Changeset 1539

Timestamp:

Aug 13, 2004, 2:58:46 PM (22 years ago)

Author:

jhoblitt

Message:

date and time section formatting

File:

• trunk/doc/pslib/psLibSDRS.tex (modified) (10 diffs)

trunk/doc/pslib/psLibSDRS.tex

@@ -1 @@
-%%% $Id: psLibSDRS.tex,v 1.71 2004-08-14 00:38:27 jhoblitt Exp $
+%%% $Id: psLibSDRS.tex,v 1.72 2004-08-14 00:58:46 jhoblitt Exp $
 \documentclass[panstarrs,spec]{panstarrs}
 
@@ -3029 +3029 @@
 \subsection{Dates and times}
 
+\subsubsection{Overview}
+
 We require a collection of functions to manipulate time data.  These operations
 primarily consist of conversions between specific time formats.  Internally,
@@ -3034 +3036 @@
 has been extended to track the time system being represented.
 
+Conversion from one time system to another is achived by converting first to
+TAI and then to the destination type.  This allows arbitarily many time system
+to be supported by merely add functions to convert to and from TAI.
+
+\subsubsection{Generic Data Structures}
+
 \begin{verbatim}
 typedef enum {
-    PS_TIME_TAI,                    /* seconds since 1970-01-01T00:00:00Z (Gregorian) */
-    PS_TIME_UTC,                    /* seconds since 1970-01-01T00:00:00Z (Gregorian) */
-    PS_TIME_UT1,                    /* seconds since 1970-01-01T00:00:00Z (Gregorian) */
-    PS_TIME_LST,                    /* seconds since 1970-01-01T00:00:00Z (Gregorian) */
+    PS_TIME_TAI,                    ///< seconds since 1970-01-01T00:00:00Z (Gregorian)
+    PS_TIME_UTC,                    ///< seconds since 1970-01-01T00:00:00Z (Gregorian)
+    PS_TIME_UT1,                    ///< seconds since 1970-01-01T00:00:00Z (Gregorian)
+    PS_TIME_LST,                    ///< seconds since 1970-01-01T00:00:00Z (Gregorian)
 } psTimeType;
 
 typedef struct {
-    psU64            sec;           /* seconds */
-    psU32            nsec;          /* nanoseconds */
-    psTimeType       type;          /* type of time */ 
+    psU64            sec;           ///< seconds
+    psU32            nsec;          ///< nanoseconds
+    psTimeType       type;          ///< type of time
 } psTime;
 \end{verbatim}
+
+\subsubsection{Current Date and Time}
 
 A number of functions are provided to get the current time in a particular time
@@ -3061 +3071 @@
 \end{verbatim}
 
+\subsubsection{Automatic Date and Time Type Conversion}
+
 When converting to a time system the source time system is automaticaly
 converted to TAI and then from TAI to the destination type.
@@ -3073 +3085 @@
 \end{verbatim}
 
+\subsubsection{Date and Time Formatting}
+
 A collection of functions convert from the \code{psTime} types to various
 external formats.  Note that ISO8601 format is "YYYY-MM-DDThh:mm:ss,sZ"
@@ -3081 +3095 @@
 \end{verbatim}
 
+\subsubsection{Date and Time Parsing}
+
 A related collection of functions convert from external formats to a
 \code{psTime} type.
@@ -3088 +3104 @@
 psTime *psParseTimeval(psTimeType type, struct timeval *input);
 \end{verbatim}
+
+\subsubsection{Date and Time System Support}
 
 All \code{psTime} types must be able to be converted to to the TAI type.
@@ -3099 +3117 @@
 
 A utility function provides the current time from the system clock, in correct TAI units:
+
 \begin{verbatim}
 psTime *psTAIToUT1(psTime *time);
@@ -3109 +3128 @@
 \end{verbatim}
 
+\subsubsection{Utility Functions}
+
 A number of utility functions is needed for type conversion.
 
@@ -3140 +3161 @@
 double psGetUT1Delta(psTime *tai);
 \end{verbatim}
+
+\subsubsection{Date and Time Math}
 
 Time math is only done on the \code{psTime} TAI type.