Relax conditions for Var.arecompatible

Author: ph-kev

NEWS.md

@@ -60,6 +60,11 @@ sim_var = shift_to_start_of_previous_month(sim_var)
   `net_toa_flux`). ([#109](https://github.com/CliMA/ClimaAnalysis.jl/pull/109
   "PR109"))
 
+## Minor changes
+
+- Var.arecompatible only check for the units of the dimensions instead of checking that the
+  dimension attributes fully match.
+
 v0.5.9
 ------
 

src/Var.jl

@@ -840,7 +840,17 @@ We assume that:
 We also *do not* check units for `data`.
 """
 function arecompatible(x::OutputVar, y::OutputVar)
-    return (x.dims == y.dims) && (x.dim_attributes == y.dim_attributes)
+    x_dims = collect(keys(x.dims))
+    y_dims = collect(keys(y.dims))
+    x_units = (dim_units(x, dim_name) for dim_name in x_dims)
+    y_units = (dim_units(y, dim_name) for dim_name in y_dims)
+
+    for (x_dim, x_unit, y_dim, y_unit) in zip(x_dims, x_units, y_dims, y_units)
+        x_unit == "" && @warn "Missing units for dimension $x_dim in x"
+        y_unit == "" && @warn "Missing units for dimension $y_dim in y"
+        x_unit != y_unit && return false
+    end
+    return x.dims == y.dims
 end
 
 """

test/test_Var.jl

@@ -170,15 +170,15 @@ end
 
     dims = OrderedDict(["time" => time, "lon" => long, "lat" => lat])
     dim_attributes = OrderedDict([
-        "time" => Dict(),
+        "time" => Dict("units" => "s"),
         "lon" => Dict("b" => 2),
         "lat" => Dict("a" => 1),
     ])
     attribs = Dict("short_name" => "bob", "long_name" => "hi")
     var1 = ClimaAnalysis.OutputVar(attribs, dims, dim_attributes, data1)
 
     dim_attributes2 = OrderedDict([
-        "time" => Dict(),
+        "time" => Dict("units" => "m"),
         "lon" => Dict("lol" => 2),
         "lat" => Dict("a" => 1),
     ])