Posted by
Wayne Rasband on
Dec 07, 2009; 1:38am
URL: http://imagej.273.s1.nabble.com/how-to-stop-the-freehand-lines-tool-at-a-set-distance-20-um-tp3690197p3690198.html
On Dec 6, 2009, at 7:02 AM, Matiar Jafari wrote:
> Dear ImageJ Listserv,
>
> I'm looking for a way to draw lines of a set length on
> ImageJ. I need to measure spines on dendrites every 20 um
> from the soma on dissociated neurons grown in tissue
> culture. I've tried using a modified Sholl analysis, but
> without the laminar constraints the dendrites grow with
> various curves. I would like to use the freehand lines tool
> to stop at 20 um as I trace along the dendrite.
Here is a tool that you can use to draw freehand lines of a specified
length. The default length of 20 can be changed by assigning a another
value to the 'maxLength' variable. The default length is 20um if the
image is scaled to micrometers. The online manual explains how to
install macro tools:
http://rsb.info.nih.gov/ij/developer/macro/macros.html#tools-wayne
macro "Set Length Line Tool - C00bL1de0L1ee1" {
maxLength = 20;
leftClick=16
i = 0;
xpoints = newArray(2000);
ypoints = newArray(2000);
getCursorLoc(x2, y2, z, flags);
xpoints[i]=x2; ypoints[i++]=y2;
while (true) {
getCursorLoc(x, y, z, flags);
if (flags&leftClick==0) exit();
if (x!=x2 || y!=y2) {
xpoints[i] = x;
ypoints[i] = y;
i++;
x2=x; y2=y;
xpoints2 = Array.trim(xpoints, i);
ypoints2 = Array.trim(ypoints, i);
makeSelection("freeline", xpoints2, ypoints2);
List.setMeasurements;
length = List.getValue("Length");
showStatus("length="+d2s(length,2));
if (length>=maxLength) exit;
}
}
}