Merge pull request #161 from r-spatialecology/master

v1.4.1
r-spatialecology · Jan 12, 2020 · a218801 · a218801
2 parents fa9f455 + 904d448
commit a218801
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diff --git a/DESCRIPTION b/DESCRIPTION
@@ -1,7 +1,7 @@
 Type: Package
 Package: landscapemetrics
 Title: Landscape Metrics for Categorical Map Patterns
-Version: 1.4
+Version: 1.4.1
 Authors@R: c(person("Maximillian H.K.", "Hesselbarth",
              role = c("aut", "cre"),
              email = "[email protected]",

diff --git a/NEWS.md b/NEWS.md
@@ -1,7 +1,11 @@
 # landscapemetrics 1.4
-* Improvements
-    * Improved connected-component labelling algorithm. **ATTENTION: THIS LEADS TO DIFFERENT PATCH IDS COMPARED TO PREVIOUS VERSIONS.** 
+* Bugfixes
+    * Bug in the connected-component labelling algorithm for non-rectangular landscapes
 
+# landscapemetrics 1.4
+* Improvements
+    * Improved connected-component labelling algorithm. **Note: The algorithm labels the patches in a different order and therefore may use different patch IDs compared to previous versions.** 
+
 # landscapemetrics 1.3.2
 * Bugfixes
     * Make sure all CRAN checks run

diff --git a/README.Rmd b/README.Rmd
@@ -56,9 +56,10 @@ devtools::install_github("r-spatialecology/landscapemetrics")
 ```
 
 #### Announcement
-
 Due to an improved connected-component labelling algorithm, the patch ID differs between **landscapemetrics** v1.4 and older versions. However, results for all metrics are identical.
 
+The algorithm labels the patches in a different order and therefore may use different patch IDs compared to previous versions.
+
 ## Using landscapemetrics
 
 The resolution of a raster cell has to be in **meters**, as the package converts units internally and returns results in either meters, square meters or hectares. Before using **landscapemetrics**, be sure to check your raster (see `check_raster()`).

diff --git a/README.md b/README.md
@@ -63,6 +63,9 @@ Due to an improved connected-component labelling algorithm, the patch ID
 differs between **landscapemetrics** v1.4 and older versions. However,
 results for all metrics are identical.
 
+The algorithm labels the patches in a different order and therefore may
+use different patch IDs compared to previous versions.
+
 ## Using landscapemetrics
 
 The resolution of a raster cell has to be in **meters**, as the package

diff --git a/cran-comments.md b/cran-comments.md
@@ -1,3 +1,6 @@
+# landscapemetrics 1.4.1
+Major bugfixes
+
 # landscapemetrics 1.4
 Improvments of existing functions and make sure all CRAN checks run
 

diff --git a/src/rcpp_cclabel.cpp b/src/rcpp_cclabel.cpp
@@ -28,27 +28,26 @@ void rcpp_ccl(IntegerMatrix mat, int directions)
     const unsigned nNeig = neigCoordinates.size();
 
     // it's convinient to have patch cells marked as 0 (i.e. un-labeled) and matrix cells as NA
-    for (int row = 0; row < nrows; row++) {
-        for (int col = 0; col < ncols; col++) {
-            if (mat[row * ncols + col] == NA) {
+    for (int col = 0; col < ncols; col++) {
+        for (int row = 0; row < nrows; row++) {
+            if (mat[col * nrows + row] == NA) {
                 continue;
             }
-            mat[row * ncols + col] = 0;
+            mat[col * nrows + row] = 0;
         }
     }
 
     int label = 0;
-    for (int row = 0; row < nrows; row++) {
-        for (int col = 0; col < ncols; col++) {
-
+    for (int col = 0; col < ncols; col++) {
+        for (int row = 0; row < nrows; row++) {
             // ignore background cells and cells that are already labeled
-            if (mat[row * ncols + col] == NA ||
-                    mat[row * ncols + col] > 0) {
+            if (mat[col * nrows + row] == NA ||
+                    mat[col * nrows + row] > 0) {
                 continue;
             }
 
             // label the first cell of the patch
-            mat[row * ncols + col] = ++label;
+            mat[col * nrows + row] = ++label;
 
             std::queue<std::array<const int, 2> > patchcells;
             patchcells.push(std::array<const int, 2>{col, row});
@@ -73,12 +72,12 @@ void rcpp_ccl(IntegerMatrix mat, int directions)
                         continue;
 
                     // skip if background or already labeled
-                    if (mat[row_neig * ncols + col_neig] == NA ||
-                            mat[row_neig * ncols + col_neig] > 0)
+                    if (mat[col_neig * nrows + row_neig] == NA ||
+                            mat[col_neig * nrows + row_neig] > 0)
                         continue;
 
                     // label cell and put in queue
-                    mat[row_neig * ncols + col_neig] = label;
+                    mat[col_neig * nrows + row_neig] = label;
                     patchcells.push(std::array<const int, 2>{col_neig, row_neig});
                 }
             }

diff --git a/tests/testthat/test-rcpp_ccl.R b/tests/testthat/test-rcpp_ccl.R
@@ -0,0 +1,12 @@
+context("rcpp_ccl")
+
+mat8 <- matrix(c(NA, 1L, NA, NA, 1L, 1L, 1L, NA), 4, 2)
+mat4 <- matrix(c(NA, 1L, NA, NA, 1L, 1L, 1L, NA), 4, 2)
+
+landscapemetrics:::rcpp_ccl(mat4, 4)
+landscapemetrics:::rcpp_ccl(mat8, 8)
+
+test_that("rcpp_ccl patch labelling is correct", {
+    expect_equal(length(unlist(get_unique_values(mat4))), 1)
+    expect_equal(length(unlist(get_unique_values(mat8))), 1)
+})