DataSets[Builtin][Reference]
ApplyToRows
create a Matrix of transformed data with algebraic expressions
Calling Sequence
Parameters
Description
Examples
Compatibility
ApplyToRows(ref, aexp1, aexp2, ..., aexpN)
ref
-
reference to built-in data
aexp1, aexp2, ..., aexpN
algebraic expressions where the indeterminants are column names of ref as Maple names
The ApplyToRows command creates Matrix of transformed data.
The number of columns is equal to the number of algebraic expressions. The number of rows is equal to the number of rows in ref.
The value of the i,j-th entry is the j-th algebraic expression evaluated with the column names substituted for the values in those columns in the i-th row of ref.
Time series data in the reference object are treated as their newest value when using this command.
with⁡DataSets:
ref≔Reference⁡Builtin,CountryCanada,USA,Airports,Heliports
ref≔Country (Name)AirportsHeliportsCanada146726USA135135287
Find the airport to heliport ratio in Canada and the USA
ApplyToRows⁡refCanada,USA,AirportsHeliports
146726135135287
To also have the absolute number of airports in the first column
ApplyToRows⁡refCanada,USA,Airports,AirportsHeliports
146714672613513135135287
The DataSets[Builtin][Reference][ApplyToRows] command was introduced in Maple 2015.
For more information on Maple 2015 changes, see Updates in Maple 2015.
See Also
DataSets
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