From 16c48d9cacccad78e040258ceff9634b1d79f88f Mon Sep 17 00:00:00 2001
From: PharmCat <v.s.arnautov@yandex.ru>
Date: Sun, 8 Aug 2021 13:40:22 +0300
Subject: [PATCH] statutils

---
 Project.toml |  2 +-
 src/types.jl |  2 +-
 src/utils.jl | 39 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/Project.toml b/Project.toml
index db4d3d1..ae2a57d 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "MetidaBase"
 uuid = "075456b7-4006-432f-9324-2f8453996c49"
 authors = ["PharmCat <v.s.arnautov@yandex.ru> and contributors"]
-version = "0.3.1"
+version = "0.3.2"
 
 [deps]
 #StatsBase = "2913bbd2-ae8a-5f71-8c99-4fb6c76f3a91"
diff --git a/src/types.jl b/src/types.jl
index c28748d..0ab1087 100644
--- a/src/types.jl
+++ b/src/types.jl
@@ -220,7 +220,7 @@ end
 function subset(d::DataSet, sort::Dict)
     inds = findall(x-> sort ⊆ x.id, d.ds)
     if length(inds) > 0 return DataSet(d.ds[inds]) end
-    nothing
+    []
 end
 ################################################################################
 # metida_table from DataSet{AbstractIDResult}
diff --git a/src/utils.jl b/src/utils.jl
index 504397c..b5eb963 100644
--- a/src/utils.jl
+++ b/src/utils.jl
@@ -19,3 +19,42 @@ end
 
 isnanormissing(x::Number) = isnan(x)
 isnanormissing(x::Missing) = true
+
+
+# STATISTICS
+
+
+#CV2se
+"""
+    sdfromcv(cv::Real)::AbstractFloat
+
+LnSD from CV.
+"""
+function sdfromcv(cv)
+    return sqrt(varfromcv(cv))
+end
+"""
+    varfromcv(cv::Real)::AbstractFloat
+
+LnVariance from CV.
+"""
+function varfromcv(cv)
+     return log(1+cv^2)
+end
+"""
+    cvfromvar(σ²::Real)::AbstractFloat
+
+CV from variance.
+"""
+function cvfromvar(σ²)
+    return sqrt(exp(σ²)-1)
+end
+#CV2se
+"""
+    cvfromsd(σ::Real)::AbstractFloat
+
+CV from variance.
+"""
+function cvfromsd(σ)
+    return sqrt(exp(σ^2)-1)
+end