...

An ISPyB project works in a similar way to a ICAT project, but shows more meta data. Again, only for beamlines the support the ISpyB database.

6. 3D Data Slicing

There are now tools (not plot tools) for slicing 3D data sets in different ways. This can be done in the Data Browsing Perspective (yellow box cutter icon) or DExplore (Hyper3D). DAWN 1.2 contains the first version with this view (In DExplore).

The 3D slicing view was specifically designed to work with hyperspectral image datasets (stacks of images where each images corresponds to a different wavelength and a single pixel traced down the stack is a spectrum), but it also works well for other stacks of images.O

• Open the example file 315029.dat.
• Select the Pilatus dataset, and the yellow box cutter icon (or Hyper3D from the inspector tab if in DExplore)
  
• What shape is this dataset?
  
  

Image Added

The two plots in this view show different sections of the 3D pilatus dataset. The image shows the dimensions perpendicular to the dimension selected as the trace-coord. The actual image shown is an integration of the image stack over the window shown in the trace plot on the right.

• Move the region on the right hand plot, what happens to the image on the left hand plot?

The trace in the right hand plot shows the average of all the traces corresponding to the pixels selected by the box region on the image.

• Move the region on the left hand plot, what happens to the trace on the right hand plot?
• Add more regions to the image, using the Create New Profile toolbar action. Traces can be exported to a .dat file using the Export... toolbar action.

Experiment with your own 3D datasets (or ask for more exciting datasets), the instructors in the class will be happy to help with any questions/problems you might have.

Test Yourself

1. Describe three different Regions of Interest, what they look like and how they are drawn.
2. What shape ROI does the Radial profile tool work with?
3. How do you stop artifacts in an image (such as the spacing between detector plates in a Pilatus image)  affecting profiles of the image?
4. What are the colors of the edges of a perimeter box profile?
5. What approximations are made by the peak fitting tool?
6. What is the distance between the two highest peaks in Column_1 of metalmix.mca (total distance, dx, and dy).
7. "dataset_1" has the shape [100,200,300], what Expression should would give a [100,200] image which is the mean of the other axis?
8. What 5 things can be saved in an exported nexus file?

...