处理数据是一条DNA序列：
GCPlot = function(inputsequence, windowsize)
{
starts = seq(1, length(inputsequence), by = windowsize);
n = length(starts);
gensGCs = numeric(n);
for(i in 1:n){
chunk = inputsequence[starts:(starts+windowsize-1)];
gensGC = GC(chunk, NA.GC = NA);
gensGCs <- gensGC; ##这步貌似没有实现，gensGCs的输出数据是5个零
print(gensGC);
}
plot(starts, gensGCs,type = "b"); ##
}
运行后plot图没有显示，且有以下运行错误：
Error in if (na + nc + ng + nt == 0) { :
missing value where TRUE/FALSE needed
