R Notebook

1. Undifference

vec1 <- c(5,7,9,10, 12, 13, 15, 20)
vec2 <- diff(vec1)
vec2

[1] 2 2 1 2 1 2 5

# вернуить в vec1 из vec2: vec3==vec1
vec3 <- diffinv(vec2, xi = vec1[1]) # vec1[1] = 5
# Нам надо запонить vec[1]
# результат
vec3

[1]  5  7  9 10 12 13 15 20

2. Unlog

vec1 <- c(5,7,9,10, 12, 13, 15, 20)
vec2 <- log(vec1)
vec2

[1] 1.609438 1.945910 2.197225 2.302585 2.484907 2.564949 2.708050 2.995732

# unlog
vec3 <- exp(vec2)
vec3

[1]  5  7  9 10 12 13 15 20

3. Из 1-2 => un_log of diff

vec1 <- c(5,7,9,10, 12, 13, 15, 20)
vec2 <- log(diff(vec1))
vec2

[1] 0.6931472 0.6931472 0.0000000 0.6931472 0.0000000 0.6931472 1.6094379

# вернуть в vec1 из vec2
vec3 <- diffinv(exp(vec2), xi = 5)
vec3

[1]  5  7  9 10 12 13 15 20