Waterfall Plot: multiple XYpair data sets vs. z
saalvarez
Fri, 07/08/2011 - 01:08 pm
I have a question regarding waterfall plots. I am analyzing scattering data and I am studying how the intensity in the pattern varies with different angles. I am using an Igor PRO customized package that allows me to obtain the intensity over different sectors of the image ( I define the sector properties e.g. width, angle between sectors,etc) and the output for each sector is an intensity wave and a scattering vector q (reciprocal space vector). I have taken sector profiles over a 90 degrees range and now I would like to plot intensity vs q vs angle.
I have read the information on the manual on waterfall plots, and this is what I believe I have to do: (please correct me)
xdata= q
ydata= angle
zdata= intensity
1- Change XY pair data to waveform data by setting the x scale of my intensity data using the q data (interpolation).
2- Concatenate all my waves into a matrix
3-Set the y scale of my matrix ( which should be pretty easy as my angle increases from 180 to 275 every 5 degrees)
Now, here is my question: The center of my sector profiles is on the top of the image, and therefore, the x range of my q waves are different although the number of points is the same for all of them. All waves have 498 points, but, for example, the q wave at 180 degrees the x values range from 0 to 2 (shortest distance from the center) while the q wave at 275 goes from 0 to 3 (longest distance from the center). After I change my XY pairs to waveform data, can I still concatenate into a matrix if they have different xranges but same number of points? (It just occurred to me while writing this to use the min and maximum x values for the wave with the longest x range and apply it to the scaling of the rest of the q waves I have.... would this work? )
I was reading in the forum and I have seen a lot of suggestions about using Gizmo 3D, which I have never used. I can probably read about it in the manual, but would this be easier than trying to do a waterfall plot? (would I still have to rescale my waves to use Gizmo 3D?)
Thanks in advance!
Steven
A waterfall plot is straightforward but the tradeoff is in the effort to create the matrix data for the input and the appearance of the graph.
I heard people say that Gizmo is difficult to use but I don't share that opinion. If you want to learn more about Gizmo, start here: http://www.wavemetrics.com/products/igorpro/videotutorials.htm at the bottom of the page.
Using Gizmo you have many choices for representing your data. If you simply want to display data as you described above start by creating a triplet wave:
Concatenate {xdata,ydata,zdata}, tripletWave
Now you can plot the tripletWave in Gizmo as a path, scatter or assorted other combinations. If you want to get more creative and display your data as a function of a true angle or as a 3D distribution of iso-intensities, etc., feel free to contact me directly with the details of your application.
A.G.
WaveMetrics, Inc.
July 8, 2011 at 02:27 pm - Permalink