※ 引述《FDBDB (TEJ)》之銘言： : 請問板上各位高手 : 當我今天先行給定兩個變數各 n 個值(如以下的greed1和greed2) : 而我想利用這些值做出 n^2 種組合 : 並把其寫成一成 (n^2)*2 之資料矩陣 : 以下是我自己就n等於12的時候寫出來之矩陣 : 但一旦n改變則全部都要變動 : 想請問有哪種比較一般化的語法比較適合寫這種矩陣嗎 : 麻煩各位了 : greed1<-c(0.6000000, 0.6272727, 0.6545455, 0.6818182, 0.7090909, 0.7363636, 0.7636364, 0.7909091, 0.8181818, 0.8454545, 0.8727273, 0.9000000) : alpha1<-as.matrix(greed1) : greed2<-c(0.3000000, 0.3272727, 0.3545455, 0.3818182, 0.4090909, 0.4363636, 0.4636364, 0.4909091, 0.5181818, 0.5454545, 0.5727273, 0.6000000) : alpha2<-as.matrix(greed2) : alpha1_2=matrix(data=NA,nrow=(dim(alpha1)[1]*dim(alpha2)[1]),ncol=2,byrow=T) 使用 rep 抓取 matrix data alpha1_2[,1]<-alpha1[rep(1:12,each=12),] alpha1_2[,2]<-alpha2[rep(1:12,12),] : alpha1_2[1:12,1] =alpha1[1,] : alpha1_2[13:24,1] =alpha1[2,] : alpha1_2[25:36,1] =alpha1[3,] : alpha1_2[37:48,1] =alpha1[4,] : alpha1_2[49:60,1] =alpha1[5,] : alpha1_2[61:72,1] =alpha1[6,] : alpha1_2[73:84,1] =alpha1[7,] : alpha1_2[85:96,1] =alpha1[8,] : alpha1_2[97:108,1]=alpha1[9,] : alpha1_2[109:120,1]=alpha1[10,] : alpha1_2[121:132,1]=alpha1[11,] : alpha1_2[133:144,1]=alpha1[12,] : for (b in 1:12){ : alpha1_2[b,2]=alpha2[b,] : } : for (c in 13:24){ : alpha1_2[c,2]=alpha2[c-12,] : } : for (d in 25:36){ : alpha1_2[d,2]=alpha2[d-24,] : } : for (e in 37:48){ : alpha1_2[e,2]=alpha2[e-36,] : } : for (f in 49:60){ : alpha1_2[f,2]=alpha2[f-48,] : } : for (g in 61:72){ : alpha1_2[g,2]=alpha2[g-60,] : } : for (h in 73:84){ : alpha1_2[h,2]=alpha2[h-72,] : } : for (j in 85:96){ : alpha1_2[j,2]=alpha2[j-84,] : } : for (k in 97:108){ : alpha1_2[k,2]=alpha2[k-96,] : } : for (l in 109:120){ : alpha1_2[l,2]=alpha2[l-108,] : } : for (m in 121:132){ : alpha1_2[m,2]=alpha2[n-120,] : } : for (n in 133:144){ : alpha1_2[n,2]=alpha2[m-132,] : } --

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