Calculate sample-number-based weights in make.cube

CITATION.cff

@@ -33,5 +33,5 @@ keywords:
   - spectroscopy
   - submillimeter
 license: MIT
-version: 2025.8.0
+version: 2025.10.0
 date-released: '2025-08-18'

README.md

@@ -11,7 +11,7 @@ DESHIMA code for data analysis
 ## Installation
 
 ```shell
-pip install decode==2025.8.0
+pip install decode==2025.10.0
 ```
 
 ## Quick look

decode/__init__.py

@@ -11,7 +11,7 @@
     "stats",
     "utils",
 ]
-__version__ = "2025.8.0"
+__version__ = "2025.10.0"
 
 
 # submodules

decode/make.py

@@ -33,7 +33,8 @@ def cube(
         skycoord_units: Units of the sky coordinate axes.
 
     Returns:
-        Cube DataArray.
+        Cube DataArray. The weight coordinate is the inverse
+        variance of the input DEMS samples within each pixel.
 
     """
     dems = convert.coord_units(dems, "lon", "deg")
@@ -56,14 +57,20 @@ def cube(
 
     dems = dems.copy(data=dems.data)
     dems.coords.update({"index": index})
-    gridded = dems.groupby("index").mean("time")
+    mean = dems.groupby("index").mean("time")
+    var = dems.groupby("index").var("time")
 
     data = np.full([n_lat * n_lon, n_chan], np.nan)
-    data[gridded.index.values] = gridded.values
+    data[mean.index.values] = mean.values
     data = data.reshape(n_lat, n_lon, n_chan).transpose(2, 0, 1)
 
+    weight = np.full([n_lat * n_lon, n_chan], np.nan)
+    weight[var.index.values] = 1 / var.values
+    weight = weight.reshape(n_lat, n_lon, n_chan).transpose(2, 0, 1)
+
     cube = Cube.new(
         data=data,
+        weight=weight,
         lat=lat,
         lon=lon,
         chan=dems.chan,

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "decode"
-version = "2025.8.0"
+version = "2025.10.0"
 description = "DESHIMA code for data analysis"
 readme = "README.md"
 keywords = [