为何指定TXT路径后GAMS仍以.put扩展名存储结果？

Hey there! Let's figure out why your specified .txt file isn't being created and GAMS is falling back to the default .put extension. Here are the most likely culprits and fixes:

1. Path Parsing Issues (Most Common) #

Your file path has two red flags that GAMS might struggle with:

• Spaces in the folder name: RS Results has a space, which GAMS doesn't handle correctly unless the entire path is wrapped in double quotes.
• Single backslashes: In GAMS, a single backslash \ is an escape character, so Windows-style paths need either double backslashes \\ or forward slashes / to be parsed correctly.

Your original code:

file mse /D:\RS Results\mse_goal(0.5).txt/; put mse;

GAMS reads this as trying to create a file named D:\RS (truncated at the space) with extra invalid parameters, so it gives up and uses the default .put file.

Fix: #

Rewrite the file declaration with proper quoting and path formatting:

// Option 1: Double backslashes with quotes
file mse /"D:\\RS Results\\mse_goal(0.5).txt"/;
put mse;

// Option 2: Forward slashes (GAMS handles this cross-platform)
file mse /"D:/RS Results/mse_goal(0.5).txt"/;
put mse;

2. Missing or Misplaced File Closure #

If you're writing multiple lines to the file, make sure you explicitly close it with putclose mse; after your last write operation. This ensures GAMS finalizes the file with your specified name instead of leaving it in a temporary state that might default to .put.

3. Permissions or Folder Access Issues #

If the D:\RS Results folder doesn't allow write access for the user running GAMS, GAMS can't create your .txt file there. It'll instead create a .put file in your working directory (where it has permissions) as a fallback.

Fix: #

Check that you have write permissions for the target folder, or run GAMS as an administrator if needed.

内容的提问来源于stack exchange，提问作者Sam