寻求Base R优质学习资源及data frame列字符串计数方法

Since you prefer sticking to Base R first, here are some go-to, built-in resources that don't require external links:

• Official Base R Reference Manual: Type help.start() in your R console—this opens a local web page with the complete Base R documentation, organized by function categories (data frames, statistics, string manipulation, etc.). It's the most authoritative source.
• Categorized Function List: Run library(help = "base") to get a grouped list of all Base R functions. This is perfect for keyword searching—if you need data frame tools, scan the "Data Frames" section; for string operations, check "Character Strings".
• apropos() for Recalling Function Names: When you can't remember a function's exact name but know part of it, use apropos("keyword") (e.g., apropos("count") or apropos("subset")) to get a list of matching Base R functions. This is a lifesaver for when you can't use help because you don't know the function name.
• Built-in Demos and Tutorials: Type demo() to see a list of interactive demos that showcase Base R features. For deeper dives, vignette() can sometimes pull up core R vignettes (though most are for packages, a few cover Base R basics).

内容的提问来源于stack exchange，提问作者ryan leman