# Issue with DynamicPolynomials and BigFloat coefficients?
**URL:** https://discourse.julialang.org/t/issue-with-dynamicpolynomials-and-bigfloat-coefficients/120814
**Category:** General Usage
**Tags:** polynomials, bigfloat
**Created:** [October 2, 2024, 2:03pm UTC](https://discourse.julialang.org/t/issue-with-dynamicpolynomials-and-bigfloat-coefficients/120814 "2024-10-02T14:03:34Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@chkat](https://discourse.julialang.org/u/chkat)
#### Post date: [October 2, 2024, 2:03pm UTC](https://discourse.julialang.org/t/issue-with-dynamicpolynomials-and-bigfloat-coefficients/120814/1 "2024-10-02T14:03:34Z")
I am experiencing an issue with the latest version of DynamicPolynomials (0.6) when I evaluate a polynomial with BigFloat coefficients at another BigFloat. I isolated a simple example that shows that I get different results if I set the variable `c` to `Float64(0)` or `BigFloat(0)`.
```julia
julia> using DynamicPolynomials
julia> @polyvar a b c
(a, b, c)
julia> F = BigFloat(5)*a*b*c + BigFloat(1)*a*b^2
5.0abc + ab²
julia> DynamicPolynomials.subs(F, c=>BigFloat(0))
0.0
julia> DynamicPolynomials.subs(F, c=>0)
ab²
```
On the contrary, for the version 0.4.6 of the package I get in both cases `ab²` as a result.
\*I tried as well with the same polynomial and coefficient types Float64, and I get the same results
Does anyone know what is the reason please ? Are BigFloats not compatible with DynamicPolynomials ?
---
### Author:  [@nsajko](https://discourse.julialang.org/u/nsajko)
#### Post date: [October 2, 2024, 2:07pm UTC](https://discourse.julialang.org/t/issue-with-dynamicpolynomials-and-bigfloat-coefficients/120814/2 "2024-10-02T14:07:12Z")
Report a bug.
---
### Author:  [@nsajko](https://discourse.julialang.org/u/nsajko)
#### Post date: [October 3, 2024, 10:05am UTC](https://discourse.julialang.org/t/issue-with-dynamicpolynomials-and-bigfloat-coefficients/120814/3 "2024-10-03T10:05:56Z")
@chkat reported a bug, whereupon a fix was promptly pushed.
>
>
> Hi,
> I am experiencing an issue with the latest version when I evaluate a polyn…omial with BigFloat coefficients at another BigFloat. I isolated a simple example that shows that I get different results if I set the variable \`c\` to \`Float64(0)\` or \`BigFloat(0)\`.
>
> \`\`\`julia
> julia\> using DynamicPolynomials
>
> julia\> @polyvar a b c
> (a, b, c)
>
> julia\> F = BigFloat(5)\*a\*b\*c + BigFloat(1)\*a\*b^2
> 5.0abc + ab²
>
> julia\> DynamicPolynomials.subs(F, c=\>BigFloat(0))
> 0.0
>
> julia\> DynamicPolynomials.subs(F, c=\>0.0)
> ab²
> \`\`\`
>
> On the contrary, for the version 0.4.6 of the package I get in both cases \`\`ab²\`\` as a result.
> Are operations with BigFloats not supported ?
>
> Thanks !