LoopWhile
LoopWhile iterates over a set of commands under the control of one or more logical expressions. Since the logical conditions typically depend upon values in the data, commands executed in a LoopWhile cannot be anticipated and expanded in SDTL.
Properties
Name |
Type |
Description |
|
|---|---|---|---|
Condition |
0..1 |
Describes a condition required for the next iteration to begin. |
|
EndCondition |
0..1 |
Describes a condition that ends interation. |
|
Commands |
1..n |
Commands within the loop. |
|
Updated |
0..1 |
When TRUE, the loop has been expanded into separate commands. |
Properties Inherited from TransformBase
Name |
Type |
Description |
|
|---|---|---|---|
ProducesDataframe |
0..n |
Signify the dataframe which this transform produces. |
|
ConsumesDataframe |
0..n |
Signify the dataframe which this transform acts upon. |
Properties Inherited from CommandBase
Name |
Type |
Description |
|
|---|---|---|---|
Command |
1..1 |
The type of command |
|
SourceInformation |
0..n |
Information about the source of the command. |
|
MessageText |
0..n |
Adds a message that can be displayed with the command. |
Item Type Hierarchy
- CommandBase
- TransformBase
LoopWhile
Relationships
The following identified item types reference this type.
SPSS_example_LoopWhile
========= SPSS EXAMPLE ================
LOOP IF (Y GT 10). COMPUTE X=X+1. END LOOP IF (X EQ 5).
{"Command": "LoopWhile",
"sourceInformation": {
"originalSourceText": "LOOP IF (Y GT 10).
COMPUTE X=X+1.
END LOOP IF (X EQ 5). "
},
"Condition":
{"$type":"FunctionCallExpression",
"Function": "gt",
"IsSDTLName":"True",
"Arguments": [
{"ArgumentName": "EXP1",
"ArgumentValue":
{"$type": "VariableSymbolExpression", "VariableName": "Y"}
},
{"ArgumentName": "EXP2",
"ArgumentValue":
{"$type": "NumericConstantExpression", "Value": "10"}
}
]
},
"EndCondition":
{"$type":"FunctionCallExpression",
"Function": "eq",
"IsSDTLName":"True",
"Arguments": [
{"ArgumentName": "EXP1",
"ArgumentValue":
{"$type": "VariableSymbolExpression", "VariableName": "X"}
},
{"ArgumentName": "EXP2",
"ArgumentValue":
{"$type": "NumericConstantExpression", "IteratorSymbolName": "5"}
}
]
},
"IteratorCommands:" [
{"Command": "compute",
"VariableName":
{"$type": "VariableSymbolExpression", "VariableName": "X"},
"Expression":
{"$type":"FunctionCallExpression",
"Function": "Addition",
"IsSDTLName":"True",
"Arguments": [
{"ArgumentName": "EXP1",
"ArgumentValue":
{"$type": "VariableSymbolExpression", "VariableName": "X"},
},
{"ArgumentName": "EXP2",
"ArgumentValue":
{"$type": "NumericConstantExpression", "IteratorSymbolName": "1"}
}
]
}
}
]
}
Stata_example_LoopWhile
======== Stata EXAMPLE ===============
while `i'<40 {
gen newvar`i' = runiform()
local i=`i'+1
}
{"Command": "LoopWhile",
"sourceInformation": {
"originalSourceText": "while `i'<40 {
gen newvar`i' = runiform()
local i=`i'+1
}"
},
"Condition":
{"$type":"FunctionCallExpression",
"Function": "lt",
"IsSDTLName":"True",
"Arguments": [
{"ArgumentName": "EXP1",
"ArgumentValue":
{"$type": "IteratorSymbolExpression", "IteratorSymbolName": "i"}
},
{"ArgumentName": "EXP2",
"ArgumentValue":
{"$type": "NumericConstantExpression", "Value": "40"}
}
]
},
"IteratorCommands:" [
{"Command": "compute",
"VariableName":
{"CompositeVariableName":
{"Stub": "newvar",
"Postfix":
{"$type": "IteratorSymbolExpression", "IteratorSymbolName": "i"}
}
},
"Expression":
{"$type":"FunctionCallExpression",
"Function": "random_variable_uniform",
"IsSDTLName":"True",
"Arguments": [
{"ArgumentName": "EXP1",
"ArgumentValue":
{"$type": "NumericConstantExpression", "Value": "0"},
},
{"ArgumentName": "EXP2",
"ArgumentValue":
{"$type": "NumericConstantExpression", "Value": "1"}
}
]
}
}
]
}