An SVF stream contains two types of records, a size record and an element record. The size record contains the length of the vector and the element record contains the index and value for one element. The stream can contain multiple input vectors where each vector is defined by a size record followed by its element records. The size record is optional for the first vector.

A size record has one white-space delimited integer field. The field holds the number of elements in the vector. The size record if present must precede the element records for a vector.

An element record has three white-space delimited fields. The first is integer and holds index. The second field  holds the real part of the element. The third field is optional and hold the imaginary part of the element.

A any line with a leading '#' is taken as a comment and ignored.

Here is an example SVF input stream:

# -------------------------------
# The first vector - dense 4
# -------------------------------
4
0  2.3
1  4.5  3.6
2  5.8
3  0.0  4.3

# --------------------------------------
# The second vector - sparse 100
# --------------------------------------
100
  0  34.6  0.5
55  49.0  3.1
99  32.4
18  32.8