用时间序列 R 中的先前值替换零 [英] Replacing zero with previous value in time series R

问题描述

我有这个时间序列

               Quant1       Quant2
2013-01-23      400         200
2013-01-22        0         0
2013-01-21        0         0
2013-01-20      125         100
2013-01-18      120         0

并希望输出为

               Quant1       Quant2
2013-01-23      400         200
2013-01-22      125         100
2013-01-21      125         100
2013-01-20      125         100
2013-01-18      120         0

我正在尝试这个，但它似乎不起作用.我在处理方法时遇到 null 错误 NULL 警告

I am trying this, but it does not seem to work. I am getting null error NULL Warning encountered while processing method

replace(df,df == 0, NA)    
df <- na.locf(df)
df[is.na(df)] <- 0

有什么建议吗?

更新
根据我尝试过的投票最多的答案(我修改了输入日期)

Update
As per most voted answer I tried (I modified input dates)

> z <- structure(c(400L, 0L, 0L, 125L, 120L, 200L, 0L, 0L, 100L, 
+ 0L), .Dim = c(5L, 2L), .Dimnames = list(NULL, c("Quant1", "Quant2"
+ )), index = structure(c(15728, 15727, 15726, 15725, 15723), class = "Date"), 
+ class = "zoo")
> z
           Quant1 Quant2
2013-01-23    400    200
2013-01-22      0      0
2013-01-21      0      0
2013-01-20    125    100
2013-01-18    120      0
> L <- rowSums(z != 0) > 0
> z[] <- coredata(z)[which(L)[cumsum(L)],]
> z
           Quant1 Quant2
2013-01-23    400    200
2013-01-22      0      0
2013-01-21      0      0
2013-01-20      0      0
2013-01-18    120      0

推荐答案

将来请让您的问题独立，包括库调用和 dput(x) 任何输入 的输出x.

In the future please make your questions self-contained including the library calls and dput(x) output of any input x.

我们假设这是一个动物园对象，如最后所示.我们将其称为 z，因为 df 表明它是一个数据框.

We assume this is a zoo object as shown at the end. We will call it z since df suggests that its a data frame.

library(zoo)

L <- rowSums(z != 0) > 0
z[] <- coredata(z)[which(L)[cumsum(L)],]

给予:

> z
           Quant1 Quant2
2013-01-18    400    200
2013-01-20    400    200
2013-01-21    400    200
2013-01-22    125    100
2013-01-23    120      0

注意:使用了这个输入:

z <- structure(c(400L, 400L, 400L, 125L, 120L, 200L, 200L, 200L, 100L, 
0L), .Dim = c(5L, 2L), .Dimnames = list(NULL, c("Quant1", "Quant2"
)), index = structure(c(15723, 15725, 15726, 15727, 15728), class = "Date"), 
class = "zoo")

这篇关于用时间序列 R 中的先前值替换零的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！