Calculate the spectral SNR.

SNR is defined as the maximum signal value divided by the standard deviation of the noise.

calc_spec_snr(
  mrs_data,
  sig_region = c(4, 0.5),
  noise_region = c(-0.5, -2.5),
  p_order = 2,
  interp_f = 4,
  full_output = FALSE
)

Arguments

mrs_data

an object of class mrs_data.

sig_region

a ppm region to define where the maximum signal value should be estimated.

noise_region

a ppm region to defined where the noise level should be estimated.

p_order

polynomial order to fit to the noise region before estimating the standard deviation.

interp_f

interpolation factor to improve detection of the highest signal value.

full_output

output signal, noise and SNR values separately.

Value

an array of SNR values.

Details

The mean noise value is subtracted from the maximum signal value to reduce DC offset bias. A polynomial detrending fit (second order by default) is applied to the noise region before the noise standard deviation is estimated.