如何修改此矩​​阵R？

Question

我有一个名为dx的矩阵：

     a b c d e f g h

cat  0 0 0 0 0 0 0 0 

dog  1 0 1 0 0 0 0 1

fish 1 1 1 0 0 0 0 0 

egg  0 0 0 0 0 0 0 0 

如何删除像猫和蛋一样全部为零的行。这样我才能最终得到这个 -

     a b c d e f g h

dog  1 0 1 0 0 0 0 1

fish 1 1 1 0 0 0 0 0 

Answer 1

您可以尝试这样的事情：

m<-matrix(c(1,1,1,0,
        0,0,0,0,
        1,0,1,0,
        0,0,0,0,
        1,1,1,1),ncol=4,byrow=T)
m[rowSums(abs(m))!=0,]

Answer 2

public void Configuration(IAppBuilder app)
{
     app.UseHandlerAsync((req, res) =>
    {
        Console.Clear();
        foreach (var item in req.Headers)
        {
            Console.WriteLine(item.Key + ":" );
            foreach (var item1 in item.Value)
            {
                Console.Write(item1);
            }
        }
        //res.Headers.AcceptRanges.Add("bytes");
        //result.StatusCode = HttpStatusCode.OK;
        //result.Content = new StreamContent(st);
        //result.Content.Headers.ContentLength = st.Length;

        res.Headers.Add("ContentType" ,new string[]{"application/octet-stream"});
         res.SendFileAsync(Directory.GetCurrentDirectory() + @"\1.mp3");
        // res.ContentType = "text/plain";
         return res.WriteAsync("Hello, World!");
    });
}