gftrunc

Minimize length of polynomial representation

Description

example

c = gftrunc(a) truncates a row vector, a, that gives the coefficients of a GF(p) polynomial in order of ascending powers. If a(k) = 0 whenever k > d + 1, the polynomial has degree d. The row vector c omits these high-order zeros and thus has length d + 1.

Examples

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Use gftrunc to truncate the row-vector representation of ${\mathit{x}}^{2}+{2\mathit{x}}^{3}+{3\mathit{x}}^{4}+{4\mathit{x}}^{7}+{5\mathit{x}}^{8}$, removing nonsignificant zero-valued elements.

vec = [0 0 1 2 3 0 0 4 5 0 0]
vec = 1×11

0     0     1     2     3     0     0     4     5     0     0

gfpretty([vec])

2      3      4      7      8
X  + 2 X  + 3 X  + 4 X  + 5 X

Zeros are removed from the end of the row-vector representation, but not from the beginning or middle of the row vector.

c = gftrunc([0 0 1 2 3 0 0 4 5 0 0])
c = 1×9

0     0     1     2     3     0     0     4     5

gfpretty(c)

2      3      4      7      8
X  + 2 X  + 3 X  + 4 X  + 5 X