matlab - Save .mat file, use -v7.3 switch? -

i'm running m-file, creating 2 variables, clus , watts_map. want save both variables file ends in ".mat". both variables dimensioned (1152,241,319), 1152 360 deg longitude in 0.3125 deg increments, 241 latitude 30s-30n in 0.25 deg increments, on 319 time steps. code works way until end, error:

[warning: variable 'clus' cannot saved mat-file version older 7.3. save variable, use -v7.3 switch. skipping...]  [warning: variable 'watts_map' cannot saved mat-file version older 7.3. save variable, use -v7.3 switch. skipping...]  

i using matlab version r2014a, think current version. also, have run same exact code on smaller spatial domain (but on 2920 timesteps) without error.

%  clear variables, initialize counter, indexed timestep clc; clear all;  rain = nan(1152,241,319); clus = nan(1152,241,319); areas_final = nan(500,319);  wattage_final = nan(500,319); cluster_size = zeros(319,1); watts_map = zeros(1152,241,319);  year = 2000%:2008;     nyear = sprintf('%04d',year);      %  call on files each year     filename = (['pr_3hr_gfdl-hiram-c360_amip_r1i1p1_' num2str(nyear) '010100-' num2str(nyear) '123123_subset_tropics.nc']);     disp(filename)     disp(year)      rain_rate = ncread(filename,'pr');      %  call on each timestep     = 960:4:2236; % approx may 1st-sep 30th          %  set extract subset region, mask land areas, each         %  timestep          disp(i)         rain = rain_rate(:,:,i);          % eliminate bad/no data points         index_rain = (rain >= (5.4e-05)) & (rain < 1e-2); % 0.2mm/hr min rain rate          % cluster each morning , afternoon matrix         clus(:,:,i) = cluster_it(index_rain);          % calculate cluster areas         areas = cluster_areas_tropics(clus(:,:,i));         areas_final(1:length(areas),i) = areas;          % calculate cluster wattages         wattage = cluster_wattage(clus(:,:,i),rain);          cluster_size(i,1) = max(max(clus(:,:,i)));          % create dummy matricies populate , use create wattage         % maps         d = zeros(1152,241);         e = squeeze(clus(:,:,i));         index = 1:cluster_size(i);             d(e == index) = wattage(index);         end          watts_map(:,:,i) = d;          % clear dummy matricies         clear d e      end      % save output .mat file     file_out = sprintf(num2str(nyear), year);     matfile = [file_out '_tropics_watts_maps_inc_land_low_rain_threshold.mat'];     save(matfile, 'clus', 'watts_map');      % clear unneeded variables save memory , prevent overwriting     clear index_rain rain areas wattage clus file_out filename areas_final rain_rate watts_map cluster_size year matfile  end 

even in current version, default format not v7.3. must specify it:

save(matfile, '-v7.3', 'var1', 'var2'); 

you can set default in "general preferences":

note v7.3 compress data of r2008a:

compression of -v7.3 mat-files

can store data items on 2 gigabytes in size in mat-file using -v7.3 option save function. option introduced in matlab r2006b. matlab r2008a, save compresses these mat-files.

i've seen file size blow v7.3 files, history , perhaps it's better now.