Limit JSON print to 10 significant figures

Author: tbody-cfs

cfspopcon/file_io.py

@@ -121,5 +121,16 @@ def write_point_to_file(dataset: xr.Dataset, point_key: str, point_params: dict,
 
     output_dir.mkdir(parents=True, exist_ok=True)
 
+    class RoundingFloat(float):
+        """A formatter to control how floats are written to JSON.
+
+        From: https://stackoverflow.com/questions/54370322/how-to-limit-the-number-of-float-digits-jsonencoder-produces
+        """
+
+        __repr__ = staticmethod(lambda x: f"{x:#.10g}")
+
+    json.encoder.c_make_encoder = None  # type:ignore[attr-defined]
+    json.encoder.float = RoundingFloat  # type:ignore[attr-defined]
+
     with open(output_dir / f"{point_key}.json", "w") as file:
         json.dump(point.to_dict(), file, indent=4, sort_keys=True)

tests/regression_results/AUG_SepOS_minTe.json

@@ -3,12 +3,12 @@
     "coords": {
         "dim_separatrix_electron_density": {
             "attrs": {},
-            "data": 1.443846153846154,
+            "data": 1.443846154,
             "dims": []
         },
         "dim_separatrix_electron_temp": {
             "attrs": {},
-            "data": 57.51724137931035,
+            "data": 57.51724138,
             "dims": []
         }
     },
@@ -17,203 +17,203 @@
             "attrs": {
                 "units": "tesla"
             },
-            "data": 0.3265306124226533,
+            "data": 0.3265306124,
             "dims": []
         },
         "B_t_out_mid": {
             "attrs": {
                 "units": "tesla"
             },
-            "data": 1.927570093457944,
+            "data": 1.927570093,
             "dims": []
         },
         "SepOS_LH_transition": {
             "attrs": {
                 "units": "dimensionless"
             },
-            "data": 1.0025081265471087,
+            "data": 1.002508127,
             "dims": []
         },
         "SepOS_MHD_limit": {
             "attrs": {
                 "units": "dimensionless"
             },
-            "data": 0.3560483425183738,
+            "data": 0.3560483425,
             "dims": []
         },
         "SepOS_density_limit": {
             "attrs": {
                 "units": "dimensionless"
             },
-            "data": 0.5502074424382402,
+            "data": 0.5502074424,
             "dims": []
         },
         "alpha_t": {
             "attrs": {
                 "units": "dimensionless"
             },
-            "data": 0.5195258259822426,
+            "data": 0.5195258260,
             "dims": []
         },
         "areal_elongation": {
             "attrs": {
                 "units": "dimensionless"
             },
-            "data": 1.64,
+            "data": 1.640000000,
             "dims": []
         },
         "critical_alpha_MHD": {
             "attrs": {
                 "units": "dimensionless"
             },
-            "data": 2.5486604604701935,
+            "data": 2.548660460,
             "dims": []
         },
         "cylindrical_safety_factor": {
             "attrs": {
                 "units": "dimensionless"
             },
-            "data": 4.476700876332845,
+            "data": 4.476700876,
             "dims": []
         },
         "elongation_psi95": {
             "attrs": {
                 "units": "dimensionless"
             },
-            "data": 1.6,
+            "data": 1.600000000,
             "dims": []
         },
         "elongation_ratio_areal_to_psi95": {
             "attrs": {
                 "units": "dimensionless"
             },
-            "data": 1.025,
+            "data": 1.025000000,
             "dims": []
         },
         "fraction_of_P_SOL_to_divertor": {
             "attrs": {
                 "units": "dimensionless"
             },
-            "data": 0.6,
+            "data": 0.6000000000,
             "dims": []
         },
         "inverse_aspect_ratio": {
             "attrs": {
                 "units": "dimensionless"
             },
-            "data": 0.296969696969697,
+            "data": 0.2969696970,
             "dims": []
         },
         "ion_heat_diffusivity": {
             "attrs": {
                 "units": "meter ** 2 / second"
             },
-            "data": 0.5,
+            "data": 0.5000000000,
             "dims": []
         },
         "ion_mass": {
             "attrs": {
                 "units": "unified_atomic_mass_unit"
             },
-            "data": 2.0,
+            "data": 2.000000000,
             "dims": []
         },
         "magnetic_field_on_axis": {
             "attrs": {
                 "units": "tesla"
             },
-            "data": 2.5,
+            "data": 2.500000000,
             "dims": []
         },
         "major_radius": {
             "attrs": {
                 "units": "meter"
             },
-            "data": 1.65,
+            "data": 1.650000000,
             "dims": []
         },
         "mean_ion_charge_state": {
             "attrs": {
                 "units": "dimensionless"
             },
-            "data": 1.0,
+            "data": 1.000000000,
             "dims": []
         },
         "minor_radius": {
             "attrs": {
                 "units": "meter"
             },
-            "data": 0.49,
+            "data": 0.4900000000,
             "dims": []
         },
         "plasma_current": {
             "attrs": {
                 "units": "ampere"
             },
-            "data": 800000.0,
+            "data": 800000.0000,
             "dims": []
         },
         "poloidal_sound_larmor_radius": {
             "attrs": {
                 "units": "millimeter"
             },
-            "data": 4.4794720291352315,
+            "data": 4.479472029,
             "dims": []
         },
         "separatrix_electron_density": {
             "attrs": {
                 "units": "_1e19_per_cubic_metre"
             },
-            "data": 1.443846153846154,
+            "data": 1.443846154,
             "dims": []
         },
         "separatrix_electron_temp": {
             "attrs": {
                 "units": "electron_volt"
             },
-            "data": 57.51724137931035,
+            "data": 57.51724138,
             "dims": []
         },
         "surface_area": {
             "attrs": {
                 "units": "meter ** 2"
             },
-            "data": 40.01085451537566,
+            "data": 40.01085452,
             "dims": []
         },
         "sustainment_power_in_electron_channel": {
             "attrs": {
                 "units": "megawatt"
             },
-            "data": 0.7413990364829475,
+            "data": 0.7413990365,
             "dims": []
         },
         "sustainment_power_in_ion_channel": {
             "attrs": {
                 "units": "megawatt"
             },
-            "data": 0.16744964593929906,
+            "data": 0.1674496459,
             "dims": []
         },
         "target_electron_temp": {
             "attrs": {
                 "units": "electron_volt"
             },
-            "data": 10.0,
+            "data": 10.00000000,
             "dims": []
         },
         "triangularity_psi95": {
             "attrs": {
                 "units": "dimensionless"
             },
-            "data": 0.3,
+            "data": 0.3000000000,
             "dims": []
         },
         "z_effective": {
             "attrs": {
                 "units": "dimensionless"
             },
-            "data": 1.25,
+            "data": 1.250000000,
             "dims": []
         }
     },