# The new version of SimOne 2.7 is now available

**What’s new in SimOne 2.7**

**SimOne Updater**

The **SimOne** Updater works if the internet connection is active. It provides a fast and easy way to update the SimOne version to the latest published one. When updated the reserve copy of the current version is performed and the user can later roll back to it.

The **Updater** window

is called with the **Check for new version** button at the About SimOne window (**Help → About SimOne…**menu entry).

The **Rollback** to the previous version is made with the corresponding button.

**Math expressions**

New functions for Fourier transform are added

FFT | fft(f(x)[,N=1024,Freq]) – Discrete Fourier transform of expression f(x) with fundamental frequency Freq and N points. Fourier transform is performed over the last period of length 1/Freq. The value Freq can be either given explicitly or calculated automatically. The result of FFT is a vector of complex values. |

FFTN | fftn(f(x)[,N=1024,Freq]) – normalized specter of f(x). It is calculated with FFT function described above and its result is a ratio of FFT and the fundamental harmonic absolute value. |

THD | thd(f(x)[,N=1024,Freq]) – harmonic distortions coefficient of f(x). It is calculated as the ratio of root mean square sum of all harmonics of f(x) but the fundamental and the fundamental harmonic. FFT function is used. |

THD_R | thd_r(f(x)[,N=1024,Freq]) – nonlinear distortions coefficient of f(x). It is calculated as the ratio of root mean square sum of all harmonics of f(x) but the fundamental and root mean square sum of all harmonics. FFT function is used. |

HARM | harm(f(x),Nh=1[,N=1024,Freq]) – Nh-th harmonic of f(x). The result is calculated with FFT and is a complex number. |

FOURIER | fourier(f(x),[Nr=N,N=1024,Freq]) – the sum of Nr terms of Fourier series of f(x).. FFT function is used. |

These functions can be used in expressions to be plotted at graphs, but cannot be used in expressions describing components behavior.

An example of using the Fourier transforms is shown in **fft_based_func.ssch**file contained in FFT folder of SimOne examples. It can be opened with File→Examples… menu entry.

**Fixes**

- Some known issues with subcircuits are fixed.