This topic describes the syntax of mathematical statistics functions. This topic also provides examples on how to use the functions.
| Function | Syntax | Description |
|---|---|---|
| corr function | corr(x,y) | Returns the coefficient of correlation between x and y. The return value is in the range of [0,1]. |
| covar_pop function | covar_pop(x,y) | Returns the population covariance of x and y. |
| covar_samp function | covar_samp(x,y) | Returns the sample covariance of x and y. |
| regr_intercept function | regr_intercept(y,x) | Returns the y-intercept of the line for the linear equation that is determined by the (x,y) pair. |
| regr_slope function | regr_slope(y,x) | Returns the slope of the line for the linear equation that is determined by the (x,y) pair. |
| stddev function | stddev(x) | Returns the sample standard deviation of x. This function is equivalent to the stddev_samp function. |
| stddev_samp function | stddev_samp(x) | Returns the sample standard deviation of x. |
| stddev_pop function | stddev_pop(x) | Returns the population standard deviation of x. |
| variance function | variance(x) | Returns the sample variance of x. This function is equivalent to the var_samp function. |
| var_samp function | var_samp(x) | Returns the sample variance of x. |
| var_pop function | var_pop(x) | Returns the population variance of x. |
corr function
The corr function returns the coefficient of correlation between x and y. A larger return value indicates a higher correlation.
Syntax
corr(x,y)Parameters
| Parameter | Description |
|---|---|
| x | The value of this parameter is of the double type. |
| y | The value of this parameter is of the double type. |
Return value type
The double type. The return value is in the range of [0,1].
Examples
Calculate the coefficient of correlation between the values of the request_length and request_time fields.
- Query statement
* | SELECT corr(request_length,request_time) - Query and analysis results
covar_pop function
The covar_pop function returns the population covariance of x and y.
Syntax
covar_pop(x,y)Parameters
| Parameter | Description |
|---|---|
| x | The value of this parameter is of the double type. |
| y | The value of this parameter is of the double type. |
Return value type
The double type.
Examples
Calculate the population covariance of pretax profits and pretax turnovers in each minute.
- Query statement
*| SELECT covar_pop(PretaxGrossAmount, PretaxAmount) AS "Population covariance", time_series(__time__, '1m', '%H:%i:%s', '0') AS time GROUP BY time - Query and analysis results
covar_samp function
The covar_samp function returns the sample covariance of x and y.
Syntax
covar_samp(x,y)Parameters
| Parameter | Description |
|---|---|
| x | The value of this parameter is of the double type. |
| y | The value of this parameter is of the double type. |
Return value type
The double type.
Examples
Calculate the sample covariance of pretax profits and pretax turnovers in each minute.
- Query statement
*| SELECT covar_samp(PretaxGrossAmount, PretaxAmount) AS "Sample covariance", time_series(__time__, '1m', '%H:%i:%s', '0') AS time GROUP BY time - Query and analysis results
regr_intercept function
The regr_intercept function returns the y-intercept of the line for the linear equation that is determined by the (x,y) pair. x is the dependent value. y is the independent value.
Syntax
regr_intercept(y,x)Parameters
| Parameter | Description |
|---|---|
| y | The value of this parameter is of the double type. |
| x | The value of this parameter is of the double type. |
Return value type
The double type.
Examples
Calculate the y-intercept of the line for the linear equation that is determined by the values of the request_time and request_length fields.
- Query statement
* | SELECT regr_intercept(request_length,request_time) - Query and analysis results
regr_slope function
The regr_slope function returns the slope of the line for the linear equation that is determined by the (x,y) pair. x is the dependent value. y is the independent value.
Syntax
regr_slope(y,x)Parameters
| Parameter | Description |
|---|---|
| y | The value of this parameter is of the double type. |
| x | The value of this parameter is of the double type. |
Return value type
The double type.
Examples
Calculate the slope of the line for the linear equation that is determined by the values of the request_time and request_length fields.
- Query statement
* | SELECT regr_slope(request_length,request_time) - Query and analysis results
stddev function
The stddev function returns the sample standard deviation of x. This function is equivalent to the stddev_samp function.
Syntax
stddev(x)Parameters
| Parameter | Description |
|---|---|
| x | The value of this parameter is of the double or bigint type. |
Return value type
The double type.
Examples
Calculate the sample standard deviation and population standard deviation of pretax incomes and display the calculated values in a line chart.
- Query statement
* | SELECT stddev(PretaxGrossAmount) as "Sample standard deviation", stddev_pop(PretaxGrossAmount) as "Population standard deviation", time_series(__time__, '1m', '%H:%i:%s', '0') AS time GROUP BY time - Query and analysis results
stddev_samp function
The stddev_samp function returns the sample standard deviation of x.
Syntax
stddev_samp(x)Parameters
| Parameter | Description |
|---|---|
| x | The value of this parameter is of the double or bigint type. |
Return value type
The double type.
Examples
Calculate the sample standard deviation and population standard deviation of pretax incomes and display the calculated values in a line chart.
- Query statement
* | SELECT stddev_samp(PretaxGrossAmount) as "Sample standard deviation", stddev_pop(PretaxGrossAmount) as "Population standard deviation", time_series(__time__, '1m', '%H:%i:%s', '0') AS time GROUP BY time - Query and analysis results
stddev_pop function
The stddev_pop function returns the population standard deviation of x.
Syntax
stddev_pop(x)Parameters
| Parameter | Description |
|---|---|
| x | The value of this parameter is of the double or bigint type. |
Return value type
The double type.
Examples
Calculate the sample standard deviation and population standard deviation of pretax incomes and display the calculated values in a line chart.
- Query statement
* | SELECT stddev(PretaxGrossAmount) as "Sample standard deviation", stddev_pop(PretaxGrossAmount) as "Population standard deviation", time_series(__time__, '1m', '%H:%i:%s', '0') AS time GROUP BY time - Query and analysis results
variance function
The variance function returns the sample variance of x. This function is equivalent to the var_samp function.
Syntax
variance(x)Parameters
| Parameter | Description |
|---|---|
| x | The value of this parameter is of the double or bigint type. |
Return value type
The double type.
Examples
Calculate the sample variance and population variance of pretax incomes and display the calculated values in a line chart.
- Query statement
* | SELECT variance(PretaxGrossAmount) as "Sample variance", var_pop(PretaxGrossAmount) as "Population variance", time_series(__time__, '1m', '%H:%i:%s', '0') as time GROUP BY time - Query and analysis results
var_samp function
The var_samp function returns the sample variance of x.
Syntax
var_samp(x)Parameters
| Parameter | Description |
|---|---|
| x | The value of this parameter is of the double or bigint type. |
Return value type
The double type.
Examples
Calculate the sample variance and population variance of pretax incomes and display the calculated values in a line chart.
- Query statement
* | SELECT var_samp(PretaxGrossAmount) as "Sample variance", var_pop(PretaxGrossAmount) as "Population variance", time_series(__time__, '1m', '%H:%i:%s', '0') as time GROUP BY time - Query and analysis results
var_pop function
The var_pop function returns the population variance of x.
Syntax
var_pop(x)Parameters
| Parameter | Description |
|---|---|
| x | The value of this parameter is of the double or bigint type. |
Return value type
The double type.
Examples
Calculate the sample variance and population variance of pretax incomes and display the calculated values in a line chart.
- Query statement
* | SELECT variance(PretaxGrossAmount) as "Sample variance", var_pop(PretaxGrossAmount) as "Population variance", time_series(__time__, '1m', '%H:%i:%s', '0') as time GROUP BY time - Query and analysis results