Why do I receive the error "Insufficient number of outputs from right hand side of equal sign to satisfy assignment. Error in A01_pr_rain_UK (line 3) fname=fns1.name "?

close all;clear all;clc;

%

fns1=dir('Aus pr_Amon_ACCESS-CM2_ssp126_r1i1p1f1_gn_20150616-20990916_v20191108.nc'); %%%%%Australia

fns2=dir('Ger pr_Amon_AWI-CM-1-1-MR_ssp126_r1i1p1f1_gn_20150616-20990916_v20190529.nc'); %%%%%Germany

fns3=dir('pr_Amon_CanESM5-CanOE_ssp126_r1i1p2f1_gn_20150616-21000916_v20190429.nc'); %%%%%Canada

fns4=dir('pr_Amon_UKESM1-0-LL_ssp126_r1i1p1f2_gn_20150616-21000916_v20190503.nc'); %%%%%UK

fns5=dir('Ind pr_Amon_IITM-ESM_ssp126_r1i1p1f1_gn_20150616-20990916_v20201112.nc'); %%%%%India

fname1=fns1.name;

fname2=fns2.name;

fname3=fns3.name;

fname4=fns4.name;

fname5=fns5.name;

lon_aus=double(ncread(fname1,'lon'));

lat_aus=double(ncread(fname1,'lat'));

pr_aus=double(ncread(fname1,'pr'));

tm_aus=double(ncread(fname1,'time'));

pr_aus1=pr_aus*86400;

t_aus=datetime('1850-01-01')+tm_aus;

[yyyy_aus mm_aus dd_aus hh_aus mn_aus ss_aus]=datevec(t_aus);

lon_ger=double(ncread(fname2,'lon'));

lat_ger=double(ncread(fname2,'lat'));

pr_ger=double(ncread(fname2,'pr'));

tm_ger=double(ncread(fname2,'time'));

pr_ger1=pr_ger*86400;

t_ger=datetime('1850-01-01')+tm_ger;

[yyyy_ger mm_ger dd_ger hh_ger mn_ger ss_ger]=datevec(t_ger);

lon_can=double(ncread(fname3,'lon'));

lat_can=double(ncread(fname3,'lat'));

pr_can=double(ncread(fname3,'pr'));

tm_can=double(ncread(fname3,'time'));

pr_can1=pr_can*86400;

t_can=datetime('1850-01-01')+tm_can;

[yyyy_can mm_can dd_can hh_can mn_can ss_can]=datevec(t_can);

lon_uk=double(ncread(fname4,'lon'));

lat_uk=double(ncread(fname4,'lat'));

pr_uk=double(ncread(fname4,'pr'));

tm_uk=double(ncread(fname4,'time'));

pr_uk1=pr_uk*86400;

t_uk=datetime('1850-01-01')+tm_uk;

[yyyy_uk mm_uk dd_uk hh_uk mn_uk ss_uk]=datevec(t_uk);

lon_ind=double(ncread(fname5,'lon'));

lat_ind=double(ncread(fname5,'lat'));

pr_ind=double(ncread(fname5,'pr'));

tm_ind=double(ncread(fname5,'time'));

pr_ind1=pr_ind*86400;

t_ind=datetime('1850-01-01')+tm_ind;

[yyyy_ind mm_ind dd_ind hh_ind mn_ind ss_ind]=datevec(t_ind);

%%%%%%%%%%%%Australia model!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

pr_aus2=(pr_aus1((find(lon_aus>=70 & lon_aus<=75)),(find(lat_aus>=15 & lat_aus<=20)),(find(mm_aus==6))));

pr_aus_avg=squeeze(nanmean(nanmean(pr_aus2)));

%%%%%%%%%%%%IITM model!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%Germany model!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

pr_ger2=(pr_ger1((find(lon_ger>=70 & lon_ger<=75)),(find(lat_ger>=15 & lat_ger<=20)),(find(mm_ger==6))));

pr_ger_avg=squeeze(nanmean(nanmean(pr_ger2)));

%%%%%%%%%%%%IITM model!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%Canadar model!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

pr_can2=(pr_can1((find(lon_can>=70 & lon_can<=75)),(find(lat_can>=15 & lat_can<=20)),(find(mm_can==6))));

pr_can_avg=squeeze(nanmean(nanmean(pr_can2)));

%%%%%%%%%%%%IITM model!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%Canadar model!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

pr_uk2=(pr_uk1((find(lon_uk>=70 & lon_uk<=75)),(find(lat_uk>=15 & lat_uk<=20)),(find(mm_uk==6))));

pr_uk_avg=squeeze(nanmean(nanmean(pr_uk2)));

%%%%%%%%%%%%IITM model!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%IITM model!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

pr_ind2=(pr_ind1((find(lon_ind>=70 & lon_ind<=75)),(find(lat_ind>=15 & lat_ind<=20)),(find(mm_ind==6))));

pr_ind_avg=squeeze(nanmean(nanmean(pr_ind2)));

%%%%%%%%%%%%IITM model!%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

figure(1)

plot(pr_aus_avg,'-k')

hold on;

plot(pr_ger_avg,'-r')

hold on;

plot(pr_can_avg,'-b')

hold on;

plot(pr_uk_avg,'-g')

hold on;

plot(pr_ind_avg,'-m')

legend ('Australia', 'Germany' ,'Canada', 'UK', 'India')

stop;

months=[ 'Jun'; 'Jul'; 'Aug'; 'Sep']

subplot(231)

pcolor(lon_aus,lat_aus,squeeze(pr_aus1(:,:,2))')

shading interp

caxis([0 30]);

axis([65 100 0 40])

hold on

load coast

plot(long,lat,'w','linewidth',2)

subplot(232)

pcolor(lon_ger,lat_ger,squeeze(pr_ger1(:,:,2))')

shading interp

caxis([0 30]);

axis([65 100 0 40])

hold on

load coast

plot(long,lat,'w','linewidth',2)

subplot(233)

pcolor(lon_can,lat_can,squeeze(pr_can1(:,:,2))')

shading interp

caxis([0 30]);

axis([65 100 0 40])

hold on

load coast

plot(long,lat,'w','linewidth',2)

subplot(234)

pcolor(lon_uk,lat_uk,squeeze(pr_uk1(:,:,2))')

shading interp

caxis([0 30]);

axis([65 100 0 40])

hold on

load coast

plot(long,lat,'w','linewidth',2)

subplot(235)

pcolor(lon_ind,lat_ind,squeeze(pr_ind1(:,:,2))')

shading interp

caxis([0 30]);

axis([65 100 0 40])

hold on

load coast

plot(long,lat,'w','linewidth',2)

set(gcf,'color','w');

Answer 1

[Luca Ferro]

'dir' returns an empty structure since for whatever reason, most likely a path issue, it cannot find the said files.

The empty structure has a property 'name', which is empty as well and so the assignment cannot be performed. You can check this by debugging with a breakpoint on line:

fname1=fns1.name;

To solve the issue i would double check the path and the availability of the files.

Another suggestion i give you is to use arrays of structs instead of several variables with numbers in their names (you can do this since 'dir' returns structures with the same fields, so:

fns(1)=dir('Aus pr_Amon_ACCESS-CM2_ssp126_r1i1p1f1_gn_20150616-20990916_v20191108.nc'); %%%%%Australia

fns(2)=dir('Ger pr_Amon_AWI-CM-1-1-MR_ssp126_r1i1p1f1_gn_20150616-20990916_v20190529.nc'); %%%%%Germany

fns(3)=dir('pr_Amon_CanESM5-CanOE_ssp126_r1i1p2f1_gn_20150616-21000916_v20190429.nc'); %%%%%Canada

fns(4)=dir('pr_Amon_UKESM1-0-LL_ssp126_r1i1p1f2_gn_20150616-21000916_v20190503.nc'); %%%%%UK

fns(5)=dir('Ind pr_Amon_IITM-ESM_ssp126_r1i1p1f1_gn_20150616-20990916_v20201112.nc'); %%%%%India

Or if those are the only .nc files present in your folder, a one line would do the trick:

fns=dir('pathToYourFolder\*.nc')

Doing so instead of rewriting the same lines for each variable you can just easily loop them reducing the code size to 1/5 of the original.