IGOR Pro Developers Working Group

From canSAS


  • Jan Ilavsky (APS)
  • Andrew Jackson (NIST)
  • Steve Kline (NIST)
  • Ken Littrell (ORNL)
  • Andy Nelson (ANSTO) (chair)


The canSAS-VIII meeting in April 2015 decided that the activities of this working group were complete and that further meetings of this group were not needed. This page should be retained as an archive.

USAXS (= "Indra2") data naming structure APS USAXS instrument can operate with either slit smeared and 2-D collimated geometry. Practically for all samples with meaningful thickness the intensity data are absolutely calibrated ([1/cm]). Errors for intensity are always estimated. Q units are 1/A. The Q resolution (width of bin in Q) is same for all points - 1e^-4 [1/a] and therefore is not reported. Q-bin smearing is practically not necessary. Significant fraction of samples exhibit multiple scattering effects for which we attempt to make correction for absolute intensity calibration. Most of data processing parameters are stored in keyword list in the wave note.

List of wave names and description: Folder name in Igor is the sample name - and sample name and description is included in the wave note of all waves. SMR_Int, SMR_Error, SMR_Qvec .... slit smeared Intensity, Error, and Q. Slit length is in the wave note. M_SMR_Int, M_SMR_Error, M_SMR_Qvec.... slit smeared data, absolute intensity corrected for multiple scattering effects. DSM_Int, DSM_Error, DSM_Qvec .... de-smeared (using Lake method) or 2-D collimated data. M_DSM_Int, M_DSM_Error, M_DSM_Qvec .... de-smeared or 2-D collimated data, absolute intensity corrected for multiple scattering effects.

Nika data naming structure Nika is universal package for reduction of 2D data into 1D "lineouts" for Igor Pro. It is used mostly for X-ray SAXS and WAXS instruments (synchrotron & desktop). It can output data either as function of Q, angle, or d-spacing. It can generate either maximum number of Q points (one Q per pixel on detector) or re bin the points to smaller number, or re bin the points to semi-logarithmic distribution in Q. It provides width of bin in Q as additional wave with each data for tools which enable accounting for Q-bin smearing. To identify the sector geometry (or circular average), "_ending" is attached to the end of output wave names: "_C" circular average "_Angle_HalfWidth" sector average around direction of Angle with sector +/- HalfWidth example: "_10_5" average around 10 degrees direction with sector 10 degrees (+/- 5 degrees) wide. Or to use another description - sector between lines in 5 degrees and 15 degrees azimuth on the detector.

List of data types Sample name is used as folder name and each folder contains data from only one sample & sector. "QRS" namings structure: q_sampleName_ending .... Q with units in [1/A] r_sampleName_ending .... Intensity with units 1/cm (if data are calibrated) s_sampleName_ending .... Error for intensity (statistical error from averaged pixels) w_sampleName_ending .... Q bin width optionally instead of Q one can use: t_sampleName_ending .... Two theta value in degrees d_samplename_ending .... d-spacing value in A