FTN4,L C C C C C C CC************************************************************ C (C) COPYRIGHT HEWLETT-PACKARD COMPANY 1978. ALL RIGHTS * C RESERVED. NO PART OF THIS PROGRAM MAY BE PHOTOCOPIED, RE- * C PRODUCED, OR TRANSLATED TO ANOTHER PROGRAM LANGUAGE WITH- * C OUT THE PRIOR WRITTEN CONSENT OF HEWLETT-PACKARD COMPANY. * CC************************************************************ C C C C NAME: GANG4 C SOURCE: 92840 - 18163 C RELOC: 92840 - 16021 C C C CC*********************************************************** SUBROUTINE GANG4(IGCB,AMU,ANDC,BUFR) +,92840-16021 REV.2013 791129 C************************************************************** C GANG4 CONVERTS AN MU ANGLE INTO AN NDC ANGLE. C C AMU = ANGLE IN MACHINE UNIT RADIANS. C ANDC= ANGLE IN NDC COORDINATE RADIANS. (RETURNED) C BUFR = MINIMUM 8-WORD UTILITY BUFFER. C************************************************************** INTEGER IGCB(1) REAL AMU,AMU,BUFR(1) REAL PI INTEGER IREAD DATA PI/3.14159/ DATA IREAD/1/ C************************************************************* C CALCULATE THE ANGLE IN NDC COORDINATES. THE ALGORITHM C IS AS FOLLOWS: C XMU=COS(AMU) YMU=SIN(AMU) C*********************************************************** C GET THE CONVERSION FACTORS. C 20 CONTINUE CALL GCBIM(11,1,BUFR,0,IREAD) C**************************************************************** C CONVERT TO NDC UNITS. C XNDC=XMU/BUFR(1) YNDC=YMU/BUFR(3) C**************************************************************** C TAKE THE ARCTAN TO GET THE MU ANGLE. C CORRECT THE NDC ANGLE TO BE IN THE SAME QUADRANT AS THE MU ANGLE. C ANDC=ATAN2(YNDC,XNDC) RETURN END