fix: NA when no sounding data

NAMESPACE

@@ -1,4 +1,5 @@
 # Generated by roxygen2: do not edit by hand
 
+export(download_airport_sounding)
 export(download_senamhi_met)
 export(download_senamhi_pol)

R/download_airport_sounding.R

@@ -1,3 +1,21 @@
+#' Download sounding from Jorge Chavez Airport
+#' Download sounding from Jorge Chavez Airport (SPIM or 84628) from
+#' <https://weather.uwyo.edu/upperair/sounding.html> . It can also download
+#' from any other airport by changing the dafault values.
+#'
+#' @param date Date to download in dd/mm/yyyy.
+#' @param hour 12 or 00. Default is 12
+#' @param airport Airport code. Default is "SPIM" (Jorge Chavez Airport)
+#' @param region Region to download. Default is "samer" (South America)
+#'
+#' @return data.frame with sounding data
+#' @export
+#'
+#' @examples
+#' \dontrun{
+#' # Download sounding from 12z 15/01/2019
+#' jc_sound <- download_airport_sounding("15/01/2019")
+#' }
 download_airport_sounding <- function(date, hour = 12, airport = "SPIM",
                                       region = "samer"){
 
@@ -23,36 +41,42 @@ download_airport_sounding <- function(date, hour = 12, airport = "SPIM",
 
   sound_html <- XML::htmlParse(sounding)
   sound_html_table <- XML::getNodeSet(sound_html, "//pre")
-  sound_data_html <- sound_html_table[[1]]
-  sound_text <- utils::capture.output(sound_data_html)
-  sound_data <- sound_text[6:(length(sound_text)-1)]
-
-  pres <- substr(sound_data, 2, 7)
-  hght <- substr(sound_data, 8, 14)
-  temp <- substr(sound_data, 15, 21)
-  dwpt <- substr(sound_data, 22, 28)
-  relh <- substr(sound_data, 29, 35)
-  mixr <- substr(sound_data, 36, 42)
-  drct <- substr(sound_data, 43, 49)
-  sknt <- substr(sound_data, 50, 56)
-  thta <- substr(sound_data, 57, 63)
-  thte <- substr(sound_data, 64, 70)
-  thtv <- substr(sound_data, 71, 77)
-
-  sound_df <- data.frame(
-    pres = pres,
-    hght = hght,
-    temp = temp,
-    dwpt = dwpt,
-    relh = relh,
-    mixr = mixr,
-    drct = drct,
-    sknt = sknt,
-    thta = thta,
-    thte = thte,
-    thtv = thtv
-  )
-
-  sound_df[, 1:11] <- sapply(sound_df[,1:11], as.numeric)
+
+  if (length(sound_html_table) != 0){
+    sound_data_html <- sound_html_table[[1]]
+    sound_text <- utils::capture.output(sound_data_html)
+    sound_data <- sound_text[6:(length(sound_text)-1)]
+
+    pres <- substr(sound_data, 2, 7)
+    hght <- substr(sound_data, 8, 14)
+    temp <- substr(sound_data, 15, 21)
+    dwpt <- substr(sound_data, 22, 28)
+    relh <- substr(sound_data, 29, 35)
+    mixr <- substr(sound_data, 36, 42)
+    drct <- substr(sound_data, 43, 49)
+    sknt <- substr(sound_data, 50, 56)
+    thta <- substr(sound_data, 57, 63)
+    thte <- substr(sound_data, 64, 70)
+    thtv <- substr(sound_data, 71, 77)
+
+    sound_df <- data.frame(
+      pres = pres,
+      hght = hght,
+      temp = temp,
+      dwpt = dwpt,
+      relh = relh,
+      mixr = mixr,
+      drct = drct,
+      sknt = sknt,
+      thta = thta,
+      thte = thte,
+      thtv = thtv
+    )
+
+    sound_df[, 1:11] <- sapply(sound_df[,1:11], as.numeric)
+  } else {
+    message("No data available. Returning NA")
+    sound_df <- NA
+  }
   return(sound_df)
 }