Fix #1248: add renamevars and removevars functions (#1266)

CHANGELOG.md

@@ -25,6 +25,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - `end` magic keyword can be overloaded for classes (applied to `table` class).
 - [#1250](http://github.com/nelson-lang/nelson/issues/1250) `head`, `tail` functions for table and array.
+- [#1248](http://github.com/nelson-lang/nelson/issues/1248) `removevars`, `renamevars` functions for table.
 
 ### Changed
 

modules/table/functions/@table/subsasgn.m

@@ -56,11 +56,19 @@
         if ~isequal(size(before.RowNames), size(value.RowNames))
           error(_('Value assignment must be same size as existing value.'));
         end
-        if isstring(value.VariableNames)
-          value.VariableNames = cellstr(value.VariableNames);
-        end
-        if isstring(value.RowNames)
-          value.RowNames = cellstr(value.RowNames);
+        ce = {};
+        if isstring(value.VariableNames) || iscellstr(value.VariableNames)
+          if iscellstr(value.VariableNames)
+            ce = value.VariableNames;
+          else 
+            ce = cellstr(value.VariableNames);
+          end
+          R = renamevars(T, before.VariableNames, ce);
+          return
+        else 
+          if isstring(value.RowNames)
+            value.RowNames = cellstr(value.RowNames);
+          end
         end
         st.Properties = value;
         R = class(st, 'table'); 
@@ -205,7 +213,7 @@
       end
     else
       % Delete specific columns
-      if ~isequal(idxRow, 1:width(T)) || isempty(idxCol)
+      if ~isequal(idxRow, 1:height(T)) || isempty(idxCol)
         error(_('At least one subscript must be '':'' when you delete rows or variables by assigning [].'));
       end
       for j = idxCol

modules/table/functions/@table/subsref.m

@@ -136,6 +136,9 @@
     % Keep as is
   elseif ischar(rowIdx) || iscellstr(rowIdx) || isstring(rowIdx)
     % Handle row names
+    if ischar(rowIdx)
+      rowIdx = {rowIdx};
+    end
     rowIdx = find(ismember(st.Properties.RowNames, rowIdx));
     if isempty(rowIdx)
       error(_('Row name not found.'));
@@ -147,6 +150,8 @@
   % Handle column indexing
   if ischar(colIdx) && strcmp(colIdx, ':')
     colIdx = 1:width(T);
+  elseif ischar(colIdx) && isrow(colIdx)
+    colIdx = find(ismember(st.Properties.VariableNames, {colIdx}));
   elseif islogical(colIdx)
     colIdx = find(colIdx);
   elseif isnumeric(colIdx)
@@ -156,6 +161,7 @@
   else
     error(_('Invalid column indexing.'));
   end
+
   selectedVarNames = st.Properties.VariableNames(colIdx);
   tableData = cell(1, length(selectedVarNames));
   for i = 1:length(selectedVarNames)

modules/table/functions/removevars.m

@@ -0,0 +1,23 @@
+%=============================================================================
+% Copyright (c) 2016-present Allan CORNET (Nelson)
+%=============================================================================
+% This file is part of the Nelson.
+%=============================================================================
+% LICENCE_BLOCK_BEGIN
+% SPDX-License-Identifier: LGPL-3.0-or-later
+% LICENCE_BLOCK_END
+%=============================================================================
+function varargout = removevars(varargin)
+  nargoutchk(0, 1);
+  narginchk(1, 2);
+  T = varargin{1};
+  mustBeA(T, 'table', 1);
+  if (nargin < 2)
+    vars = [];
+  else
+    vars = varargin{2};
+  end
+  T(:, vars) = [];
+  varargout{1} = T;
+end
+%=============================================================================

modules/table/functions/renamevars.m

@@ -0,0 +1,88 @@
+%=============================================================================
+% Copyright (c) 2016-present Allan CORNET (Nelson)
+%=============================================================================
+% This file is part of the Nelson.
+%=============================================================================
+% LICENCE_BLOCK_BEGIN
+% SPDX-License-Identifier: LGPL-3.0-or-later
+% LICENCE_BLOCK_END
+%=============================================================================
+function varargout = renamevars(varargin)
+  narginchk(3, 3); % Check that there are exactly 3 input arguments
+  nargoutchk(0, 1); % Check that there is at most 1 output argument
+
+  % Unpack input arguments
+  T = varargin{1};
+  oldNames = varargin{2};
+  newNames = varargin{3};
+
+  % Ensure the types are correct
+  mustBeA(T, 'table', 1); % Check if T is a table
+  mustBeText(oldNames, 2); % Check if oldNames are text
+  mustBeText(newNames, 3); % Check if newNames are text
+
+  % Convert oldNames and newNames to cell arrays of strings
+  oldNames = cellstr(oldNames);
+  newNames = cellstr(newNames);
+
+  % Ensure oldNames and newNames are the same length
+  if (length(oldNames) ~= length(newNames))
+    error(_('oldNames and newNames must have the same length.'));
+  end
+
+  % Check for duplicates in oldNames
+  if (length(unique(oldNames)) ~= length(oldNames))
+    error('Duplicate names in oldNames are not allowed.');
+  end
+
+  % Check for duplicates in newNames
+  if (length(unique(newNames)) ~= length(newNames))
+    error('Duplicate names in newNames are not allowed.');
+  end
+
+  % Convert table to struct
+  st = struct(T);
+
+  % Get current fieldnames from st.data
+  currentFields = fieldnames(st.data);
+
+  % Check if all oldNames exist in the current fieldnames
+  for i = 1:length(oldNames)
+    if ~any(strcmp(oldNames{i}, currentFields))
+      error(sprintf(_('Name "%s" not found in the table.'), oldNames{i}));
+    end
+  end
+
+  % Create new struct for renamed fields
+  newData = struct();
+
+  % Copy and rename fields
+  for i = 1:length(currentFields)
+    currentField = currentFields{i};
+    idx = find(strcmp(currentField, oldNames));
+
+    if ~isempty(idx)
+      % If field should be renamed, use new name
+      newData.(newNames{idx}) = st.data.(currentField);
+    else
+      % If field is not in oldNames, keep original name
+      newData.(currentField) = st.data.(currentField);
+    end
+  end
+
+  % Replace old data struct with new one
+  st.data = newData;
+
+  % Update VariableNames in Properties
+  oldVarNames = st.Properties.VariableNames;
+  newVarNames = oldVarNames;
+  for i = 1:length(oldNames)
+    idx = strcmp(oldNames{i}, oldVarNames);
+    if any(idx)
+      newVarNames{idx} = newNames{i};
+    end
+  end
+  st.Properties.VariableNames = newVarNames;
+
+  varargout{1} = class(st, 'table');
+end

modules/table/help/en_US/xml/removevars.xml

@@ -0,0 +1,82 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<xmldoc>
+  <copyright>SAME AS NELSON SOFTWARE</copyright>
+
+  <language>en_US</language>
+  <keyword>removevars</keyword>
+  <short_description>Delete variables from table.</short_description>
+
+  <syntax>
+    <syntax_item>TB = removevars(TA, varsNames)</syntax_item>
+  </syntax>
+
+  <param_input>
+
+    <param_input_item>
+      <param_name>TA</param_name>
+      <param_description>Input table.</param_description>
+    </param_input_item>
+    <param_input_item>
+      <param_name>varsNames</param_name>
+      <param_description
+      >Variable names in input table to remove: character vector, string array or cell array of character vectors.</param_description>
+    </param_input_item>
+
+  </param_input>
+
+  <param_output>
+    <param_output_item>
+      <param_name>TB</param_name>
+      <param_description>Table object modified.</param_description>
+    </param_output_item>
+  </param_output>
+
+  <description>
+  <p><b>TB = removevars(TA, varsNames)</b> removes the variables specified by <b
+      >varsNames</b> from the table <b
+      >TA</b> and stores the remaining variables in <b>T2</b>.</p>
+  <p
+    >You can specify the variables by name, position, or using logical indices.</p>
+  <p>You can also remove variables from a table using <b
+      >T(:, varsNames) = []</b>.</p>
+  </description>
+  <used_function />
+  <bibliography />
+
+<examples>
+
+  <example_item>
+    <example_item_type>nelson</example_item_type>
+    <example_item_description />
+    <example_item_data
+      ><![CDATA[C = {'John', 28, true; 'Alice', 35, false; 'Bob', 42, true};
+% Convert the cell array to a table
+T1 = cell2table(C)
+T2 = removevars(T1, 'C2')
+]]>
+    </example_item_data>
+  </example_item>
+
+</examples>
+
+  <see_also>
+    <see_also_item>
+      <link linkend="${table}table">table</link>
+    </see_also_item>
+    <see_also_item>
+      <link linkend="${table}renamevars">renamevars</link>
+    </see_also_item>
+
+  </see_also>
+
+  <history>
+    <history_item>
+      <history_version>1.9.0</history_version>
+      <history_description>initial version</history_description>
+    </history_item>
+  </history>
+
+  <authors>
+    <author_item>Allan CORNET</author_item>
+  </authors>
+</xmldoc>

modules/table/help/en_US/xml/renamevars.xml

@@ -0,0 +1,94 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<xmldoc>
+  <copyright>SAME AS NELSON SOFTWARE</copyright>
+
+  <language>en_US</language>
+  <keyword>renamevars</keyword>
+  <short_description>Rename variables in table.</short_description>
+
+  <syntax>
+    <syntax_item>TB = renamevars(TA, varsNames, newNames)</syntax_item>
+  </syntax>
+
+  <param_input>
+
+    <param_input_item>
+      <param_name>TA</param_name>
+      <param_description>Input table.</param_description>
+    </param_input_item>
+    <param_input_item>
+      <param_name>varsNames</param_name>
+      <param_description
+      >Variable names in input table: character vector, string array or cell array of character vectors.</param_description>
+    </param_input_item>
+    <param_input_item>
+      <param_name>newNames</param_name>
+      <param_description
+      >New names for variables: character vector, string array or cell array of character vectors.</param_description>
+    </param_input_item>
+
+  </param_input>
+
+  <param_output>
+    <param_output_item>
+      <param_name>TB</param_name>
+      <param_description
+      >Table object with variable names modified.</param_description>
+    </param_output_item>
+  </param_output>
+
+  <description>
+    <p><b
+      >TB = renamevars(TA, varsNames, newNames)</b> renames the variables in the table <b
+      >TA</b> as specified by <b
+      >varsNames</b> and assigns them the new names provided in <b
+      >newNames</b>.</p>
+    <p
+    >You can also rename all the variables in a table by assigning new names to its <b
+      >VariableNames</b> property using <b
+      >T.Properties.VariableNames = newNames</b>.</p>
+    <p>In this case, <b
+      >newNames</b> must be a string array or a cell array of character vectors.</p>
+  </description>
+  <used_function />
+  <bibliography />
+
+<examples>
+
+  <example_item>
+    <example_item_type>nelson</example_item_type>
+    <example_item_description />
+    <example_item_data
+      ><![CDATA[C = {'John', 28, true; 'Alice', 35, false; 'Bob', 42, true};
+% Convert the cell array to a table
+T1 = cell2table(C);
+T2 = renamevars(T1, {'C1', 'C2'}, {'Name', 'Age'})
+T3 = cell2table(C);
+T3.Properties.VariableNames = {'Name', 'Age', 'Married'};
+T3]]>
+    </example_item_data>
+  </example_item>
+
+</examples>
+
+  <see_also>
+    <see_also_item>
+      <link linkend="${table}table">table</link>
+    </see_also_item>
+    <see_also_item>
+      <link linkend="${table}removevars">removevars</link>
+    </see_also_item>
+
+  </see_also>
+
+  <history>
+    <history_item>
+      <history_version>1.9.0</history_version>
+      <history_description>initial version</history_description>
+    </history_item>
+  </history>
+
+  <authors>
+    <author_item>Allan CORNET</author_item>
+  </authors>
+</xmldoc>

modules/table/tests/test_removars.m

@@ -0,0 +1,27 @@
+%=============================================================================
+% Copyright (c) 2016-present Allan CORNET (Nelson)
+%=============================================================================
+% This file is part of the Nelson.
+%=============================================================================
+% LICENCE_BLOCK_BEGIN
+% SPDX-License-Identifier: LGPL-3.0-or-later
+% LICENCE_BLOCK_END
+%=============================================================================
+LastName = {'Sanchez';'Johnson';'Li';'Diaz';'Brown'};
+Age = [38;43;38;40;49];
+Smoker = logical([1;0;1;0;1]);
+Height = [71;69;64;67;64];
+Weight = [176;163;131;133;119];
+BloodPressure = [124 93; 109 77; 125 83; 117 75; 122 80];
+T = table(LastName, Age, Smoker, Height, Weight, BloodPressure);
+R = removevars(T, 'Age');
+REF = table(LastName, Smoker, Height, Weight, BloodPressure);
+assert_isequal(R, REF);
+R2 = removevars(R, 1);
+REF = table(Smoker, Height, Weight, BloodPressure);
+assert_isequal(R2, REF);
+%=============================================================================
+R = removevars(T,{'Smoker','Weight'});
+REF = table(LastName, Age, Height, BloodPressure);
+assert_isequal(R, REF);
+%=============================================================================