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Implement data transforms.
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@prichards-wmko
prichards-wmko committed Jun 17, 2020
1 parent 465a73f commit 37d64f5
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Showing 3 changed files with 134 additions and 22 deletions.
118 changes: 99 additions & 19 deletions pkg/keyword-backend.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -48,13 +48,24 @@ type DatasourceSettings struct {
MetaTable string `json:"metatable"`
}

// Define the unit conversion transforms, this maps onto the unitConversionOptions list in QueryEditor.tsx
// Define the unit conversions, this maps onto the unitConversionOptions list in QueryEditor.tsx
const (
UNIT_CONVERT_NONE = iota
UNIT_CONVERT_DEG_TO_RAD = iota
UNIT_CONVERT_RAD_TO_DEG = iota
UNIT_CONVERT_K_TO_C = iota
UNIT_CONVERT_C_TO_K = iota
UNIT_CONVERT_NONE = iota
UNIT_CONVERT_DEG_TO_RAD = iota
UNIT_CONVERT_RAD_TO_DEG = iota
UNIT_CONVERT_RAD_TO_ARCSEC = iota
UNIT_CONVERT_K_TO_C = iota
UNIT_CONVERT_C_TO_K = iota
)

// Define the data transforms, this maps onto the transformOptions list in QueryEditor.tsx
const (
TRANSFORM_NONE = iota
TRANSFORM_FIRST_DERIVATVE = iota
TRANSFORM_FIRST_DERIVATVE_1HZ = iota
TRANSFORM_FIRST_DERIVATVE_10HZ = iota
TRANSFORM_FIRST_DERIVATVE_100HZ = iota
TRANSFORM_DELTA = iota
)

// LoadSettings gets the relevant settings from the plugin context
Expand Down Expand Up @@ -146,12 +157,12 @@ func (td *KeywordDatasource) QueryData(ctx context.Context, req *backend.QueryDa
}

type queryModel struct {
//Constant string `json:"constant"`
//Datasource string `json:"datasource"`
//DatasourceId string `json:"datasourceId"`
Format string `json:"format"`
QueryText string `json:"queryText"`
UnitConversion int `json:"unitConversion"`
Transform int `json:"transform"`
IntervalMs int `json:"intervalMs"`
MaxDataPoints int `json:"maxDataPoints"`
//OrgId string `json:"orgId"`
Expand Down Expand Up @@ -242,8 +253,9 @@ func (td *KeywordDatasource) query(ctx context.Context, query backend.DataQuery,
times := make([]time.Time, count)
values := make([]float64, count)

var tf float64
var tv, v float64
// Temporary variables for conversions/transforms
var timetemp float64
var valtemp, val float64
var i int32

// Iterate only as many rows as predicted, it's possible more rows arrived after the initial query executed!
Expand All @@ -253,7 +265,7 @@ func (td *KeywordDatasource) query(ctx context.Context, query backend.DataQuery,
if rows.Next() {

// Pull the elements out of the row
err = rows.Scan(&tf, &tv)
err = rows.Scan(&timetemp, &valtemp)
if err != nil {
log.DefaultLogger.Error(fl() + "query scan error: " + err.Error())

Expand All @@ -265,31 +277,35 @@ func (td *KeywordDatasource) query(ctx context.Context, query backend.DataQuery,
}

// Separate the fractional seconds so we can convert it into a time.Time
sec, dec := math.Modf(tf)
sec, dec := math.Modf(timetemp)
times[i] = time.Unix(int64(sec), int64(dec*(1e9)))

// If we are doing a unit conversion, perform it now while we have the single value in hand
switch qm.UnitConversion {

case UNIT_CONVERT_NONE:
// No conversion, just assign it straight over
v = tv
val = valtemp

case UNIT_CONVERT_DEG_TO_RAD:
// RAD = DEG * π/180 (1° = 0.01745rad)
v = tv * (math.Pi / 180)
val = valtemp * (math.Pi / 180)

case UNIT_CONVERT_RAD_TO_DEG:
// DEG = RAD * 180/π (1rad = 57.296°)
v = tv * (180 / math.Pi)
val = valtemp * (180 / math.Pi)

case UNIT_CONVERT_RAD_TO_ARCSEC:
// ARCSEC = RAD * (3600 * 180)/π (1rad = 206264.806")
val = valtemp * (3600 * 180 / math.Pi)

case UNIT_CONVERT_K_TO_C:
// °C = K + 273.15
v = tv + 273.15
val = valtemp + 273.15

case UNIT_CONVERT_C_TO_K:
// K = °C − 273.15
v = tv - 273.15
val = valtemp - 273.15

default:
// Send back an empty frame with an error, we did not understand the conversion
Expand All @@ -298,11 +314,75 @@ func (td *KeywordDatasource) query(ctx context.Context, query backend.DataQuery,
return response
}

values[i] = v
// Assign the value to the result array
values[i] = val
}

// Perform any requested data transforms
switch qm.Transform {

case TRANSFORM_NONE:
break

case TRANSFORM_FIRST_DERIVATVE, TRANSFORM_FIRST_DERIVATVE_1HZ, TRANSFORM_FIRST_DERIVATVE_10HZ, TRANSFORM_FIRST_DERIVATVE_100HZ:

// Compute the first derivative of the data.
dtimes := make([]time.Time, count-1)
dvalues := make([]float64, count-1)

for i = 1; i < count; i++ {
// Calculate the dt
dtimes[i-1] = times[i]

// Calculate the dy/dt
var dt, dvdt float64
dt = (times[i].Sub(times[i-1])).Seconds()
dvdt = (values[i] - values[i-1]) / dt

if qm.Transform == TRANSFORM_FIRST_DERIVATVE_1HZ {
dvdt = math.Round(dvdt)
} else if qm.Transform == TRANSFORM_FIRST_DERIVATVE_10HZ {
dvdt = math.Round(dvdt*10) / 10
} else if qm.Transform == TRANSFORM_FIRST_DERIVATVE_100HZ {
dvdt = math.Round(dvdt*100) / 100
}

dvalues[i-1] = dvdt
}

// Reassign the original arrays to be the 1st derivative results
times = dtimes
values = dvalues

case TRANSFORM_DELTA:
// Compute the deltas of the data. This algorithm replicates what numpy diff() does in Python,
// to the extent that it disregards the time series data. The resultant arrays have one fewer element,
// we drop the 0th element of time and value. It's like a first derivative where dt is always 1.
// See https://numpy.org/doc/stable/reference/generated/numpy.diff.html
dtimes := make([]time.Time, count-1)
dvalues := make([]float64, count-1)

for i = 1; i < count; i++ {
// Bring the time val straight across, shifted by one
dtimes[i-1] = times[i]

// Calculate the dx/dt and assume dt is always 1
dvalues[i-1] = values[i] - values[i-1]
}

// Reassign the original arrays to be the new results
times = dtimes
values = dvalues

default:
// Send back an empty frame with an error, we did not understand the transform
response.Frames = append(response.Frames, empty_frame)
response.Error = fmt.Errorf("Unknown transform: %d", qm.Transform)
return response

}

// get any error encountered during iteration
// Get any error encountered during iteration of the SQL result
err = rows.Err()
if err != nil {
log.DefaultLogger.Error(fl() + "query row error: " + err.Error())
Expand Down Expand Up @@ -511,6 +591,6 @@ func newDataSourceInstance(setting backend.DataSourceInstanceSettings) (instance
}

func (s *instanceSettings) Dispose() {
// Called before creatinga a new instance to allow plugin authors
// Called before creating a a new instance to allow plugin authors
// to cleanup.
}
36 changes: 33 additions & 3 deletions src/QueryEditor.tsx
View file
Original file line number Diff line number Diff line change
Expand Up @@ -32,8 +32,9 @@ export class QueryEditor extends PureComponent<Props> {
{ label: 'none', value: 0 },
{ label: 'degrees to radians', value: 1 },
{ label: 'radians to degrees', value: 2 },
{ label: 'Kelvin to Celcius', value: 3 },
{ label: 'Celcius to Kelvin', value: 4 },
{ label: 'radians to arcseconds', value: 3 },
{ label: 'Kelvin to Celcius', value: 4 },
{ label: 'Celcius to Kelvin', value: 5 },
];

onUnitConversionChange = (item: any) => {
Expand All @@ -42,6 +43,21 @@ export class QueryEditor extends PureComponent<Props> {
onRunQuery();
};

transformOptions = [
{ label: 'none', value: 0 },
{ label: '1st derivative (no rounding)', value: 1 },
{ label: '1st derivative (1Hz rounding)', value: 2 },
{ label: '1st derivative (10Hz rounding)', value: 3 },
{ label: '1st derivative (100Hz rounding)', value: 4 },
{ label: 'delta', value: 5 },
];

onTransformChange = (item: any) => {
const { onChange, query, onRunQuery } = this.props;
onChange({ ...query, transform: item.value });
onRunQuery();
};

render() {
const datasource = this.props.datasource;
const query = defaults(this.props.query, defaultQuery);
Expand Down Expand Up @@ -81,7 +97,7 @@ export class QueryEditor extends PureComponent<Props> {
Units conversion
</InlineFormLabel>
<Select
width={20}
width={30}
placeholder={'none'}
defaultValue={0}
options={this.unitConversionOptions}
Expand All @@ -90,6 +106,20 @@ export class QueryEditor extends PureComponent<Props> {
onChange={this.onUnitConversionChange}
/>
</div>
<div className="gf-form-inline">
<InlineFormLabel width={10} className="transform" tooltip={<p>Transform data.</p>}>
Transform
</InlineFormLabel>
<Select
width={30}
placeholder={'none'}
defaultValue={0}
options={this.transformOptions}
value={query.transform}
allowCustomValue={false}
onChange={this.onTransformChange}
/>
</div>
</>
);
}
Expand Down
2 changes: 2 additions & 0 deletions src/types.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -5,10 +5,12 @@ export interface KeywordQuery extends DataQuery {
service: string;
keyword: string;
unitConversion: number;
transform: number;
}

export const defaultQuery: Partial<KeywordQuery> = {
unitConversion: 0,
transform: 0,
};

/**
Expand Down

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