dataframe - r subset rows by criteria and by factor group -

-

i have data.frame lot of nas:

df <- data.frame(a = rep(letters[1:3], each = 3),                   b = c(na, na, na, 1, na, 3, na, na, 7)) df > df    b 1 na 2 na 3 na 4 b  1 5 b na 6 b  3 7 c na 8 c na 9 c  7

i subset dataframe obtain factor group rows have no less 2 values, such this:

   b 1 b 1 2 b na 3 b 3

i have tried function doesn't work:

subset(df, sum(!is.na(b)) < 1, = a)  > [1] b <0 rows> (or 0-length row.names)

any suggestion? (other packages solutions welcome)

we can use data.table. convert 'data.frame' 'data.table' (setdt(df)), grouped 'a', if sum of logical vector (i.e. non-na elements - !is.na(b)) greater 1, subset data.table.

library(data.table) setdt(df)[,if(sum(!is.na(b))>1) .sd , = a] #    b #1: b  1 #2: b na #3: b  3

or using dplyr, same logic, after grouping 'a', filter rows.

library(dplyr) df %>%      group_by(a) %>%     filter(sum(!is.na(b))>1) #          b #  <fctr> <dbl> #1      b     1 #2      b    na #3      b     3

or in base r ave

df[with(df, ave(b, a, fun = function(x) sum(!is.na(x))>1)!=0),]

Comments

Post a Comment

Popular posts from this blog

Spring Boot + JPA + Hibernate: Unable to locate persister -

-
i trying work entity inside request method of spring boot application. entity in project , pom.xml has dependencies it. why error message?: org.hibernate.unknownentitytypeexception: unable locate persister: com.ric.bill.model.bs.par package com.ric.web; import java.util.concurrent.atomic.atomiclong; import javax.persistence.entitymanager; import javax.persistence.persistencecontext; import net.sf.ehcache.cachemanager; import net.sf.ehcache.management.cache; import net.sf.ehcache.management.cachestatistics; import org.hibernate.stat.statistics; import org.springframework.beans.factory.annotation.autowired; import org.springframework.boot.autoconfigure.domain.entityscan; import org.springframework.cache.annotation.enablecaching; import org.springframework.transaction.annotation.enabletransactionmanagement; import org.springframework.transaction.annotation.propagation; import org.springframework.transaction.annotation.transactional; import org.springframework.web.bind.annotati
Read more

go - Golang: panic: runtime error: invalid memory address or nil pointer dereference using bufio.Scanner -

-
i implementing go program uses bufio.scanner , bufio.writer have packaged code follows package main import ( "fmt" "player/command" "strings" ) func main() { //enter code here. read input stdin. print output stdout commands.scanner.scan() { //scan new line , send comand variable check command exist or not input := strings.split(strings.trim(commands.scanner.text(), " "), " ") command := input[0] if command == "" { fmt.printf("$ %s:", commands.pwd) continue } if !commands.commands[command] { commands.throwerror("cannot recognize input.") } else { commands.execute(command, input[1:], nil) } fmt.printf("$ %s:", commands.pwd) } } i using init.go file in main package follows package main import ( "flag" "player/sourc
Read more

c - double free or corruption (fasttop) -

-
this code reads null terminated string file (file containing null terminated strings & should provide index wanted string). error: *** error in `./main': double free or corruption (fasttop): 0x090a4a80 *** aborted code: char *tmp_realloc=null; char *sstring=null; int i=1; /*set file pointer point string*/ fseek(fh,index,seek_set); sstring=(char*)malloc(sizeof(char)); if(sstring == null) return null; tmp_realloc=sstring; while( (*(sstring+i-1)=(char)fgetc((file*)fh)) != 0x0 ) { /*reallocate more memory*/ tmp_realloc=(char*)realloc((char*)sstring,++i); /*if not same address copy old new & set old point new*/ if(tmp_realloc != sstring){ strcpy((char*)tmp_realloc,(char*)sstring); free(sstring); sstring=tmp_realloc; } } could tell me pointer causing issue (& reason) ? remove part /*if not same address copy old new & set old point new*/ if(tmp_realloc != sstring){ strc
Read more