R.Net 用法

浏览数：18 / 时间：2015年06月09日

<br>           using 
(REngine engine = REngine.CreateInstance("RDotNet"))
            {
                engine.Initialize();
                var 
expandGrid = engine.Evaluate("function(x, y) { expand.grid(x=x, y=y) }").AsFunction();
                var 
v1 = engine.CreateIntegerVector(new[] {1, 2, 3});
                var 
v2 = engine.CreateCharacterVector(new[] {"a", "b", "c"});
                var 
df = expandGrid.Invoke(new 
SymbolicExpression[] {v1, v2}).AsDataFrame();
                engine.SetSymbol("cases", df);
                // Not correct: the ‘y‘ column is a "factor". This returns "1", "1", "1", "2", "2", etc. 
                var 
letterCases = engine.Evaluate("cases[,‘y‘]").AsCharacter().ToArray();
                // This returns something more intuitive for C#  Returns ‘a‘,‘a‘,‘a‘,‘b‘,‘b‘,‘b‘,‘c‘ etc.
                letterCases = engine.Evaluate("as.character(cases[,‘y‘])").AsCharacter().ToArray();
                // In the manner of R.NET, try
                letterCases = engine.Evaluate("cases[,‘y‘]").AsFactor().GetFactors();<br><br>　　　　　　　　　　TestDataFrame(engine);
                Console.WriteLine("Press any key to exit the program");
                Console.ReadKey();
            }
 
 
        private 
static 
void 
TestDataFrame(REngine engine)
        {           
            // import csv file
            engine.Evaluate("dataset<-read.table(file.choose(), header=TRUE, sep = ‘,‘)");
            // retrieve the data frame
            DataFrame dataset = engine.Evaluate("dataset").AsDataFrame();
             
            for 
(int 
i = 0; i < dataset.ColumnCount; ++i)
            {
                Console.WriteLine("Column: {0} {1}", i, dataset.ColumnNames[i]);
            }
            for 
(int 
i = 0; i < dataset.RowCount; ++i)
            {
                Console.WriteLine("Row: {0} {1}", i, dataset.RowNames[i]);
                for 
(int 
k = 0; k < dataset.ColumnCount; ++k)
                {
                    Console.WriteLine("Cell[{0},{1}]={2}", i, k, dataset[i, k]);
                }
            }
        }    