diff --git a/DESCRIPTION b/DESCRIPTION
index 96de1127ca71c5e32243988f5df8d8a2f66b3c32..722009686afb072bbf7aae91e6f632561776d13a 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -9,7 +9,7 @@ Maintainer: Michel Crucifix <michel.crucifix@uclouvain.be>
 Description: Collection of time series analysis tools, focused on spectral decomposition and reconstruction, with an original focus on astronomical theory of paleoclimates and cyclostratigraphy. 
 License: MIT licence
 LazyLoad: yes
-RoxygenNote: 7.3.1
+RoxygenNote: 7.3.2
 Imports: Rdpack, sfsmisc, cmna, gsignal, pracma
 RdMacros: Rdpack
 Depends: 
diff --git a/NAMESPACE b/NAMESPACE
index f3a35dc79b9e1959b74ef6c408ea6c281f3bd878..0cc0f694ae1d59ca7c6c5fd8e90ea52bf6227cab 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -5,6 +5,7 @@ S3method(lines,mfft_deco)
 S3method(plot,SSAObject)
 S3method(plot,memObject)
 S3method(plot,mfft_deco)
+S3method(plot,periodogram)
 S3method(plot,wavelet)
 S3method(print,mfft_deco)
 export(approx_ts)
@@ -16,7 +17,8 @@ export(mfft)
 export(mfft_anova)
 export(mfft_real)
 export(mfft_real_C)
-export(mfft_real_ter)
+export(mfft_real_quatro)
+export(periodogram)
 export(powerspectrum.wavelet)
 export(reconstruct_mfft)
 export(reconstruct_morlet)
diff --git a/R/mfft_real_ter.R b/R/mfft_real_quatro.R
similarity index 99%
rename from R/mfft_real_ter.R
rename to R/mfft_real_quatro.R
index 3ad3e3f22ee07b18f724abcae72554d51359adfa..1d19108d11b7f57c472bbf0d679a6031c34c0edb 100644
--- a/R/mfft_real_ter.R
+++ b/R/mfft_real_quatro.R
@@ -272,9 +272,9 @@ analyse <- function(xdata, nfreq, fast = TRUE, nu = NULL){
 #' OUT <- mfft_real(x_orig)
 #' print(OUT)
 #'
-#' @export mfft_real_ter
+#' @export mfft_real_quatro
   # will withold the definitive frequencies
-mfft_real_ter <- function(xdata, nfreq=5, correction=1, fast=TRUE){
+mfft_real_quatro <- function(xdata, nfreq=5, correction=1, fast=TRUE){
     N <- length(xdata)
     N2 <- N/2.
     xdata = stats::as.ts(xdata)
diff --git a/man/mfft_deco.Rd b/man/mfft_deco.Rd
index 5854949ff44922fc9bc13f3866903c03e989dce2..a42683f743a457ae2fead3d1a86ad357b7e3d2c1 100644
--- a/man/mfft_deco.Rd
+++ b/man/mfft_deco.Rd
@@ -15,7 +15,7 @@ mfft_anova(M)
 
 \method{as.data.frame}{mfft_deco}(x)
 
-\method{plot}{mfft_deco}(M, ...)
+\method{plot}{mfft_deco}(M, periods = FALSE, ...)
 
 \method{lines}{mfft_deco}(M, ...)
 
diff --git a/man/mfft_real_ter.Rd b/man/mfft_real_quatro.Rd
similarity index 68%
rename from man/mfft_real_ter.Rd
rename to man/mfft_real_quatro.Rd
index 862a8b9abc5b909c40c390e6ad35f4199d9ddfcf..1f130018f7b7748e61af5cf59eb633e0bb6e3712 100644
--- a/man/mfft_real_ter.Rd
+++ b/man/mfft_real_quatro.Rd
@@ -1,15 +1,19 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/mfft_real_ter.R
-\name{mfft_real_ter}
-\alias{mfft_real_ter}
+% Please edit documentation in R/mfft_real_quatro.R
+\name{mfft_real_quatro}
+\alias{mfft_real_quatro}
 \title{Modified Fourier transform  for real series (variant)}
 \usage{
-mfft_real_ter(xdata, nfreq = 5, correction = TRUE)
+mfft_real_quatro(xdata, nfreq = 5, correction = 1, fast = TRUE)
 }
 \arguments{
 \item{xdata}{The data provided either as a time series (advised), or as a vector.}
 
 \item{nfreq}{is the number of frequencies returned, must be smaller that the length of  xdata.}
+
+\item{fast}{(default = TRUE) uses analytical formulations for the crossproducts involving sines and cosines}
+
+\item{correction:}{0: no frequency correction (equivalent to Laskar); 1 : frequency correction using linear approximation ; 2: frequency correction using sythetic data}
 }
 \description{
 R-coded version of the Modified Fourier Transform
diff --git a/man/periodogram.Rd b/man/periodogram.Rd
new file mode 100644
index 0000000000000000000000000000000000000000..074e7e6a8256bb579dbee5ad127b1d0744ff6bb3
--- /dev/null
+++ b/man/periodogram.Rd
@@ -0,0 +1,20 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/periodogram.R
+\name{periodogram}
+\alias{periodogram}
+\alias{plot.periodogram}
+\title{Periodogram}
+\usage{
+periodogram(xdata)
+
+\method{plot}{periodogram}(X, ...)
+}
+\arguments{
+\item{xdata}{}
+}
+\description{
+Simple periodogram
+}
+\author{
+Michel Crucifix for the R code
+}