function write_vector_to_file_for_DSP(x, outputFilename)
%write_vector_to_file_for_DSP(x, outputFilename)
%this script takes a vector input of values that are assumed to have 
%magnitude less than 1 and outputs these values to a file that is formatted
%for TI DSP assembly code (for cutting/pasting into assembly).
%The function will scale the values to 16-bit 2's complement integers by 
%multiplying by 2^15 before writing to the output file.

if nargin < 2
    fprintf('Syntax: write_vector_to_file_for_DSP(x, outputFilename)\n');
    fprintf('\tMust specify input vector x to be written to a \n');
    fprintf('\tfile specified by the string name in outputFilename');    
    return;
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Error-checking stuff

% check amplitude
maxAmplitude = max(abs(x));
if maxAmplitude > 1
    fprintf('Maximum amplitude of input must not exceed 1!');
    return;
end

% check dimensions (verify that input is a vector
[m, n] = size(x);
if (m > 1) && (n > 1)
    fprintf('Input must be a vector (either row or a column)');
    return;
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

x = round(x * (2^15-1));  % scale fractions to 16-bit integers

vals_per_line = 8;
full_lines = floor(length(x) / vals_per_line);
label  = inputname(1);
label2 = '';
startIndex = 1;
f = fopen(outputFilename, 'w');

for k = 1 : full_lines
    
    endIndex = startIndex + vals_per_line - 1;
    if length(label) ~= 0
        label2 = sprintf('%s%d', label, (k-1) * vals_per_line);
        %pad with up to 5 spaces (for up to 5-digit numbers)
        label2 = [label2, ' ' * ones(1, length(label) + 5 - length(label2))];
    end
    fprintf(f, '%s\t .word \t', label2);
    fprintf(f, '%d, ', x(startIndex:endIndex-1));
    fprintf(f, '%d \r\n', x(endIndex));
    startIndex = startIndex + vals_per_line;
end

left_over = length(x) - startIndex + 1;
if (left_over > 0)
    
    if length(label) ~= 0
        label2 = sprintf('%s%d', label, full_lines * vals_per_line);
        %pad with up to 5 spaces (for up to 5-digit numbers)
        label2 = [label2, ' ' * ones(1, length(label) + 5 - length(label2))];
    end
    fprintf(f, '%s\t .word \t', label2);
    fprintf(f, '%d, ', x(startIndex:end-1));
    fprintf(f, '%d \r\n', x(end));
end
fclose(f);