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Scilab Help >> Polynomials > varn

# varn

symbolic variable of a polynomial or a rational

### Calling Sequence

```[symb]=varn(p)
[pm]=varn(p,varname)```

### Arguments

p

matrix of polynomials or of rationals

symb

character string: name of the variable

varname

character string: the new name of the variable of `p`, set for `pm`

pm

matrix of polynomials or of rationals

### Description

`symb=varn(p)` returns in `symb` the symbolic variable of the polynomial `p` (i.e. `varn(poly(0,'x'))` is `'x'`).

`varn(p,'s')` returns a polynomial matrix with same coefficients as `p` but with `'s'` as symbolic variable (change of variable name).

### Examples

```s = poly(0,'s'); p = [s^2+1,s];
varn(p)
varn(p,'x')

f = %z / (%z-1); f = [f f^2]
varn(f)
varn(f,"x")```

• poly — polynomial definition
• rlist — Scilab rational fraction function definition
• horner — polynomial/rational evaluation

### History

 Version Description 5.5.1 Extension to rationals