Corrected Octave bug in nnz with range input

Author: lmendo

compatibility/nnz_comp.m

@@ -0,0 +1,6 @@
+function y = nnz(x)
+% Octave treats ranges specially to save memory: https://www.gnu.org/software/octave/doc/v4.2.0/Ranges.html
+% When applying `nnz` to a range an error occurs. It seems to be solved by linearizing the input (that is,
+% applying index `(:)`). That probably turns the range into an actual column vector
+y = builtin('nnz', x(:));
+end

matl_compile.m

@@ -362,7 +362,7 @@
         'triu' 'tril' 'randsample' 'nchoosek' 'vpa' 'sum' 'mean' 'diff' 'mod' 'repelem' 'dec2bin' 'dec2base' ...
         'hypergeom' 'disp' 'str2func' 'logical' 'circshift' 'pdist2' 'strsplit' 'max' 'min' 'strncmp' 'round'...
         'datestr' 'regexp' 'regexprep' 'imshow' 'mat2str' 'blkdiag' 'strcat' 'str2num' 'str2double' 'cconv' ...
-        'gcd' 'lcm' 'fftn' 'mode'};
+        'gcd' 'lcm' 'fftn' 'mode' 'nnz'};
     verNumTh = [4 0 0]; % first version in which a modified function is not needed:
     if (verNum(1)<verNumTh(1)) || ((verNum(1)==verNumTh(1)) && (verNum(2)<verNumTh(2))) || ((verNum(1)==verNumTh(1)) && (verNum(2)==verNumTh(2)) && (verNum(3)<verNumTh(3)))
         fnames = [fnames {'colon'}];

spec/MATL_spec.aux

@@ -221,5 +221,5 @@
     {1}{127.09738pt}\LT@entry 
     {1}{23.69952pt}\LT@entry 
     {1}{125.09738pt}}
-\@writefile{lot}{\contentsline {table}{\numberline {7}{\ignorespaces Output of predefined literal functions\relax }}{70}{table.caption.8}}
-\newlabel{tab: preLit}{{7}{70}{Output of predefined literal functions\relax \relax }{table.caption.8}{}}
+\@writefile{lot}{\contentsline {table}{\numberline {7}{\ignorespaces Output of predefined literal functions\relax }}{71}{table.caption.8}}
+\newlabel{tab: preLit}{{7}{71}{Output of predefined literal functions\relax \relax }{table.caption.8}{}}

spec/MATL_spec.pdf

@@ -1399,6 +1399,8 @@ \subsection{MATL functions}
 \item
 \matlab+char+ implicitly rounds down in MATLAB, and rounds to closest in Octave. This difference has been addressed by enforcing MATLAB's behaviour.
 Octave's \matlab+mode+ doesn't handle char input. This has been fixed.
+\item
+Octave treats ranges specially to save memory\footnote{\url{https://www.gnu.org/software/octave/doc/v4.2.0/Ranges.html}}. When applying function \matlab+nnz+ to a range an error occurs. This has been fixed.
 \end{itemize}
 
 
@@ -1520,6 +1522,9 @@ \section{Acknowledgments}
 and for finding a bug in the parser, which incorrectly identified \matl{]} or \matl{\}} within strings as closing symbols for array literals.
 % https://chat.stackexchange.com/transcript/message/42555761#42555761
 \item
+\user{@Steadybox} for finding a bug in Octave's \matlab+nnz+ function when applied to a range.
+% Comments in https://codegolf.stackexchange.com/a/155943/36398
+\item
 \user{@Suever} for his help in finding several differences between Octave and MATLAB,
 % regarding the $0$ character, as well as the \matlab+max+ and \matlab+min+ functions;
 % concatenation of chars and logical doesn't work in Matlab