Draws a double-headed arrow.
Syntax
result = pd.Cov (variable1, variable2)
result = pd.Cov (variable1, variable2, covarianceValue)
result = pd.Cov (variable1, variable2, covarianceName)
result = pd.Cov (variableName1, variableName2)
result = pd.Cov (variableName1, variableName2, covarianceValue)
result = pd.Cov (variableName1, variableName2, covarianceName)
The Cov method syntax has the following parts:
| Part | Description | 
| result | (Object of type PDElement) The new double-headed arrow. | 
| variable1, variable2 | (Objects of type PDElement) The two variables to be connected by the new double-headed arrow. | 
| variableName1, variableName2 | (Strings) Names of the two variables to be connected by the new double-headed arrow. | 
| covarianceValue | (Double) The value of the covariance represented by the new double-headed arrow. | 
| covarianceName | (String) A name for the covariance represented by the new double-headed arrow. | 
Remarks
If you do not specify a name or value for the covariance represented by the double-headed arrow, the covariance will be unconstrained.