doc/spice3.txt

   1
   2 Notes on the "rawfile" format generated by Berkeley spice3 and ng-spice.
   3 Sadly, neither program documents the file format.
   4
   5 Top of an example file:
   6
   7 Title: * RC circuit driven by square wave
   8 Date: Sun Oct  8 22:29:16  2000
   9 Plotname: Transient Analysis
  10 Flags: real
  11 No. Variables: 6
  12 No. Points: 85
  13 Command: version 12
  14 Variables:
  15         0       time    time
  16         1       gnd     voltage
  17         2       a       voltage
  18         3       b       voltage
  19         4       va#branch       current
  20         5       vgnd#branch     current
  21 Values:
  22 0               0.000000000000000e+00
  23         0.000000000000000e+00
  24         0.000000000000000e+00
  25         0.000000000000000e+00
  26         0.000000000000000e+00
  27         0.000000000000000e+00
  28 1               5.000000000000002e-12
  29         0.000000000000000e+00
  30         0.000000000000000e+00
  31         0.000000000000000e+00
  32         0.000000000000000e+00
  33         0.000000000000000e+00
  34
  35
  36
  37 The header consists of lines with "name: value" parameter assignments.
  38
  39 Following a Variables: line, are "No. Variables" lines each containing
  40 an index, name, and variable-type.
  41
  42 Following a "Values:" line is the data.
  43 Each chunk of data represents a row, and contains "No. Variables" lines.
  44 The first line of a chunk starts with an index or point number.
  45 Indexes run 0 through "No. points" minus one.
  46
  47
  48 If "Flags: complex" instead of "Flags: real", the each data point
  49 is a complex pair seperated by a comma:
  50
  51 0               1.000000000000000e+00,7.227131787662363e-270
  52         0.000000000000000e+00,0.000000000000000e+00
  53         0.000000000000000e+00,0.000000000000000e+00
  54         1.000000000000000e+00,0.000000000000000e+00
  55         8.638022681143612e-01,-9.279561053152983e-08
  56
  57
  58 Assumed to be "real,imaginary" but not confirmed.
  59 "Complex" is an all-or-nothing situation.
  60
  61 Instead of a "Variables:" section there may be a "Binary:" section.
  62 In this case, the data appears to be 64-bit double-precion floating point,
  63 with "No. variables" * "No. points" doubles, following immediately after
  64 the newline in "Binary:\n"
  65
  66 To get spice3 or ngspice to generate an ascii rawfile instead of binary,
  67 set the environment variable SPICE_ASCIIRAWFILE
  68
  69
  70 Some analysis types have no independent variable.
  71 One is pole-zero analysis; its output consists only of
  72 the complex values of the poles:
  73
  74 Title: spice file generated by ...
  75 Date: Tue Oct 27 21:50:41  2009
  76 Plotname: Pole-Zero Analysis
  77 Flags: complex
  78 No. Variables: 2
  79 No. Points: 1
  80 Variables:
  81         0       v(pole(1))      voltage
  82         1       v(pole(2))      voltage
  83 Values:
  84 0               -2.221441543562163e+05,2.221441281761691e+05
  85         -2.221441543562163e+05,-2.221441281761691e+05
  86
  87 (Binary version has exactly 32 bytes of output - 4 doubles.)
  88