PARFOR loop can not run due to the way variable "M" is used.

Hello,

I'm wondering what I can do to variable "M" to make it PARFOR - friendly while keeping it's function.

Any help is appricated - Thanks in advance.

Please find the code below:

clc

clear all

path = 'SW_OPER_MAGA_HR_1B_20170214T000000_20170214T235959_0505_MDR_MAG_HR.cdf';

info = cdfinfo(path) ;

vars=info.Variables ;

data=cdfread(path,'Variables',{'Latitude'});

timestamp=(cdfread(path,'Variables',{'Timestamp'}));

parfor i=1:length(timestamp);

fprintf('processing %d of %d time step one',i,length(timestamp));

datenum(i) = todatenum(timestamp{i});

[year(i), month(i),day(i) ,hh(i),mm(i),ss(i)]=datevec( todatenum(timestamp{i}));

fprintf(' - Time step one calc done \n');

end

parfor i=1:length(mm);

fprintf('processing %d of %d time step two',i,length(mm));

time(i) = hh(i) + mm(i)/60 +(ss(i)/3600);

fprintf(' - Time step two calc done \n');

end

UT = hh+(mm/60)+(ss/3600);

data1 = cell2mat(data);

lat = data1(:,1);

fprintf('start of find...');

f0 = find(UT>0&UT<24);

fprintf(' - find done\n');

f=f0;

f1 = horzcat(f,f(end)+1:f(end));

fprintf(' - f1 done\n');

fprintf('start of cell2mat data1...');

data1=cell2mat(cdfread(path,'Variables',{'Latitude','Longitude','Radius'}));

fprintf(' - cell2mat data1 done\n');

parfor i=1:length(f1);

fprintf('processing %d of %d variables',i,length(f1));

Alt(i) = (data1(f1(i),3)/1000);

fprintf(' - Variables calc done \n');

end

parfor i=1:length(f1);

fprintf('processing %d of %d ms',i,length(f1));

M(i,1) = data1(f1(i),1);

M(i,2) = data1(f1(i),2);

M(i,3) = Alt(i);

M(i,4) = datenum(f1(i));

fprintf(' - ms calc done \n');

end

Answer 1

[Raymond Norris]

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M(i,1) = data1(f1(i),1);
M(i,2) = data1(f1(i),2);
M(i,3) = Alt(i);
M(i,4) = datenum(f1(i));

to

M(i,:) = [data1(f1(i),1) data1(f1(i),2) Alt(i) datenum(f1(i))];

By the way, there's a MATLAB function, datenum. You might consider using a different variable name.

[Pouya]

Thank you Raymond, it worked like a charm!

Can you explain your point on "datenum" a bit further. I didn't quite get it.

[Raymond Norris]

In the call to

datenum(i) = todatenum(timestamp{i});

you are overwriting the MATLAB function, datenum.