maint: Clean up m-files to follow Octave coding conventions. Try to trim long lines to < 80 chars. Use '##' for single line comments. Use '(...)' around tests for if/elseif/switch/while. Abut cell indexing operator '{' next to variable. Abut array indexing operator '(' next to variable. Use space between negation operator '!' and following expression. Use two newlines between endfunction and start of %!test or %!demo code. Remove unnecessary parens grouping between short-circuit operators. Remove stray extra spaces (typos) between variables and assignment operators. Remove stray extra spaces from ends of lines.

--- a/scripts/general/logspace.m
+++ b/scripts/general/logspace.m
@@ -90,7 +90,7 @@
 %! assert (size (x3) == [1, 10] && abs (x3(1) - 10) < eps && abs (x3(10) - 0.01) < eps);
 %! assert (size (x4) == [1, 10] && abs (x4(1) - 10) < eps && abs (x4(10) - pi) < sqrt (eps));
 
-%% Test input validation
+## Test input validation
 %!error logspace ()
 %!error logspace (1, 2, 3, 4)
 %!error logspace ([1, 2; 3, 4], 5, 6)