Mercurial > forge
changeset 12104:33042ff651ed octave-forge
units: use compact and one-line option to ease parse of Units (bug #38270)
* units.m: by making use of the --compact and --one-line options, GNU units
only outputs the conversion factor so it won't be necessary to parse it from
the output making a call to str2double enough. Remove call to eval(). Give
more meaningful errors for input checking, and identify possible attempts to
non-linear conversions. Change style to follow Octave coding conventions.
Add more tests.
| author | carandraug |
|---|---|
| date | Sun, 20 Oct 2013 18:51:38 +0000 |
| parents | 359f1fe75e3b |
| children | 8af1224f9744 |
| files | main/miscellaneous/inst/units.m |
| diffstat | 1 files changed, 37 insertions(+), 15 deletions(-) [+] |
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--- a/main/miscellaneous/inst/units.m Fri Oct 18 12:54:14 2013 +0000 +++ b/main/miscellaneous/inst/units.m Sun Oct 20 18:51:38 2013 +0000 @@ -1,4 +1,5 @@ ## Copyright (C) 2005 Carl Osterwisch <osterwischc@asme.org> +## Copyright (C) 2013 Carnë Draug <carandraug@octave.org> ## ## This program is free software; you can redistribute it and/or modify it under ## the terms of the GNU General Public License as published by the Free Software @@ -14,7 +15,7 @@ ## this program; if not, see <http://www.gnu.org/licenses/>. ## -*- texinfo -*- -## @deftypefn {Function File} {} units (@var{fromUnit}, @var{toUnit}) +## @deftypefn {Function File} {} units (@var{fromUnit}, @var{toUnit}) ## @deftypefnx {Function File} {} units (@var{fromUnit}, @var{toUnit}, @var{x}) ## Return the conversion factor from @var{fromUnit} to @var{toUnit} measurements. ## @@ -35,21 +36,40 @@ ## @end example ## @end deftypefn -function y = units(fromUnit, toUnit, x) - if 2 > nargin || 3 < nargin || !ischar(fromUnit) || !ischar(toUnit) - print_usage; - endif +function y = units (fromUnit, toUnit, x = 1) + + if (nargin < 2 || nargin > 3) + print_usage (); + elseif (! ischar (fromUnit)) + error ("units: FromUNIT must be a string"); + elseif (! ischar (toUnit)) + error ("units: ToUNIT must be a string"); + elseif (! isnumeric (x)) + error ("units: X must be numeric"); + endif - [status, rawoutput] = system(sprintf('units "%s" "%s"', fromUnit, toUnit), 1); - (0 == status) || error([rawoutput, - 'Verify that GNU units is installed in the current path.']); - - i = index(rawoutput, "*"); - j = index(rawoutput, "\n") - 1; - i && (i < j) || error('parsing units output "%s"', rawoutput); + cmd = sprintf ('units --compact --one-line "%s" "%s"', fromUnit, toUnit); + [status, rawoutput] = system (cmd); + if (status) + error ("units: %s\nVerify that GNU units is installed in the current path.", + rawoutput); + endif - exist("x", "var") || (x = 1); - eval(['y = x', rawoutput(i:j), ';']) + ## FIXME missing support for non-linear conversions. See for example: + ## units --compact --one-line tempC tempF + c_factor = str2double (rawoutput); + if (any (isnan (c_factor(:)))) + if (index (rawoutput, "=")) + ## If there's an equal on the output, it was probably a formula + ## for a non-linear conversion such as "tempC(x) = x K + stdtemp" + error ("units: no support for non-linear conversion of '%s' to '%s'", + fromUnit, toUnit); + else + error ("units: unable to parse output %s from GNU units.", rawoutput); + endif + endif + + y = x * c_factor; endfunction %!demo @@ -58,4 +78,6 @@ %! c.unit = 'kg'; %! c.value = units(a.unit, c.unit, a.value) + units(b.unit, c.unit, b.value) -%!assert( units("in", "mm"), 25.4 ) +%!assert (units ("in", "mm"), 25.4) +%!assert (units ("in", "mm", [5 7; 8 9]), 25.4 * [5 7; 8 9]) +%!error <non-linear conversion> units ("tempC", "tempF")