ImageJ/Fiji: Iteration through and printing in results table

Question

I have a problem with my Jython-Fiji Plugin:

IJ.run("Set Measurements...", "area centroid perimeter shape feret's area_fraction     redirect=None decimal=6")
IJ.run("Analyze Particles...")
rt = ResultsTable.getResultsTable()

for roi in RoiManager.getInstance().getRoisAsArray():
  a = rt.getValue("Feret", row)
  b = rt.getValue("MinFeret", row)
  nu= 1
  L = 1
  p = 1
  row = row + 1
  s = (math.pi/4) * (1/(nu*L)) * math.pow(a, 3) * math.pow(b, 3) / (math.pow(a, 2) + math.pow(a, 2))*p
  rt.addValue("S", s)
rt.show("Results") 

Normaly this should add a new column (named S) in my oppinion with the values of s. Unfortunatly only the last s value shows up in the column, while all other rows of this column are filled with 0. I definetly missed something, but at the moment I dont know what. Thanking you in advance!

Answer 1

To make your code run, I had to add import math and row=0 at the beginning.

I then replaced the ResultsTable.addValue() function call by ResultsTable.setValue() with adding the current row parameter. See the API documentation for details.

import math
IJ.run("Set Measurements...", "area centroid perimeter shape feret's area_fraction     redirect=None decimal=6")
IJ.run("Analyze Particles...")
rt = ResultsTable.getResultsTable()
row=0
for roi in RoiManager.getInstance().getRoisAsArray():
  a = rt.getValue("Feret", row)
  b = rt.getValue("MinFeret", row)
  nu= 1
  L = 1
  p = 1
  s = (math.pi/4) * (1/(nu*L)) * math.pow(a, 3) * math.pow(b, 3) / (math.pow(a, 2) + math.pow(a, 2))*p
  rt.setValue("S", row, s)
  row = row + 1
rt.show("Results")

Hope that helps.