Operands to the || and && operators must be convertible to logical scalar values.

I am trying to run a series of data thorugh a if loop, to sum the amount of numbers between -0.13 and -0.16 found in each.

When i run this code, i get the error: Operands to the || and && operators must be convertible to logical scalar values.

Can anybody help?

files = dir('*.csv'); %dir lists the files in a folder. In the specified folder, recognise all the .csv files
num_files = length(files); %specify how many files have been found and call it num_files
particledata = cell(length(files), 1); %create a cell array the same length as the number of files in one column
%for all the files found in the specified folder, read the tables of data and fill the empty cell array 'results' with the data in each .csv file
for a = 1:num_files
  particledata{a} = readtable(files(a).name);
end 

ymax = -0.13;
ymin = -0.16;
for b = 1:length(particledata)
    %save all the rows in the 6th column (x-coordinates) of each cell as a new variable x
    x{b} = particledata{b}(:,5);
    %use the function table2array to turn the format of the data from a table to an array
    x_array{b} = table2array(x{b});
    %for all the rows in the array, if the x coordinate goes beyond the outlet
    %of the rice pile, display 'grain left rice pile'
    if x_array{b}>ymin & x_array{b}<ymax
        disp('grain left rice pile');
    end
    %sum the total number of grains leaving the rice pile in each cell, and save into a new variable 'grains'
    grains{b}=sum(x_array{b}>ymin) && (x_array{b}<ymax)
    fprintf('A total of %d grains left the rice pile\n',grains{b});
end 

totalruntime = num_files;
time = 1:totalruntime;
%convert the cell file to a double file to allow plotting of data
grains = cell2mat(grains);

%mass efflux vs. time
%plot 'grains left rice pile' vs. time step as a bar graph
%0.01 sets the width of each bar
figure(1)
bar(time,grains, 0.01, 'EdgeColor', 'r')
title('mass efflux')
xlabel('Time (S)')
ylabel('Mass Efflux (No. of Particles)')

Answer 1

[Walter Roberson]

    grains{b}=sum(x_array{b}>ymin) && (x_array{b}<ymax)

Your sum() ends too early. sum(condition & condition)

[C.G.]

when i run this, I get the error: Operands to the || and && operators must be convertible to logical scalar values.

[Walter Roberson]

Notice that the general form of the correction uses & not &&

[C.G.]

What do you mean? I have used bith & and && in my process to work this out.

If i use '&&' i get this error: Operands to the || and && operators must be convertible to logical scalar values.

If i use '&' i get an error saying brace indexing is not supported.

[Walter Roberson]

    grains{b} = sum(x_array{b}>ymin & x_array{b}<ymax);

[C.G.]

Thanks this has worked now