# Documentation

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# sym2poly

Extract vector of all numeric coefficients, including zeros, from symbolic polynomial

## Syntax

``c = sym2poly(p)``

## Description

example

````c = sym2poly(p)` returns the numeric vector of coefficients `c` of the symbolic polynomial `p`. The returned vector `c` includes all coefficients, including those equal `0`.`sym2poly` returns coefficients in order of descending powers of the polynomial variable. If ${c}_{1}{x}^{n-1}+{c}_{2}{x}^{n-2}+...+{c}_{n}$, then `c = sym2poly(p)` returns ```c = [c1 c2 ... cn]```.```

## Examples

### Extract Numeric Coefficients of Polynomial

Create row vectors of coefficients of symbolic polynomials.

Extract integer coefficients of a symbolic polynomial into a numeric row vector.

```syms x c = sym2poly(x^3 - 2*x - 5)```
```c = 1 0 -2 -5```

Extract rational and integer coefficients of a symbolic polynomial into a vector. Because `sym2poly` returns numeric double-precision results, it approximates exact rational coefficients with double-precision numbers.

`c = sym2poly(1/2*x^3 - 2/3*x - 5)`
```c = 0.5000 0 -0.6667 -5.0000```

## Input Arguments

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Polynomial, specified as a symbolic expression.

## Output Arguments

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Polynomial coefficients, returned as a numeric row vector.

## Tips

• To extract symbolic coefficients of a polynomial, use `coeffs`. This function returns a symbolic vector of coefficients and omits all zeros. For example, `syms a b x; c = coeffs(a*x^3 - 5*b,x)` returns ```c = [ -5*b, a]```.