length)                                                                                                                   % uint8 method
length is a built-in method                                                                                                                                                                     % string method
length is a built-in method                                                                                                                                                                     % matlab.lang.internal.FunctionInvocationType method
length is a built-in method                                                                                                                                                                     % matlab.internal.capability.Capability method
length is a Java method                                                                                                                                                                         % java.io.File method
length is a built-in method                                                                                                                                                                     % connector.internal.LoggerLevel method
length is a Java method                                                                                                                                                                         % java.lang.String method
length is a Java method                                                                                                                                                                         % java.lang.CharSequence method
length is a built-in method                                                                                                                                                                     % containers.Map method
length is a built-in method                                                                                                                                                                     % matlab.desktop.editor.RtcEditorState method
length is a built-in method                                                                                                                                                                     % matlab.lang.OnOffSwitchState method
/Users/camilocastelblanco/Dartmouth College Dropbox/Camilo Castelblanco Riveros/ieeg-mimetic/analysis_scripts/main/matlab_scripts/matlab_toolboxes/eeglab2023.0/functions/@mmo/length.m         % mmo method
/Users/camilocastelblanco/Dartmouth College Dropbox/Camilo Castelblanco Riveros/ieeg-mimetic/analysis_scripts/main/matlab_scripts/matlab_toolboxes/eeglab2023.0/functions/@memmapdata/length.m  % memmapdata method
/Users/camilocastelblanco/Dartmouth College Dropbox/Camilo Castelblanco Riveros/ieeg-mimetic/analysis_scripts/main/matlab_scripts/matlab_toolboxes/eeglab2023.0/functions/@eegobj/length.m      % eegobj method
/Applications/MATLAB_R2024a.app/toolbox/matlab/bigdata/@tall/length.m                                                                                                                           % tall method
/Applications/MATLAB_R2024a.app/toolbox/matlab/serial/@serial/length.m                                                                                                                          % serial method
built-in                                                                                                                                                                                        % gpuArray method
/Applications/MATLAB_R2024a.app/toolbox/matlab/datatypes/categorical/@categorical/length.m                                                                                                      % categorical method
/Applications/MATLAB_R2024a.app/toolbox/matlab/timeseries/@tscollection/length.m                                                                                                                % tscollection method
/Applications/MATLAB_R2024a.app/toolbox/parallel/lang/@Composite/length.m                                                                                                                       % Composite method
/Applications/MATLAB_R2024a.app/toolbox/parallel/array/distributed/@codistributed/length.m                                                                                                      % codistributed method
/Applications/MATLAB_R2024a.app/toolbox/parallel/array/distributed/@distributed/length.m                                                                                                        % distributed method
/Applications/MATLAB_R2024a.app/toolbox/parallel/gpu/gpu/@gpuArray/length.m                                                                                                                     % gpuArray method
/Applications/MATLAB_R2024a.app/toolbox/shared/statslib/@dataset/length.m                                                                                                                       % dataset method