Nodal and mesh analysis 2

.PS
include(pstricks.m4)

scale=25.4

cct_init

vsp=25
hsp=25

define(`termrad_',`sourcerad_/4')
define(`terminal',`circle rad termrad_')

O: (0,0)

move to O

R3: resistor(up_ vsp); llabel(,R_3,)
{
  VA: dot(at Here)
  line up vsp*.75
  R1: resistor(right_ vsp*2.5); llabel(,R_1,)
  line down to (Here.x,R3.end.y)
  dot(at Here)
} 
VS: source(right_ to 1/2 between Here and (R1.end.x,Here.y),V,,R); llabel(,v_s,)
{
  VB: dot(at Here)
  R4: resistor(down_ to (Here.x,O.y)); rlabel(,R_4,)
  VC: dot(at Here)
}
R2: resistor(right_ to (R1.end.x,Here.y)); llabel(,R_2,)
{
  line right hsp/4
  ground(at Here)
}
IS: source(down_ to (Here.x,O.y),I,,R); rlabel(,i_s,)
line to O

"$v_a$" at VA.w rjust
"$v_b$" at VB.n above
"$v_c$" at VC.s below

IA: arcd(1/2 between R3.end and R1.end,hsp/4,-145,-45) cw ->
IB: arcd(1/2 between R3.end and R4.end,hsp/4,-145,-45) cw ->
IC: arcd(1/2 between R2.start and IS.end,hsp/4,-145,-45) cw ->

"$i_a$" at IA
"$i_b$" at IB
"$i_c$" at IC


.PE