R 语言DataFrame 排序

Sort:
dd <- data.frame(b = factor(c("Hi","Med","Hi","Low"),
      levels = c("Low","Med","Hi"), ordered = TRUE),
      x = c("A","D","A","C"), y = c(8,3,9,9),
      z = c(1,1,1,2))
sort by column z (descending) then by column b (ascending)
1). dd[with(dd, order(-z, b)),]
2). dd[ order(-dd[,4], dd[,1]),]
 REngine engine = REngine.GetInstanceFromID("RDotNet");
 DataTable table = new DataTable();
 engine.EagerEvaluate("myDataFrame <- data.frame('Order' =
c(1,2,3,4,5),'Name' = c('Bob', 'Ryan', 'Mel', 'Mark', 'Ali'))");
 DataFrame dataset = engine.EagerEvaluate("myDataFrame").AsDataFrame();
 dataGridView_DF.DataSource = dataset;

public enum IrisSpecies
{
   setosa = 1,
   versicolor = 2,
   virginica = 3,
}
 
[DataFrameRow]
public class IrisData
{
   [DataFrameColumn("Sepal.Length")]
   public double SepalLength { get; set; }
   [DataFrameColumn("Sepal.Width")]
   public double SepalWidth { get; set; }
   [DataFrameColumn("Petal.Length")]
   public double PetalLength { get; set; }
   [DataFrameColumn("Petal.Width")]
   public double PetalWidth { get; set; }
   [DataFrameColumn("Species")]
   public IrisSpecies Species { get; set; }
}
 
var iris = engine.Evaluate("iris").AsDataFrame();
foreach (var row in iris.GetRows<IrisData>())
{
   Console.WriteLine(row.Species);
}