© 2023 Jasper van Baten, AmsterCHEM

Trace curve mode

To trace points on a curve in your graph, you must make sure you are in Trace curve mode. You can select Trace curve mode from the Edit menu, or from the mode selection in the top left of the window. When clicking on or near a line, the point will automatically snap to the line. The point can be moved around using Ctrl in combination with the arrow keys, while selected.

You can only enter Trace curve mode if your axes have been defined.

You can trace both solid and dashed curves. To start tracing, select a first point on the line. Then select the last point on the line. ScanIt will find the shortest route connecting the points, while traveling over lines.

tracing a curve

Make sure the scan window size is set appropriately. The scan window size (in pixels) should capture the significant features of the image (such as line thickness and distance between parts of dotted or dashes lines). Choosing the window size too small may cause ScanIt to fail to find connections between dotted or dashed lines. Choosing the window size too large may cause ScanIt to not see the line at all, or take steps that are too big. Change the window size to update the route along the line.

ScanIt may not immediately find a route along the desired line, but take a short cut along some other line(s) in your image. To prevent ScanIt from taking a shortcut in a wrong direction, select the line direction in the top of the window (e.g. positive X direction will prevent steps being taken in a negative X direction).

Click more points along the missed parts of the line to correct the trace. Adding a point in a regions of sharp curvature is advised, such as at the top of the curve in this image.

tracing a curve

Click on the accept button will move the found points into a new data set (the current data set will be used if empty).

The specified trace points will show as square symbols on your screen; additionally found points are shown using cross symbols. Selected specified points appear in another color than unselected data points (see options). You can select and manipulate your specified points.

Press Ctrl+L to toggle connecting your data points with lines.

See also: Defining your axes, Manual pick mode, Scan for symbols mode.

Adjusting data points
Axes definition
Background color
Bitmap file
Black and white filter
Creating a data set
Data files
Data format
Data sets
Defining your axes
Deleting data
Editing data
Erasing data
Exporting data
Filtering your image
Getting started
Graphics Interchange File format (GIF)
Gray scale filter
Highlighting edges of colored regions
Hot keys
Importing images from other applications
Inverting colors
JPEG files
Keyboard shortcuts
Lines between data points
Logarithmic axes
Manipulating data
Manually picking points
Marker color
Marker size
Moving data points
New data set
New window
Opening documents
Opening images
Pasting images
Picking points
Portable Network Graphics (PNG)
printf format strings
Reducing color resolution
Removing data
Removing noise
Resampling data
Saving documents
Saving your image
ScanIt Document files (SID)
Scanning for symbols
Scanning points on a curve
Selected marker color
Selecting data
Shortcut keys
Significant digits
Sorting data
Starting a document
System requirements
Tagged Image File Format (TIF)
Text files
Trace recursion level
Using your data in other applications
Zoom View
 Welcome to ScanIt
 The document windows
 Storing and loading documents
 The Zoom View
 Preparing your image
 Gathering data
 Defining your axes
 Manual pick mode
 Trace curve mode
 Scan for symbols mode
 Manipulating data
 Using data in other applications
 Keyboard shortcuts
 Disclaimer and license