.TITLE DATAN2 COMPUTE ARCTANGENT FOR DOUBLE ARGUMENTS (TAN A1/A2)
/COPYRIGHT 1970, DIGITAL EQUIPMENT CORP., MAYNARD, MASS.
	/EDIT 3 8--14--70
       .GLOBL DATAN2,.DA,.AO,.AT,.DD,.AP,.AQ,.BA / *** DDS FEB69 ***
/	    CALLING SEQUENCE
/      JMS*   (DTAN2)	SUBR CALL
/      JMP    .+3		SUBR RETURN
/      CAL/XCTADDR(1)	ADDR OF ARG1
/      CAL/XCTADDR(2)	ADDR OF ARG2  (XCT IF INDIRECT)
/
DATAN2 CAL    0	         /ENTRY-EXIT
       JMS*   .DA	         /GET ARGUMENT (.DA)
       JMP    DTN203
DTN201 CAL    0	         /ARG1
DTN202 CAL    0	         /ARG2
DTN203 JMS*   .AO	         /LOAD DOUBLE (.AO)
       .DSA   DTN201+400000  / (ARG1)
       JMS*   .AT	         /DIVIDE DOUBLE (.AT)
       .DSA   DTN202+400000  / (ARG1/ARG2)
       JMS*   .DD	         /COMPUTE ARCTANGENT (.DD)
	ISZ	DTN202	/ *** DDS FEB69 ***
	LAC*	DTN202	/ *** DDS FEB69 ***
	SMA		/ *** DDS FEB69 ***
       JMP*   DATAN2         /EXIT
	JMS*	.AP	/ *** DDS FEB69 ***
	.DSA	DTN204	/ *** DDS FEB69 ***
	JMS*	.AO	/ *** DDS FEB69 ***
	.DSA	DTN205	/ *** DDS FEB69 ***
	ISZ	DTN201	/ *** DDS FEB69 ***
	LAC*	DTN201	/ *** DDS FEB69 ***
	SPA		/ *** DDS FEB69 ***
	JMS*	.BA	/ *** DDS FEB69 ***
	JMS*	.AQ	/ *** DDS FEB69 ***
	.DSA	DTN204	/ *** DDS FEB69 ***
	JMP*	DATAN2	/ *** DDS FEB69 ***
DTN204	0		/ *** DDS FEB69 ***
	0		/ *** DDS FEB69 ***
	0		/ *** DDS FEB69 ***
DTN205	000002		/ *** DDS FEB69 ***
	311067		/ *** DDS FEB69 ***
	552000		/ *** DDS FEB69 ***
       .END