HP-25 Two Variable Statistics - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: General Forum (/forum-4.html) +--- Thread: HP-25 Two Variable Statistics (/thread-18762.html) |
HP-25 Two Variable Statistics - Matt Agajanian - 09-05-2022 03:21 AM Hi all. Am I missing something? After I enter x, y data pairs, when I press the mean or standard deviation button, I only see the calculation for the x values. Is there something I’m supposed to do to calculate those for y values? Also, R0, R1, R2, and R7 were available. So, since I could enter x, y data pairs, why wasn’t the calculation for Σ(y^2) in one of the spare registers? Thanks. RE: HP-25 Two Variable Statistics - Steve Simpkin - 09-05-2022 04:01 AM As William C Wickes has said on other HP calculator projects when asked why a feature was missing from a particular model, "Life is short and ROM is full". In the case of the HP-25, this is literally true. There was no room left in the HP-25's ROM to add *any* feature unless you removed a feature or were able to further optimize the code to make more room. https://www.hpmuseum.org/forum/thread-8536-post-75033.html RE: HP-25 Two Variable Statistics - Matt Agajanian - 09-05-2022 04:18 AM Thanks for letting me in on the details. Oddly enough, a rerun from one of my earlier posts. Thanks anyhow! Although… Is it correct to presume that when the 19/29 came about, HP had the technology to be able to incorporate several high level features--now two-variable state, indirect addressing, 98 program steps, 30 registers, three subroutine levels, labels, etc.? I presume when the 19/29 were developed, the technology was able to create such higher functionality in their calculators. RE: HP-25 Two Variable Statistics - Steve Simpkin - 09-05-2022 05:32 AM (09-05-2022 04:18 AM)Matt Agajanian Wrote: ... All of the features you mentioned (more or less) were present in one or more of the HP-65, HP-55 or HP-67 programmable models which were introduced before the HP-29C/19C so the technology for those features did exist previously at HP. https://www.hpmuseum.org/cgi-bin/compare.cgi?calc1=HP-65&calc2=HP-55&calc3=HP-25&calc4=HP-67&calc5=HP-29C&calc6=none&calc7=none&calc8=none&diff=ON |