Starting from V4.0.0, STDF processing core in STDF-Viewer is re-written in Rust , its parsing speed is comparable to C and it’s memory safe, the stdf library that I developed is also open-sourced and available in crates.io.

[Improvement & New Features]

• Merge multiple STDF files.
• Side-to-side compare multiple STDF files / merged STDF files.
• Support STDF V4-2007 (STR visualization still needs help)
• Superseded DUTs will be marked in DUT Summary table.
• Add DUT counts in Bin and Wafer statistic table.
• Faster plotting and seamlessly interactivity with pyqtgraph.
• Add some useful tools under Utilities menu.
• Redesigned setting GUI.
• Memory consumption reduced.
• Everything is faster.

[Bug Fix]

• Show real wafer ID in DUT Summary.
• Fix app freezing if there are millions of DTR/GDR.
• Fix error when saving DUT data table in CSV/Excel.
• Yield calculation and plots will exclude superseded DUTs.

[Notes]
Following features that are temporarily dropped in 4.0.0, the main reason is that I still need sometime to familiar with pyqtgraph APIs, they might be added in later releases.

• Boxplot in histogram.
• Gaussian fit in histogram.
• Mean, median line in histogram.
• Hovering tips in histogram and bin chart.

[Improvement & New Features]

• Show ATR, RDR, SDR in File Info.
• Add a table for displaying DTR & GDR.
• Add a button for transposing Dut Data Table.
• Limited support zip compressed STDF file (see Readme for details).
• Support STDF files in which test items shares a same test number.

[Improvement & New Features]

• Support STDF files with UTF-8 (compatible with ASCII) or Windows-1252 (compatible with Latin1) encoded text.
• Reduce memory usage, especially for large STDF files.

[Bug Fix]

• Fix an error caused by hiding all sigma lines in the setting.

[Improvement & New Features]

• MPR test is divided into multiple test items, test names are prefixed with the PMR index.
• PMR, Logic/physical/channel names can be displayed in the statistic table for MPR tests.
• Description of RTN_STAT in the MPR test is available as the floating tips in the raw data table and dut data table.
• Pattern name is also shown in the statistic table for FTR tests.
• Floating tips are available for bin summary plots.

[Bug Fix]

• Fix the black icons/background in the matplotlib toolbar.
• Fix some bins in the histogram that are not responding "enter" key.
• Fix a crash that might happen when opening a new file that contains the same test# but a different dut#.
• Fix a crash that might occur when clicking on "check all" in the report generator.

[Improvement & New Features]

• Add an option in the setting to reorder the test list.
• Add a debug panel in "About" to generate logs for issue reporting.
• Show messages in plots when no data is available.
• Show tips when hovering over DUT info in Dut Data Table.
• More detailed error message if the error occurred while reading.

[Bug Fix]

• Fix a crash when opening STDF files with multiple heads.
• Fix a crash when some of PRRs are missing in some files.
• Fix the comma in "(X, Y)" treated as the delimiter in CSV reports.
• Suppress flashing console when opening/revealing files in Windows OS.

[Improvement & New Features]

• Support MPR visualization.
• Support dynamic limits for PTRs with PAT-enabled (Part Averaging Test).
• Interactive plots are available for Histo, Bin & Wafermap.
• Add Chinese Translation (中文化).
• New report generator UI.
• Add XY coordinates in the DUT summary table.
• Add a stacked wafer map that shows the fail counts of each (X, Y).
• Display the info of wafer map if available (size, orientation, etc.)
• Rotate the wafer map to match the directions in WCR.
• Allow the user to change the default fonts.

[Bug Fix]

• Fix app crashes when Unicode characters are in the path or filename.
• Fix app crashes if INF is stored as RESULT in PTRs.
• Fix the bug that data representation in floating tips in Trend plots is not following the setting.
• Fix a bug caused by NULL TEST_TXT in PTR.

Major version V3.0.5 is released!

[Improvement & New Features]

• General

1. The file process efficiency is drastically improved compared to the previous versions. Here is the benchmark on my test machine (mbp 2018 with 16G RAM), the loading time is comparable to some of the commercial software.

Note: gz and bzip2 compressed file is the same as the uncompressed 530 MB, using the best compression

2. Image generation speed is also improved.
3. DUT summary table can sort by its columns.
4. The excel report of the dut summary highlights failed test values.
5. Add descriptions of DUT's flag when the user hovers over the dut summary table.

[Bug Fix]

1. Fix memory consumption too high.
2. Fix Reveal File not working as expected on Windows.
3. Fix some STDF files not visible in the file dialog on Linux.
4. Fix the figure abnormally large on macOS.
5. Fix the statistic of the wafer map is incorrect.

STDF Viewer V2.0.0 is released.

[Improvement & New Features]

• General

1. add support for multi-head stdf files, redesign UI for head number selection
2. add options to turn on/off low Cpk searching during test item fail-check.

• Trend Chart

1. improve marker responsiveness in the trend chart.
2. selectable points in trend chart (for showing dut data).
3. move the toolbar to the right side

• Report

1. add xlsx report in dut data table.
2. support context menu in test summary table.
3. optimize xlsx report style (BG, etc).
4. add the "open report" button in the completion dialog.
5. add the "reveal file" button when the report is finished.

• Memory

1. Reduce RAM by using python array to store stdf data

[Bug Fix]

1. fix a KeyError when the user terminated the reading process of a 2nd file due to the omitted field is cleared.
2. fix bz2 and gz file is not recognized as a valid stdf file.
3. fix WAFER_ID KeyError if no WRR is available.
4. fix the wafer map is not displayed properly
5. fix the Unicode coding error in windows
6. fix the error that ptr's test name is missing
7. fix figure save in UI looks weird
8. fix figure shows in the UI looks weird
9. fix that points can be selected even when the toolbar is selected.
10. fix site selection tab height issue
11. fix x limit issue when there's only one point
12. fix gz progress bar

The 1st release of STDF Viewer, Hooray!