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</o:shapelayout></xml><![endif]--></head><body lang=EN-NZ link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>So, I’m delving into the PREDICT operations in the RPN, and have found something unexpected.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>There are two ways of specifying the shift offsets – as a (positive) count of shifts and a list; or as a negative count and a base shift.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><div style='mso-element:para-border-div;border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt;background:#F3F3F3'><p class=ExampleCxSpFirst style='background:#F3F3F3'><span lang=X-NONE>CDEF:predict1=</span>172800,<span lang=X-NONE>86400</span>,0<span lang=X-NONE>,</span>3<span lang=X-NONE>,3600,x,PREDICT<o:p></o:p></span></p><p class=ExampleCxSpLast style='background:#F3F3F3'><span lang=X-NONE>CDEF:predict2=86400,-</span>3<span lang=X-NONE>,3600,x,PREDICT</span><o:p></o:p></p></div><p class=MsoNormal><span lang=X-NONE><o:p> </o:p></span></p><p class=MsoNormal>My tests (using 1.4.trunk) indicate that the two above have identical behaviour. My question is, is this intended? In particular, when giving a negative shift count, should the resulting list of shifts be based at 0? <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Given this:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>CDEF:predict=s,-3,w,x,PREDICT<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I had expected to get shifts of s, 2s and 3s. Instead I get 0, s and 2s. Is this intentional, or a feature?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>As a corollary, it means that these two lines are also equal for ANY value of s<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><div style='mso-element:para-border-div;border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt;background:#F3F3F3'><p class=ExampleCxSpFirst style='background:#F3F3F3'><span lang=X-NONE>CDEF:predict1=</span>s<span lang=X-NONE>,</span>-1<span lang=X-NONE>,3600,x,PREDICT<o:p></o:p></span></p><p class=ExampleCxSpLast style='background:#F3F3F3'><span lang=X-NONE>CDEF:predict2=x,</span>3600,TRENDNAN<o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Steve<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b>Steve Shipway<o:p></o:p></b></p><p class=MsoNormal>University of Auckland<o:p></o:p></p><p class=MsoNormal><i>UNIX Systems Design Team Lead<o:p></o:p></i></p><p class=MsoNormal><span style='font-size:10.0pt'>s.shipway@auckland.ac.nz<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt'>+64 (9) 3737 599 ext 86487<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>