table: summary: omit NaNs from mean(), include NaN counts

CHANGES.txt

@@ -4,16 +4,17 @@ Tablicious Changelog
 Unreleased (in progress)
 -----------------------
 
-* Add `end` override methods to `string`, `datetime`, etc. so `x(end)` indexing works correctly.
+* Add `end` override methods to string, datetime, etc. so `x(end)` indexing works correctly.
+* table: summary: omit NaNs from mean(), include NaN counts
 
 0.4.1 (2024-02-07)
 ------------------
 
 ### Bug Fixes
 
-* `string`:
-  * `string`: Fix missing trailing newline in string display in `string.disp`.
-  * `string`: Add `+` operator overload that does string concatenation.
+* string:
+  * string: Fix missing trailing newline in string display in `string.disp`.
+  * string: Add `+` operator overload that does string concatenation.
 
 Version 0.4.0 (2024-02-07)
 --------------------------

inst/+tblish/+internal/nanmean.m

@@ -0,0 +1,48 @@
+## Copyright (C) 2024 Andrew Janke <floss@apjanke.net>
+##
+## This file is part of Tablicious.
+##
+## Octave 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 Foundation, either version 3 of the License, or
+## (at your option) any later version.
+##
+## Octave is distributed in the hope that it will be useful, but
+## WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with Octave; see the file COPYING.  If not, see
+## <https://www.gnu.org/licenses/>.
+
+function out = nanmean (x, dim)
+  # mean, omitting NaNs
+  #
+  # This function exists so that we can do this on Octaves prior to 7.x, which did
+  # not support the 'omitnan'option.
+  #
+  # This is a minimal implementation that supports only the mean calculations that table
+  # needs.
+  if (ndims (x) > 2)
+    error ('tblish.internal.nanmean: only 2-D inputs are supported');
+  endif
+
+  if (isvector (x) && nargin == 1)
+    x2 = x (~isnan(x));
+    out = mean (x2);
+  else
+    if (nargin < 2 || isempty (dim)); dim = 1; endif
+    if (dim == 1)
+      out = NaN (1, size (x, 2));
+      for i = 1:size (x, 2)
+        out(i) = tblish.internal.nanmean (x(:,i));
+      endfor
+    elseif (dim == 2)
+      outInv = tblish.internal.nanmean (x', 1);
+      out = outInv';
+    else
+      error ('tblish.internal.nanmean: invalid dim argument: %d', dim)
+    endif
+  endif
+endfunction

inst/@table/table.m

@@ -3267,10 +3267,12 @@ function summary_impl (this, fmt)
 endfunction
 
 function out = summary_for_var_numeric (x)
-  x_min = min (x);
-  x_mean = mean (x);
-  x_max = max (x);
-  x_prcts = prctile (x, [25 50 75]);
+  xvec = x(:);
+  x_min = min (xvec);
+  x_mean = tblish.internal.nanmean (xvec);
+  x_max = max (xvec);
+  x_prcts = prctile (xvec, [25 50 75]);
+  n_nans = sum (isnan (xvec));
   out = {
     'Min.'      num2str(x_min)
     '1st Qu.'   num2str(x_prcts(1))
@@ -3279,6 +3281,9 @@ function summary_impl (this, fmt)
     '3rd Qu.'   num2str(x_prcts(3))
     'Max.'      num2str(x_max)
   };
+  if (n_nans > 0)
+    out = [out; {'N. NaN', num2str(n_nans)}];
+  endif
 endfunction
 
 function out = summary_for_var_categorical (x)