中的R

Question

I have a data like this and i dont know how to make plot with it, so i wirte a script to change to another form

這裏「長度爲零的參數」是dput的結果（頭（E1））：

structure(list(lon = c(-26.583, -26.25, -26.417, -67.25, -67.25, 
-67.417), lat = c(-59.083, -58.417, -58.417, -55.917, -55.75, 
-55.75), pre1 = c(105.4, 106.3, 106.6, 73.1, 68.7, 70.2)), .Names = c("lon", 
"lat", "pre1"), row.names = c(NA, 6L), class = "data.frame") 

第一列是經度和第二個是緯度，第三個是這一點的降水值。我想要做的是通過這些數據製作地圖，但我不知道如何處理這種格式，所以我想將其更改爲三個矩陣：一個用於經度，一個用於緯度，一個用於降水，還有一個用於降水使用函數image.plot（lon，lat，pre1）製作降水圖。

這是我的腳本：

rerange<-function(e1) { 
latq<-sort(e1$lat,decreasing = T) 
latq<-as.matrix(latq) 
latq1<-unique.matrix(latq) 
lonq<-sort(e1$lon) 
lonq<-as.matrix(lonq) 
lonq1<-unique.matrix(lonq) 
lenlon<-length(lonq1) 
lenlat<-length(latq1) 
finalq<-matrix(0,lenlon,lenlat) 
for (i in 1:lenlat) { 
    for (j in 1:lenlon) { 
     finalq[i,j]<-e1$pre1[e1$lon == lonq1[j] & e1$lat == latq1[i] ] 
    } 
    } 
return(finalq) 
} 

但它返回一個像這樣的錯誤：

Error in finalq[i, j] <- e1$pre1[e1$lon == lonq1[j] & e1$lat == latq1[i]] : 
replacement has length zero 

我有嘗試其他方式，但我無法弄清楚error.How我可以修理它？任何援助將不勝感激。

Answer 1

好了，檢查出你的數據，我覺得這是多還是少，你所追求的：

# create the dataframe 
df <- structure(list(lon = c(-26.583, -26.25, -26.417, -67.25, -67.25, 
        -67.417), lat = c(-59.083, -58.417, -58.417, -55.917, -55.75, 
            -55.75), pre1 = c(105.4, 106.3, 106.6, 73.1, 68.7, 70.2)), .Names = c("lon", 
                              "lat", "pre1"), row.names = c(NA, 6L), class = "data.frame") 

# change from long to wide format 
test <- reshape(df, timevar = "lat", idvar = "lon", direction = "wide") 
# turn missing values into zeros 
test[is.na(test)] <- 0 
# use lon for rownames 
rownames(test) <- test[, 1] 
# drop the first column 
test <- test[,c(2:5)] 
# load stringr library 
library(stringr) 
# drop text from column names 
colnames(test) <- str_replace(colnames(test), "pre1.", "") 
# put rownames and colnames into increasing order 
test <- test[order(rownames(test), decreasing = TRUE), order(colnames(test), decreasing = TRUE)] 
test 
# load the plotting library 
library(fields) 
# make the plot 
image.plot(as.numeric(rownames(test)), as.numeric(colnames(test)), as.matrix(test)) 

這是你需要什麼？