I think, Don is asking where do I divide a floating number by zero in load flow calculations.
I am using DC load flow calculations and dividing circuit reactance with number of circuits. Normally, in the incidence matrix, when there is no connection between two buses, both reactance and no. of circuits are zero. However, I am calculating load flow with one of the transmission lines out of service. Instead of setting both reactance and no. of circuits to zero, I just set the no. of circuits to zero and hence getting an infinity. Thanks, PT On Mon, May 20, 2013 at 9:17 AM, Raul Miller <[email protected]> wrote: > I don't understand this question. > > Can you restate it? > > In other words are you asking whether floating point numbers are valid > in your code? Or are you asking why someone would divide epsilon by > zero? Or are you trying to express a problem? Or is it something > else? > > That said, my generic reaction is that if you have practical issues > where the distinction between 0%0 and 1e_256%0 matters that probably > means your model is unstable. > > Thanks, > > -- > Raul > > On Sun, May 19, 2013 at 7:41 PM, Don Kelly <[email protected]> wrote: > > On my machine (64 bit athlon) using J602 i find that 0%0 will give 0. > BUT > > (0+1e_256)%0 will give infinity. > > > > A question that I have is that in dealing with power system matrices- > where > > does such a situation occur in manipulating the matrices in load flow or > > converting Y to Zbus matrices for a realistic model? The only case > would be > > one where one might like to connect two busses together through a "0" > > impedance link in order to represent a case where switching is done to > > connect/disconnect them. > > > > > > Don Kelly > > > > > > On 17/05/2013 8:04 PM, Brian Schott wrote: > >> > >> I remember that years ago there was a verb to divide 0 by 0 and produce > _, > >> but I cannot find it anywhere. It was probably not the one I have > produced > >> tonight, but here it is, anyhow. > >> > >> div =: 0:`%@.(+.&*) > >> 0 1 2 3 3 _6 div 0 1 _5 6 0 0 > >> 0 1 _0.4 0.5 _ __ > >> > >> > >> > >> > >> > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
