Landmark warping

Step 1: Define template landmarks

  • Add landmark: Left-click outside template

  • Delete landmark: Right-click on a landmark

  • Move landmark: Left-click and drag landmark

  • Finish: L to lock template (Points cannot be added after locking template!)

Step 2: Adjust source templates

  • Move landmarks to homologous locations on each source

  • Select source: left-click on line OR use arrow keys to cycle through sources OR click on relevant row from the table

  • Move landmark: Left-click and drag landmark

Manual warping

Manual (Gaussian-kernel-based) warps are defined using four parameters:

  • y — original 1D data

  • center — warp kernel center, relative to its feasible range (between 0 and 1)

  • amp — warp kernel amplitude, relative to its feasible range (between -1 and 1)

  • head — warp kernel head width, relative to its feasible range (between 0 and 1)

  • tail — warp kernel tail width, relative to its feasible range (between 0 and 1)

The meaning of these four parameters is depicted in the figure below.

(Source code, png, hires.png, pdf)


In order to conduct manual warping, follow the steps below.

See also the manual warping screencast.

Step 1: Position the mouse

  • Move the mouse on the axes to the position at which you wish to initiate the warp. This will set the center parameter.

Step 2: Initiate the warp

  • Press the “W” key to initiate a manual warp.

Step 3: Adjust the warp

  • Drag the mouse left-and-right to adjust the amp parameter.

  • Drag the mouse up-and-down to adjust the head and tail parameters.

Step 4: Finalize the warp

  • Press “Enter” to apply the warp. Alternatively press “ESC” to cancel the warp.

Step 5: Restore to original data

  • If you are unhappy with the warp results, press “R” to restore the original data.

  • This will delete all existing warps for the currently selected curve.

Restoring previous sessions

If something went wrong during warping (e.g. a software crash), or if you would like to revisit previous warping sessions, then:

  1. Launch mwarp1d

  2. Drag a previous session’s output (NPZ) file on to the main window’s Drop Data box.

This will restore the previous session, allowing you to adjust and/or reset the previously saved warps.