Doug Goncz
Apr22-04, 02:38 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>I wrote:\n\n>ds^2 / dt^2 = c.d * (ds/dt)^2 + P.i / (ds/dt)+ F.g(s) + F.r\n\n(leaving out the m)\n\nThat is:\n\ns\'\' = c.d * s\'^2 + P.i * t\' + F.g(s) + F.r\n___________________________\n\nm\n\nWhere the right side is all over m, so\n\nF(s, s\' , s\'\', t\' ) = 0\n\nand reduction of order is in order as the independent variable, t, does not\nappear.\n\nCan any of you help me reduce the order?\n\nRemember F.g(s) is a lookup table function of s requiring numerical integration\nor differentiation to get an answer s(t) but still, with this symbolic step I\ncan speed up my solver many times.\n\nCan you help?\n\n\nYours,\n\nDoug Goncz ( ftp://users.aol.com/DGoncz/ )\n\nMy physics project at NVCC:\nhttp://groups.google.com/groups?q=dgoncz&scoring=d plus\n"bicycle", "fluorescent", "inverter", "flywheel", "ultracapacitor", etc.\nin the search box\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>I wrote:
>ds^2 / dt^2 = c.d * (ds/dt)^2 + P.i / (ds/dt)+ F.g(s) + F.r
(leaving out the m)
That is:
s'' = c.d * s'^2 + P.i * t' + F.g(s) + F.r
__{_________________________}
m
Where the right side is all over m, so
F(s, s' , s'', t' ) =
and reduction of order is in order as the independent variable, t, does not
appear.
Can any of you help me reduce the order?
Remember F.g(s) is a lookup table function of s requiring numerical integration
or differentiation to get an answer s(t) but still, with this symbolic step I
can speed up my solver many times.
Can you help?
Yours,
Doug Goncz ( ftp://users.aol.com/DGoncz/ )
My physics project at NVCC:
http://groups.google.com/groups?q=dgoncz&scoring=d plus
"bicycle", "fluorescent", "inverter", "flywheel", "ultracapacitor", etc.
in the search box
>ds^2 / dt^2 = c.d * (ds/dt)^2 + P.i / (ds/dt)+ F.g(s) + F.r
(leaving out the m)
That is:
s'' = c.d * s'^2 + P.i * t' + F.g(s) + F.r
__{_________________________}
m
Where the right side is all over m, so
F(s, s' , s'', t' ) =
and reduction of order is in order as the independent variable, t, does not
appear.
Can any of you help me reduce the order?
Remember F.g(s) is a lookup table function of s requiring numerical integration
or differentiation to get an answer s(t) but still, with this symbolic step I
can speed up my solver many times.
Can you help?
Yours,
Doug Goncz ( ftp://users.aol.com/DGoncz/ )
My physics project at NVCC:
http://groups.google.com/groups?q=dgoncz&scoring=d plus
"bicycle", "fluorescent", "inverter", "flywheel", "ultracapacitor", etc.
in the search box