# Displaying Frequency Information from Transforms

The discrete implementation of the Fourier transform maps a digital signal into its Fourier series coefficients, or harmonics. Unfortunately, neither a time nor a frequency stamp is directly associated with the FFT operation. Therefore, you must specify the sampling interval Δ*t*.

Because an acquired array of samples represents a progression of equally spaced samples in time, you can determine the corresponding frequency in hertz. The following equation gives the sampling frequency *f*_{s} for Δ*t*.

f_{s} = 1/Δt |
(A) |

The following block diagram belongs to a VI that properly displays frequency information given the sampling interval 1.000E – 3 and returns the value for the frequency interval Δ*f*.

The following front panel shows the display and Δ*f* that the VI with the previous block diagram returns.

Two other common ways of presenting frequency information are displaying the DC component in the center and displaying one-sided spectrums.