Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / io-1.0.19 / append_save.m

diff --git a/octave_packages/io-1.0.19/append_save.m b/octave_packages/io-1.0.19/append_save.m
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+## Copyright (C) 2003 Tomer Altman <taltman@lbl.gov>
+##
+## 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
+## Foundation; either version 3 of the License, or (at your option) any later
+## version.
+##
+## This program 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
+## this program; if not, see <http://www.gnu.org/licenses/>.
+
+## append_save M-file function
+##
+## Objective: be able to add variables to existing save files. Works for
+## all the types of save files that "save" supports.
+## 
+## Input: 
+## 1) A string which specifies the existing save file.
+## 2) The options you need to pass to the 'save' function to save to the
+## file type that you want.
+## 3) A 1x2 cell, with the first element being a string representation
+## of the variable/symbol that you're trying to add, followed by the
+## actual variable/symbol itself.
+## 4) Any number of additional 1x2 cells, following the same format as
+## the 3rd argument specified immediately before this one.
+##
+## Output:
+## Currently, none. But there might be some debugging / error-code
+## messages in the future.
+##
+## Example:
+## octave> B = ones(2,2);
+## octave> append_save( "test.txt", "-binary", {"B", B } )
+
+
+function [ return_value ] = append_save ( filename,
+                                         option,
+                                         var_val_cell,
+                                         varargin )
+
+  ## Input checking:
+
+  if ( nargin < 3 )
+    error("append_save: needs three arguments.");
+  elseif ( !ischar(filename) )
+    error("append_save: filename must be a string.");
+  elseif ( !ischar(option) )
+    error("append_save: option must be a string." );
+  elseif ( !iscell(var_val_cell) )
+    error("append_save: variable-value pairs must be cells.")
+  elseif ( nargin > 3 )
+    for i=1:(nargin-3)
+      current_cell = varargin(i);
+      if ( !iscell(current_cell) )
+       error("append_save: variable-value pairs must be cells.");
+      elseif ( ( columns( current_cell ) != 2 ) 
+               || ( rows( current_cell ) != 1 ) )
+       error("append_save: variable-value pairs must be 1x2 cells.")
+      elseif ( !ischar(current_cell{1} ) )
+       error("append_save: variable in pair must be a string." )
+      endif
+    endfor
+  endif
+
+  ## First step: load into the environment what is already stuffed in
+  ## the target file. Then, add their name to the list for "save".
+
+  env1 = who;
+  
+  eval([ "load -force ", \
+       option, " ",    \
+       filename ] );
+
+  env2 = who;
+  
+  num_orig_vars = rows(env1);
+
+                               # Not really 'current' env...
+  num_current_vars = rows(env2);
+
+  num_new_vars = num_current_vars - num_orig_vars;
+
+  var_str = "";
+
+  ## This double 'for loop' weeds out only the loaded vars for
+  ## inclusion.
+
+  if ( num_new_vars )
+
+    for i=1:num_current_vars
+
+      current_var = env2{i,1};
+
+      old_bool = 0;
+
+      for j=1:num_orig_vars
+
+       if ( strcmp( env1{j,1}, env2{i,1} ) 
+            ||
+            strcmp( env2{i,1}, "env1" ) )
+
+         old_bool = 1;
+
+       endif
+
+      endfor
+
+      if ( old_bool == 0 )
+
+       var_name = env2{i,1};
+
+       var_str = [ var_str, " ", var_name, " " ];
+
+      endif
+
+    endfor
+
+  endif
+
+  
+  ## Second step: load into the environment the variable pairs. Then,
+  ## add the name to the string for "save".
+
+  var_name = var_val_cell{1};
+
+  var_val = var_val_cell{2};
+
+  temp = var_val;
+
+  eval([ var_name, "=temp;" ]);
+
+  var_str = [ var_str, " ", var_name, " " ];
+
+  ## Third step: do the same as step two, but loop through the possible
+  ## variable arguments.
+
+  for i=1:(nargin-3)
+
+    current_cell = varargin(i);
+
+    var_name = current_cell{1};
+    
+    var_val = current_cell{2};
+    
+    temp = var_val;
+    
+    eval([ var_name, "=temp;" ]);
+    
+    var_str = [ var_str, " ", var_name, " " ];
+
+    var_str
+
+  endfor
+
+  ## Finally, save all of the variables into the target file:
+
+  eval( [ "save ", \
+          option, " ",  \
+          filename, " ", var_str; ] );
+
+endfunction