♻️ Refactor unit test to be non-square (#6)

* 🐛 Fix array dimension order to be y (height), x (width)

Classic mistake of getting the wrong order when mixing geographic xy with image yx. Corrected to use y (height), x (width) order, and updated unit test to be non-square so that this won't happen again.

* ⏪ Dimensions in TIFF decoder and writer is actually width height

Getting confused with the `tiff` crate using (width, height), while `ndarray` uses (height, width)...

* 🍻 More height and width swapping

Need to get my head straight on these ordering issues...

src/io/geotiff.rs

@@ -38,9 +38,9 @@ mod tests {
     fn test_read_geotiff() {
         // Generate some data
         let mut image_data = Vec::new();
-        for x in 0..20 {
-            for y in 0..20 {
-                let val = x + y;
+        for y in 0..10 {
+            for x in 0..20 {
+                let val = y + x;
                 image_data.push(val as f32);
             }
         }
@@ -49,13 +49,16 @@ mod tests {
         let mut file = tempfile().unwrap();
         let mut bigtiff = TiffEncoder::new_big(&mut file).unwrap();
         bigtiff
-            .write_image::<colortype::Gray32Float>(20, 20, &image_data)
+            .write_image::<colortype::Gray32Float>(20, 10, &image_data) // width, height, data
             .unwrap();
         file.seek(SeekFrom::Start(0)).unwrap();
 
         // Read a BigTIFF file
         let arr = read_geotiff(file).unwrap();
-        assert_eq!(arr.dim(), (20, 20));
-        assert_eq!(arr.mean(), Some(19.0));
+        assert_eq!(arr.ndim(), 2);
+        assert_eq!(arr.dim(), (10, 20)); // (height, width)
+        assert_eq!(arr.nrows(), 10); // y-axis
+        assert_eq!(arr.ncols(), 20); // x-axis
+        assert_eq!(arr.mean(), Some(14.0));
     }
 }