FIX #2137 - merge columns with datetime objects, thanks to @JonathanV…

…Hoecke

private/mergetable.m

@@ -46,15 +46,15 @@
 if nargin==2
   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   % merge by comparing the complete rows
-  
+
   assert(isequal(t1.Properties.VariableNames, t2.Properties.VariableNames));
-  
+
   [m1, n1] = size(t1);
   [m2, n2] = size(t2);
-  
+
   % the unique function fails on tables if the values are mixed, e.g. empty, scalars, and strings
   % the following compares every row by computing a hash for it.
-  
+
   h1 = cell(m1,1);
   for i=1:m1
     h1{i} = ft_hash(t1(i,:));
@@ -63,10 +63,10 @@
   for i=1:m2
     h2{i} = ft_hash(t2(i,:));
   end
-  
+
   [c, i1, i2] = union(h1, h2, 'stable');
   t3 = cat(1, t1(i1,:), t2(i2,:));
-  
+
   %     match = true(m2,1);
   %
   %     for j2=1:m2
@@ -76,20 +76,20 @@
   %     end
   %
   %     t3 = cat(1, t1, t2(~match,:));
-  
+
 elseif nargin==3
   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   % merge using the specific key
-  
+
   c1 = t1.Properties.VariableNames;
   c2 = t2.Properties.VariableNames;
-  
+
   assert(any(contains(c1, key)));
   assert(any(contains(c2, key)));
-  
+
   [m1, n1] = size(t1);
   [m2, n2] = size(t2);
-  
+
   % don't try to merge if one of them is empty
   if m1==0 && m2>0
     t3 = t2;
@@ -98,33 +98,37 @@
     t3 = t2;
     return
   end
-  
+
   for i=1:n1
     if ischar(t1{1,i})
       t1.(c1{i}) = cellstr(t1{:,i});
     elseif isnumeric(t1{1,i})
       t1.(c1{i}) = num2cell(t1{:,i});
+    elseif isdatetime(t1{1,i})
+      t1.(c1{i}) = datetime2cell(t1{:,i});
     end
   end
-  
+
   for i=1:n2
     if ischar(t2{1,i})
       t2.(c2{i}) = cellstr(t2{:,i});
     elseif isnumeric(t2{1,i})
       t2.(c2{i}) = num2cell(t2{:,i});
+    elseif isdatetime(t2{1,i})
+      t2.(c2{i}) = datetime2cell(t2{:,i});
     end
   end
-  
+
   t3 = table();
-  
+
   % deal with the columns that are present in both inputs
   col = intersect(c1, c2);
-  
+
   for i=1:numel(col)
     % copy the existing column from t1 into t3
     t3.(col{i}) = t1.(col{i});
   end
-  
+
   for j=1:m2
     row = findkey(t1.(key), t2.(key){j});
     if ~any(row)
@@ -142,47 +146,47 @@
       t3(row, col{i}) = t2(j, col{i});
     end
   end
-  
+
   n3 = size(t3,1);
-  
+
   % deal with the columns that are only present in the 1st input
   col = setdiff(c1, c2);
-  
+
   for i=1:numel(col)
     % add an empty column to t3
     t3.(col{i}) = cell(n3, 1);
   end
-  
+
   for j=1:m1
     row = findkey(t3.(key), t1.(key){j});
     for i=1:numel(col)
       t3(row, col{i}) = t1(j, col{i});
     end
   end
-  
+
   % deal with the columns that are only present in the 2nd input
   col = setdiff(c2, c1);
-  
+
   for i=1:numel(col)
     % add an empty column to t3
     t3.(col{i}) = cell(n3, 1);
   end
-  
+
   for j=1:m2
     row = findkey(t3.(key), t2.(key){j});
     for i=1:numel(col)
       t3(row, col{i}) = t2(j, col{i});
     end
   end
-  
+
   % reorder the columns to match the input
   c3 = unique(cat(2, c1, c2), 'stable');
   [c3, ia, ib] = intersect(c3, t3.Properties.VariableNames, 'stable');
   t3 = t3(:,ib);
-  
+
 else
   ft_error('incorrect number of input arguments');
-  
+
 end % if nargin
 
 
@@ -192,3 +196,12 @@
 function ret = findkey(list, elem)
 match = @(x) isequal(x, elem);
 ret = cellfun(match, list);
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% SUBFUNCTION
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+function c = datetime2cell(d)
+c = cell(size(d));
+for i=1:numel(d)
+  c{i} = d(i);
+end