Find X values at a specified Y value over a region of interest in a data plot.

Purpose
This app can be used to find X values at "level crossings" (a specific Y value), over a region of interest within a data plot.
Multiple data plots in the layer is also supported.

Installation
Download the file "Level Crossing.opx", then drag-and-drop the file onto the Origin workspace.

Operation

1. With a graph window active, click the "Level Crossing" icon in the Apps panel. A dialog will open. The dialog box provides several options.
2. Click the Help button in the top right corner of the dialog box to open the help file for an explanation of dialog settings and an example.
3. If you have multiple data plots in the layer, there is an option to output the level crossing points for all data plots.

v1.63 9/9/2026 Fix bugs
v1.62 1/14/2026 Support cross X level
v1.61 1/7/2025 Update source file name to avoid conflict
v1.6 1/2/2025 Fix merging cell issue
v1.5 11/3/2020 Support for nonlinear axes
v1.4 9/10/2019 Support for deadtime points, need version higher than Origin 2019b (not included)
v1.3 2/5/2018 Support for Origin regular version
v1.2 1/17/2018 Support output for all curves in the layer
v1.1 9/23/2016 Add warning for non-monotonic data