# polfact

### 呼び出し手順

`f = polfact(p)`

### パラメータ

p

f

row vector `[f0 f1 ... fn]` of polynomials with real coefficients, such that `p=prod(f)`. `f0=f(1)` is a constant polynomial. `f(2:\$)` are polynomials of degree 1 or 2.

 The coefficients of `f` polynomials are computed with a relative uncertainty of `%eps`1/degree(p).

### 例

```x = poly(0,"x");
%eps^[1/3 1/7]

p = (1-x)^3
f = polfact(p)'
prod(f)

p = (1+x)^7
f = polfact(p)'
prod(f)```
```--> %eps^[1/3 1/7]
ans  =
0.0000061   0.0058047

--> p = (1-x)^3
p  =
1 -3x +3x² -x³

--> f = polfact(p)'
f  =
-1
1.0000086 -2.0000086x +x²
-0.9999914 +x

--> prod(f)
ans  =
1 -3x +3x² -x³

--> p = (1+x)^7
p  =
1 +7x +21x² +35x³ +35x⁴ +21x⁵ +7x⁶ +x⁷

--> f = polfact(p)'
f  =
1
1.0092002 +x
1.0114552 +2.011371x +x²
0.9959088 +1.9958255x +x²
0.9836859 +1.9836034x +x²

--> prod(f)
ans  =
1 +7x +21x² +35x³ +35x⁴ +21x⁵ +7x⁶ +x⁷
```

### 参照

• factors — 実数因数分解
• roots — 多項式の根
• lcm — least common (positive) multiple of integers or of polynomials
• cmndred — 共通分母形式
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