circuit {ResistorArray} | R Documentation |
Given a conductance matrix and a vector of potentials or current input
values at each node (NA
being interpreted as “unknown”),
this function determines the potentials and currents over the whole
circuit.
circuit(L, v, currents=0, give.internal)
L |
Conductance matrix |
v |
Vector of potentials; one element per node of the conductance
matrix. Elements with NA are interpreted
as “free” nodes, that is, nodes that are not kept at a fixed
potential. The potential of these nodes is well defined by the other
nodes in the problem |
currents |
Vector of currents fed into each node. The only
elements of this vector that are used are those that correspond to a node with free potential (use NA for nodes that are at a
specified potential). The idea is that each node has
either a specified voltage, or a specified current
is fed into it; not both.
Observe that feeding zero current into a node at free potential is perfectly acceptable (and the usual case). |
give.internal |
Boolean, with TRUE meaning to return also
a matrix showing the node to node currents, and default FALSE
meaning to omit this. |
A list of 2 or 4 elements, depending on argument
give.internal
is FALSE
or TRUE
.
potentials |
A vector of potentials. Note that the potentials of the
nodes whose potential was specified by input argument v
retain their original potentials; symbolically
all(potentials[!is.na(v)] == v[!is.na(v)]) . |
currents |
Vector of currents required to maintain the system
with the potentials specified by input argument v |
internal.currents |
Matrix showing current flow from node to
node. Element [i,j] shows current flow from node i to
node j . |
power |
The power dissipated at each edge |
total.power |
Total power dissipated over the resistor network |
The SI unit of potential is the “Volt”; the SI unit of current is the “Ampere”
Robin K. S. Hankin
#reproduce first example on ?cube: v <- c(0,rep(NA,5),1,NA) circuit(cube(),v) circuit(cube(),v+1000) # problem: The nodes of a skeleton cube are at potentials # 1,2,3,... volts. What current is needed to maintain this? Ans: circuit(cube(),1:8) #sanity check: maintain one node at 101 volts: circuit(cube(),c(rep(NA,7),101)) #now, nodes 1-4 have potential 1,2,3,4 volts. Nodes 5-8 each have one #Amp shoved in them. What is the potential of nodes 5-8, and what #current is needed to maintain nodes 1-4 at their potential? # Answer: v <- c(1:4,rep(NA,4)) currents <- c(rep(NA,4),rep(1,4)) circuit(cube(),v,currents)