换句话说,我想要多少小于2600的bwt (体重)是年龄<20和吸烟== 1。for loop to calculate the low weight
for (i in 1:length(new_df$bwt)){low_weight_tot <- 0for (i in 1:length(birthwt$bwt)){
if(bwt[i] < 2600
T 2600-28TS GPL代码 1.All build targets are in "t2600g-28ts_gpl/tplink/buildroot-wolfhound2/" and "t2600g-28ts_gpl/ldk/XLDK:/project/trunk/t2600g-28ts_gpl/tplink/buildroot-wolfhound2/host