Although Datasqueeze is primarily designed to read in a 2D array of data from an area detector,
it is also possible to read in x-y data files. These could be generated
by the "Save Plot Data as Ascii File" or "Export Plot Data" menu items, or
created by another application. This data set can then be analyzed via least-squares fits or powder indexing.
- Allowed formats include one of the following:
- Two-or three column ascii, separated by tabs, commas, or spaces. This includes .csv
files exported by Microsoft Excel®. The first column is the independent variable
(most often Q or 2θ), the second is the intensity, and the optional third column is the uncertainty
in the intensity. If no intensity is provided, Poisson statistics are assumed.
The file can start with multiple header lines containing metadata.
- PLV. This is the format created by the Xpowder® powder diffraction analysis application (www.xpowder.com).
- Ascii profile (.pro or .rfl): first line with start 2θ, delta 2θ, stop 2θ, and then multiple intensity values per line.
- Sietronics® CPI format.
- canSAS format for small-angle data (www.cansas.org).
- When the menu item is activated, you get a new window.
- Start by clicking on Browse to choose an input file. When this is done,
you will either get an error message or the first few lines of the file in white box.
In most cases the independent variable number of header (skipped) lines will be auto-detected.
The number of lines to read is set to the total number of valid data points.
- The drop-down "Independent Variable" box allows you to choose the name of the independent variable.
- "Lines to Skip" is the number of non-data header lines at the top of
the file, and if set to be greater than the number of header lines will also cause the
interface to skip over the first few lines of data. (The lines to read can only be changed after hitting the Browse button).
- "Lines to Read" is the number of data points to be plotted,
which is normally the total number of data points in the file but could be smaller.
- You can choose whether the X and Y axes should be plotted on linear or log scales.
(The data in the file itself should always be on a linear, or absolute scale).
- You can also redefine the wavelength that was used for this data set.
- Then click on Read. If the file was correctly read in, you should be able to click on Apply,
at which point your data will be plotted.
- To change the details of the plot, click the Advanced Features button which brings up the same Advanced Plot
Features window which is described in more detail in the Plot Panel section.
- Click on Cancel/Done to close the window.
- The shortcut key is (ctrl)-Shift-I (or Apple-Shift-I on Macintosh). In Batch mode see the IMPORT1D option.
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