.lt>The following description refers to the sample fortran programEPDS:[RAD.XG.SAMP]XGFUNC.FOR, this file is the skeleton from which allother applications are written.GSkeleton program for all XG databases, with full generalized variables.4Must modify or replace all places indicated with @@4Look carefully at all options indicated by @OFThe sections beginning with a "C_" are standard documentation sectionsLand you should follow the indicated format. The C_Argument section contains 7compileable specifications of the subroutine arguments.KThis routine is called by XGDATA at 5 steps indicated by the argument IQ:@1) After selection of the database and time range to be accessed,2) At the start of each observation sequence=3) With a set of up to 120 "rows" of data from that seqence. . This continues until a sequence is completed.I If constraints have been applied then the ICK variable is set negative< if that ick of data did not pass all constraints applied.4) At the end of each sequence35) After completion of all sequences in time range.KIt is commonly desireable to do analysis on the basis of a "sequence". For Gthe Viking databases, a sequences correspond to a continuous period of Lobservations, typically 1 to 40 minutes long, with a specific objective and "the instrumnent in a single mode. 6Places where you can insert new code are indicated by:BC-#-vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvC Insert your code here.BC^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^BReturn code IR = 0 yields normal progression through this routine.HOptionally, at some some steps you can set IR to the step (IQ) you wish 3to go to immediately. The valid cases for this are: IQ_now IR!2 2 = goto start of same sequence! 4 = goto end of current sequence43 4 = go to step 4 (end of sequence) NOT IMPLEMENTED: 5 = go to step 5 (terminate data search) NOT IMPLEMENTED4 2 = restart this sequence( 5 = goto step 5 (terminate data search)JXGDATA will automatically open a print file named program_name.PRT, where <program_name is that part of PROGNM that preceeds the colon.=Before compiling this routine, do the following DCL command:  @PDS:[RAD.COM]RADINITFTo LINK, copy and modify the file XG$SMP:LINK.COM as directed therein.2Then, copy into your directory XG$SMP:XGFUNC.PDF, ( rename it, and modify it if necessary.6To RUN, do @PDS:[RAD.COM]RADENABLE and then RADSTART.J Then, at the command level in TAE, do TUTOR [your directory]Program_name.el