.TITLE ATAN2  COMPUTE ARCTANGENT FOR REAL ARGUMENTS (ATAN2 A1/A2)
/COPYRIGHT 1970, DIGITAL EQUIPMENT CORP., MAYNARD, MASS.
	/EDIT 3  8--14--70
       .GLOBL ATAN2,.DA,.AG,.AL,.ED,.AH,.AI,.BA / *** DDS FEB69 ***
/	    CALLING SEQUENCE
/      JMS*   (ATAN2)	SUBR CALL
/      JMP    .+3		SUBR RETURN
/      CAL/XCTADDR(1)	ADDR OF ARG1
/      CAL/XCTADDR(2)	ADDR OF ARG2 (XCT IF INDIRECT)
/
ATAN2  CAL    0	         /ENTRY-EXIT
       JMS*   .DA	         /GET ARGUMENT (.DA)
       JMP    ATN203
ATN201 CAL    0	         /ARG1
ATN202 CAL    0	         /ARG2
ATN203 JMS*   .AG	         /LOAD REAL (.AG)
       .DSA   ATN201+400000  / (ARG1)
       JMS*   .AL	         /DIVIDE REAL (.AL)
       .DSA   ATN202+400000  / (ARG1/ARG2)
       JMS*   .ED	         /COMPUTE ARCTANGENT (.ED)
	ISZ	ATN202		/ *** DDS FEB69 ***
	LAC*	ATN202		/ *** DDS FEB69 ***
	SMA			/ *** DDS FEB69 ***
       JMP*   ATAN2          /EXIT
	JMS*	.AH	/ *** DDS FEB69 ***
	.DSA	ATN204	/ *** DDS FEB69 ***
	JMS*	.AG	/ *** DDS FEB69 ***
	.DSA	ATN205	/ *** DDS FEB69 ***
	ISZ	ATN201	/ *** DDS FEB69 ***
	LAC*	ATN201	/ *** DDS FEB69 ***
	SPA		/ *** DDS FEB69 ***
	JMS*	.BA	/ *** DDS FEB69 ***
	JMS*	.AI	/ *** DDS FEB69 ***
	.DSA	ATN204	/ *** DDS FEB69 ***
	JMP*	ATAN2	/ *** DDS FEB69 ***
ATN204	0		/ *** DDS FEB69 ***
	0		/ *** DDS FEB69 ***
ATN205	552002		/ *** DDS FEB69 ***
	311067		/ *** DDS FEB69 ***
       .END