The dimensions defined in the code are causing the issue since the same variable name is being used when defining a dimension and the NETCDF variable itself. Here's the code for your reference:
% Load the MAT file
load('gdp_hourly_velocities_f86e_04a9_23f1.mat')
% Extract variables
ld1 = gdp_hourly_velocities.drogue_lost_date;
lt1 = gdp_hourly_velocities.latitude;
rw1 = gdp_hourly_velocities.rowsize;
st1 = gdp_hourly_velocities.DeploymentStatus;
% Create the NetCDF file and variables
% 'record' is the name for number of entries of each variable, i.e. 364
nccreate('ncfile.nc', 'ld1', 'Dimensions', {'record', size(ld1, 1)}, 'Datatype', 'double');
ncwrite('ncfile.nc', 'ld1', ld1);
nccreate('ncfile.nc', 'lt1', 'Dimensions', {'record', size(lt1, 1)}, 'Datatype', 'single');
ncwrite('ncfile.nc', 'lt1', lt1);
nccreate('ncfile.nc', 'rw1', 'Dimensions', {'record', size(rw1, 1)}, 'Datatype', 'int32');
ncwrite('ncfile.nc', 'rw1', rw1);
% For the 'char' variables we need to map the char_dim to accurately
nccreate('ncfile.nc', 'st1', 'Dimensions', {'record', size(st1, 1), 'char_dim', size(st1, 2)}, 'Datatype', 'char');
ncwrite('ncfile.nc', 'st1', st1);
For more information regarding the definition of dimensions for a variable while using "nccreate", refer to this documentation: https://www.mathworks.com/help/matlab/ref/nccreate.html?s_tid=doc_ta#:~:text=Dimensions%20of%20the,the%20current%20length.
