R2 approximation error as in Excel

Hello! In Excel, when building a trend line, it is possible to show an error of R2 approximation, and can this be done in a matlab environment?

my data egg = [20 25 22 24 ...] milk = [102,152 134,141 ...]

Animalfivefive_fit = polyval(egg,milk);

tried to build a trend line, but all values ​​are 'inf'

My task is to do everything as in Excel, but only in the matab

Answer 1

[Torsten]

https://de.mathworks.com/help/stats/coefficient-of-determination-r-squared.html