data processing - Ways to read only select columns from a file into R? (A happy medium between `read.table` and `scan`?) -


इस सवाल का पहले से ही एक उत्तर है: < / P>

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मेरे पास कुछ बहुत बड़ी सीमांकित है डेटा फ़ाइलों और पूरी फाइल के लिए एक data.frame बनाने के लिए समय और मेमोरी न लेने के बाद मैं आर में केवल कुछ कॉलम पर प्रक्रिया करना चाहता हूं।

केवल एक ही विकल्प मुझे पता है read.table जो बहुत बेकार है जब मैं केवल कुछ कॉलम या स्कैन चाहता हूँ जो कि मुझे क्या चाहिए के लिए बहुत कम स्तर लगता है।

क्या कोई बेहतर विकल्प है, या तो शुद्ध आर के साथ या शायद कॉलम निष्कर्षण करने के लिए किसी अन्य शैल स्क्रिप्ट को बुला रहा है और उसके बाद स्कैन या इसके आउटपुट पर readable का उपयोग कर रहा है? (जो कि शेल स्क्रिप्ट को कॉल करने और आर में अपना आउटपुट कैप्चर कैसे कर सकता है)।

कभी-कभी मैं ऐसा कुछ करता हूं जब मेरे पास टैब-सीमांकित फ़ाइल में डेटा होता है: 

  df & lt; - read.table (पाइप ("कट -f1,5,28 myFile.txt"  
 [गलत शुद्ध आर संस्करण हटाया गया है) -  read.table  के लिए  colClasses  तर्क में नल का उपयोग करके सही शुद्ध आर संस्करण देखें।

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