Making HistogramMaking a 1D or 2D histogram from a table:Any type of numerical column can be used to make a histogram. In this window, X and Y are column names from which one makes histogram. If a "Weight" column is selected, then the value of each cell is incremented by the value of "Weight" column, otherwise by 1.TLMIN and TLMAX are the keywords usually used in an event file and are critical to making correct histograms. "Data Min" and "Data Max" are minimum and maximum values of the selected column and are dynamically calculated. One needs to supply Min, Max, Bin Sizes for both X and Y column (for 2D histogram, X only for 1D histogram). By default, TLMin and TLMax values are used for Min and Max. One can select a range of rows in the table for making histogram by providing a "Row Range". Or one can use selected rows in the table window for making histogram by checking "Use selected rows" checkbox. "Make" button does the following procedures:
1D histogram:By selecting only the X column and/or Weight column, one can make a 1D histogram. Note:To retain the histogram, one must Save the file before closing it. fv will warn the user of this if the file has not been saved when closing it or exitting the program. Go to About fv. Pages maintained by Bryan Irby Send bug reports or feature requests via the FTOOLS help desk. HEASARC Home | Observatories | Archive | Calibration | Software | Tools | Students/Teachers/Public Last modified: Thursday, 16-Jul-2009 14:09:16 EDT HEASARC Staff Scientist Position - Applications are now being accepted for a Staff Scientist with significant experience and interest in the technical aspects of astrophysics research, to work in the High Energy Astrophysics Science Archive Research Center (HEASARC) at NASA Goddard Space Flight Center (GSFC) in Greenbelt, MD. Refer to the AAS Job register for full details. |