A MATLAB function to convert from component value to formatted string with engineering suffix.

engFormat.m

function string = engFormat(value, type)
%ENGFORMAT a function to take a passive electronic component value and
% return a string with the properly formatted suffix.

aVal = abs(value);
nn = 0;

if strcmp(type,'R')
    type = char(937);
end

if strcmp(type,'C')
    type = 'F';
end

if strcmp(type,'L')
    type = 'H';
end

if aVal>=1
    while aVal*10^(-nn) > 10
        nn = nn+1;
    end
    
    positive = {' ', 'k', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'};
    ind = min(floor(nn/3), length(positive)-1);
    
    nDigits = nn - 3*floor(nn/3) + 1;
    
    string = sprintf('%s%.4f %s%s',repmat(' ',1,3-nDigits), value*10^(-3*ind), positive{ind+1}, type);
else
    while aVal*10^(-nn) < 1
        nn = nn - 1;
    end
    
    negative = {' ', 'm', char(956), 'n', 'p', 'f', 'a', 'z', 'y'};
    
    ind = min(ceil(-nn/3), length(negative)-1);
    nDigits = 3*ceil(-nn/3) + nn + 1;
    
    string = sprintf('%s%.4f %s%s', repmat(' ',1,3-nDigits), value*10^(3*ind), negative{ind+1}, type);
end

end