Change measurements

This tutorial shows how to update metadata, fix item values, and remove erroneous points.

Physical background

Not applicable. This tutorial focuses on editing stored data.

Function overview

update_measurement edits measurement metadata and location.
update_item edits a measurement item and its value representation.
delete_item removes a single item.
delete_measurement removes a measurement and its items.

Inputs and outputs

Function	Input	Output	Description
`update_measurement`	measurement id, updates	bool	Update measurement fields.
`update_item`	item id, updates	bool	Update item fields or representation.
`delete_item`	item id	bool	Delete one item.
`delete_measurement`	measurement id	bool	Delete measurement and items.

General workflow

Scenario A: staged fault test correction

Export a JSON snapshot as a backup.
Update the measurement description and operator.
Correct the impedance value at the wrong distance.
Re-run distance-profile analytics.

Scenario B: soil survey correction

Export a JSON snapshot.
Fix an incorrect spacing or unit.
Remove an outlier point.
Rebuild the soil profile and check the curve.

Python API examples

Scenario A: staged fault test correction

from groundmeas.db import connect_db, update_measurement, update_item
from groundmeas.analytics import distance_profile_value

connect_db("groundmeas.db")

update_measurement(1, {
    "description": "Retested after maintenance",
    "operator": "Ops Team",
})

update_item(10, {
    "measurement_type": "earthing_impedance",
    "frequency_hz": 50.0,
    "value": 0.34,
    "value_angle_deg": 0.0,
    "unit": "ohm",
    "measurement_distance_m": 50.0,
})

check = distance_profile_value(1, algorithm="minimum_gradient")
print(check["result_value"])

Scenario B: soil survey correction

from groundmeas.db import connect_db, update_item, delete_item
from groundmeas.analytics import soil_resistivity_profile

connect_db("groundmeas.db")

# Fix spacing and unit for item 21
update_item(21, {
    "measurement_type": "soil_resistivity",
    "measurement_distance_m": 4.0,
    "value": 60.0,
    "unit": "ohm-m",
})

# Remove an outlier
ok = delete_item(22)
print(ok)

profile = soil_resistivity_profile(2, method="wenner")
print(profile)

CLI examples

Scenario A: staged fault test correction

gm-cli export-json backup.json --measurement-id 1

gm-cli edit-measurement 1

gm-cli edit-item 10

gm-cli distance-profile 1 --type earthing_impedance --algorithm minimum_gradient

Scenario B: soil survey correction

gm-cli export-json backup.json --measurement-id 2

gm-cli edit-item 21

gm-cli delete-item 22 --yes

gm-cli soil-profile 2 --method wenner

Additional notes

When changing value representation, clear unused fields to avoid stale values.
Always export a backup before deleting items.
If you adjust spacing, re-check the profile and inversion results.