Merge pull request #453 from adokter/scan_wavelength_attribute

fix issue #298

R/ppi.R

@@ -109,13 +109,13 @@ dim.ppi <- function(x) {
 #' # Project a scan as a ppi
 #' ppi <- project_as_ppi(example_scan)
 #'
-#' # This ppi contains 5 parameters (VRADH DBZH ZDR RHOHV PHIDP)
+#' # This ppi contains 5 parameters (DBZH VRADH ZDR RHOHV PHIDP)
 #' ppi
 #'
-#' # Subset ppi to one containing only the first parameter (VRADH)
+#' # Subset ppi to one containing only the first parameter (DBZH)
 #' ppi[1]
 #'
-#' # Subset ppi to one containing the first three parameters (VRADH, DBZH, ZDR)
+#' # Subset ppi to one containing the first three parameters (DBZH, VRADH, ZDR)
 #' ppi[1:3]
 #'
 #' # Subset ppi to one without the first 2 parameters (ZDR RHOHV PHIDP)

R/read_pvolfile.R

@@ -225,11 +225,17 @@ read_pvolfile_body <- function(file, param = c(
   attribs.where$lat <- vol.lat
   attribs.where$lon <- vol.lon
 
+  # assemble attributes in list
+  attributes <- list(
+    how = attribs.how, what = attribs.what,
+    where = attribs.where
+  )
+
   # read scan groups
   data <- lapply(
     scans,
     function(x) {
-      read_pvolfile_scan(file, x, param, radar, datetime, geo)
+      read_pvolfile_scan(file, x, param, radar, datetime, geo, attributes)
     }
   )
 
@@ -249,10 +255,7 @@ read_pvolfile_body <- function(file, param = c(
   # prepare output
   output <- list(
     radar = radar, datetime = datetime, scans = data,
-    attributes = list(
-      how = attribs.how, what = attribs.what,
-      where = attribs.where
-    ), geo = geo
+    attributes = attributes, geo = geo
   )
   class(output) <- "pvol"
   if (cleanup) {
@@ -261,7 +264,7 @@ read_pvolfile_body <- function(file, param = c(
   output
 }
 
-read_pvolfile_scan <- function(file, scan, param, radar, datetime, geo) {
+read_pvolfile_scan <- function(file, scan, param, radar, datetime, geo, attributes) {
   h5struct <- h5ls(file)
   h5struct <- h5struct[h5struct$group == paste("/", scan, sep = ""), ]$name
   groups <- h5struct[grep("data", h5struct)]
@@ -327,6 +330,9 @@ read_pvolfile_scan <- function(file, scan, param, radar, datetime, geo) {
   quantities <- lapply(quantities, "[[", "quantity")
   names(quantities) <- quantityNames
 
+  # if wavelength is attribute is missing at the scan level, copy it from the pvol level
+  if(is.null(attribs.how$wavelength)) attribs.how$wavelength = attributes$how$wavelength
+
   output <- list(
     radar = radar, datetime = datetime, params = quantities,
     attributes = list(

tests/testthat/test-ppi.R

@@ -29,8 +29,8 @@ test_that("dim.ppi() returns number of params, x, y", {
 })
 
 test_that("[.ppi subsets by param", {
-  # parameters:  VRADH DBZH ZDR RHOHV PHIDP
-  expect_equal(names(ppi[1]$data), c("VRADH"))
-  expect_equal(names(ppi[2:4]$data), c("DBZH", "ZDR", "RHOHV"))
-  expect_equal(names(ppi[-2:-4]$data), c("VRADH", "PHIDP")) # All except 2 to 4
+  # parameters: DBZH VRADH RHOHV ZDR PHIDP
+  expect_equal(names(ppi[1]$data), c("DBZH"))
+  expect_equal(names(ppi[2:4]$data), c("VRADH", "RHOHV", "ZDR"))
+  expect_equal(names(ppi[-2:-4]$data), c("DBZH", "PHIDP")) # All except 2 to 4
 })