Differences

This shows you the differences between two versions of the page.

--- gedfunction [2023/10/11 14:32] – created admin
+++ gedfunction [2023/10/11 15:22] (current) – admin
@@ Line 9: / Line 9: @@
 (nbsp)(nbsp)where:
-(nbsp)(nbsp)//n//: level, 2 or 3\\
+(nbsp)(nbsp)(bcircle) //n//: level, 2 or 3\\
-(nbsp)(nbsp)//m//: format, 1, 3, 4 or 5\\
+(nbsp)(nbsp)(bcircle) //m//: format, 1, 3, 4 or 5\\
-(nbsp)(nbsp)//datatype//: see the quick reference tables on the main page \\
+(nbsp)(nbsp)(bcircle) //datatype//: see the quick reference tables on the [[ged_docs|main page]] \\
+[[ged_examples|Examples]]
+==== IDL doc_library comment ====
+<code>
+ Function GED  - Get Erne Data (lev-2 and lev-3)
+ Version: 1.5
+ Description:
+    This is a general envelope routine for reading and pre-processing of various ERNE data.
+    Typically GED will open various GUI-windows to let user interactively specify data and preprocessing.
+    This can be modified by keywords.
+ Calling sequence:
+    d=ged()
+ Output:
+    Typically an array of structures. The exact structure type depends on the input data type in question and the
+    set of possible filter functions.
+ Keywords:
+    FILENAMES     = List of input file names
+                    If not set the 'datafilename'-procedure is started letting the user select the files interactively.
+    GED_FFUNCS    = List of filter functions
+                    After the data is read we have an array of data records of a specific ERNE data type.
+                    If required this data set will be fed through series of caller supplied filter functions.
+                    The filtering is done stepwise by feeding each filter function with the output of the previous
+                    one.
+                    The first filter function in the list must naturally accept an array of records of
+                    the nominal ERNE data type as read from the data files. The return of the last filter
+                    function is used as the output of this ged -function.
+                    Each filter function has to be of the type: ff(din,[KEYWORDS]), where din is the input
+                    data (typically an array of records).
+                    Keywords (if any) are relayed to the filter functions using IDL:s '_REF_EXTRA'-keyword.
+                    Thus they can be issued in the ged-function call as any other keyword. Requirement is of course
+                    that the keyword identifiers are unique (or compatible) between various procedures that will
+                    be called.
+                    There are two schemes for filter function execution:
+) 'PHA-schema'      - filtering is done after each file is read. There is a memory
+                                             problem when analysing long periods of PHA-data. With a suitable
+                                             filter, unnecessary PHA-events can be discarded at this stage
+                                             keeping the resulting output data array at a reasonable size.
+) 'Spectral-schema' - filtering is done only after the whole data set has been read.
+                                             Spectral data usually needs to cross file boundaries when time-
+                                             integrating data. The typical filtering in this case consists
+                                             of energy-integration, which will be done on the time-integrated
+                                             data i.e., after all the data has been read.
+                                             Spectral data is much less space consuming than PHA-data
+                                             and the time integration further reduces the size of the
+                                             data set, so this should work fairly well.
+                    The scheme is automatically desided based on the data type in question.
+    GED_NFILERECS = Returns the number of data records from each input file
+                    This is primarily meant for assisting in finding corresponding PHA-events between
+                    lev-2 and lev-3 PHA data.
+                    Not implemented for spectral data.
+    GED_CATCHERR  = If set (to nonzero) the errors will be catched by ged.
+                    The reason for this option is the handling of IDL errors when ged is called via
+                    a batch file by the java web interface.
+                    The error handling is very simple: in case of errors the copy of !ERROR_STATE system
+                    variable structure is returned.
+                    It is assumed that when the keyword has been set the caller checks the type of the result
+                    and acts accordingly. For example:
+                      d = ged(/GED_CATCHERR)
+                      if tag_names(d,/structure_name) EQ '!ERROR_STATE' then ...
+                    Note: this will not affect the handling of the non fatal math errors.
+ Version history:
+.5     2007-01-31 (ER)
+) Updated the naming of the LED level-3 direction spectra reader functions.
+) Updated the file-iteration scheme for the led direction spectra.
+) Removed checking fo file types '.pha' from lev-3 reader function name
+             construction. There are no such file types.
+.4     2004-12-14 (ER)
+          Added new internal keyword flag 'GED_1ST' that will be set on first call of
+          a reader and filter functions. Specifically this is for the readers like
+          'ged_l3_corr', that on request returns auxiliarity paramaters as a keyword
+          array. This will enable clearing of the array on first call and adding
+          the data at the end of the array on subsequent calls.
+.3     2004-10-07 (ER)
+          Changed to take use of the ERNE-error messages. Specifically in case there are no files found
+          as a result to call of the function 'datafilename'.
+.2     2002-06-28 (ER)
+          Correction for error catching mechanism. It appeared that the '!ERROR_STATUS' contains fields
+          (especially the message fields) that seem to be implicit pointers. When we copied those fields
+          straight to the output error record, their contents were sometimes changed with further errors
+          and warnings.
+.1     2002-06-26 (ER)
+          - Added keyword 'GED_CATCHERR' and the accompanying code.
+          - Changed names of the other ged specific keywords 'GED_...' format in accordance to the
+            general naming convention.
+.0     2002-05-21 (ER)
-Examples
+          Original version.
+</code>