Recent News
SNAP Version 2.6.8 Released
February 10, 2019
AptPlot 6.8.0 Updated
February 19, 2018
PyPost 1.3.3 Released
February 19, 2018
AptPlot Resources

AptPlot - A Free Pure-Java 2D Plotting Tool

AptPlot is a free WYSIWYG 2D plotting tool designed for creating production quality plots of numerical data and performing data analysis. AptPlot contains extensive scripting and GUI support for the manipulation and analysis of data sets. AptPlot is intended to be a pure-Java drop-in replacement for the the Motif X-Window based Grace plotting package maintained by the Grace Team and coordinated by Evgeny Stambulchik.

Download AptPlot

PyPost is now included with the AptPlot distribution for SUG members.

PyPost - A Python Postprocessor for Analysis of Code Results and Experimental Data

PyPost consists of a Python library and stand-alone Java application designed to provide advanced post-processing capability for engineering analysis codes and experimental data results. PyPost is licensed to SNAP User's Group (SUG) members.

AptPlot Overview

Read an overview of the AptPlot application and its features. A brief history of AptPlot is also presented.


AptPlot is released under the GPL. Read the license and the licenses of included technologies.

Change Log

ACS Plug-in 2.3.3 - released November 20, 2018:

  • The PARCS plot file support was modified to resolve an error which prevented global plot variables from being plotted using the shortcut P#_<channel> syntax
  • The plot file read routines for FAST plot files were updated to account for new data channels added to the latest version of the FAST analysis code and to correct several of the existing data channel definitions which had been copied directly from FRAPCON.

ACS Plug-in 2.3.3 - released February 19, 2018:

  • An issue has been resolved that prevented proper SI/British engineering unit conversion in TRACE Axial Plots.

ACS Plug-in 2.3.2 - released February 7, 2018:

  • An issue was resolved that would throw an exception when plotting unrecognized  variables from a RELAP5/RELAP5-3D plot file. Unrecognized variables are treated as unit-less values, plotted with a dependent variable label of “Undefined”.
  • The RELAP5-3D PIB plot file format reading logic has been updated to improve the performance for large files.
  • Several FAST binary plot file and FRAPCON/FAST output file read routine optimizations were added that significantly increase the read speed from these file formats.

ACS Plug-in 2.3.1 - released January 10, 2018:

  • An issue was resolved in the TRACE channel selection dialog which could throw an exception when oppening multiple XTV files. The dialog could fail to open after closing XTV files.
  • TRACE channel selection dialog now includes a button to reload the selected file. This should be used when a TRACE run overwrites a file that is currently open in AptPlot.

AptPlot 6.8.0 / ACS Plug-in 2.3.0 - released December 1, 2017:

  • Updated to Java 8. Starting with this version, Java 8 or newer is required. Bundled 1.8.0_152 JVM's are included for the 64-bit Windows and 64-bit Linux platforms.
  • An issue was resolved which prevented AptPlot from opening demultiplexed EXTDATA files.
  • Updated to support the FAST analysis code. This includes updates to the interface and additional batch commands. The following batch commands can be used to read data values from a fast plot file (more information on the available FAST command set can be found in APTPLOT’s help set section “Analysis Code Support Plug-in > Scripting Functionality > Command Interpreter Additions > FAST Commands”):
    • FAST [fileindex] "filename"
    • FASTREAD [fileindex] ["channel"] [unitsType]