R data frame from data stored in a variable length concatenated string -

-

i have data frame contains number of features against id delimited |:

df = data.frame(id = c("1","2","3"),  features = c("1|2|3","4|5","6|7") ) df

my goal have column each feature , indicator of presence id e.g.

id | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 |
2 | 0 | 0 | 0 | 1 | 1 | 0 | 0 |
3 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |

the features stored in different table complete list of possible features available better if generate dynamically.

my first attempt use horribly slow loop grepl() populate pre created matrix 'm' e.g.

  (i in 1:dim(df)[1]){   print(i)   if(grepl("1\\|", df$feature[i])) {m[i,1] <- 1}   if(grepl("2\\|", df$feature[i])) {m[i,2] <- 1}   if(grepl("3\\|", df$feature[i])) {m[i,3] <- 1}   if(grepl("4\\|", df$feature[i])) {m[i,4] <- 1}   if(grepl("5\\|", df$feature[i])) {m[i,5] <- 1}   if(grepl("6\\|", df$feature[i])) {m[i,6] <- 1}   if(grepl("7\\|", df$feature[i])) {m[i,7] <- 1} }

ignoring fact regex fall on when features teens. terribly slow on ~400,000 rows need run over. additionally need create if() every single id instead of happening dynamically.

is there way more succinctly dynamic column generation?

the natural object return matrix. here way in base r.

# split features column pipe symbol  , subset result, dropping pipes temp <- lapply(strsplit(as.character(df$features), split="|"), function(i) i[i != "|"]) # use %in% return logical vector of desired length, convert integer , rbind list mymat <- do.call(rbind, lapply(temp, function(i) as.integer(1:7 %in% i))) # add id row names  rownames(mymat) <- df$id

this returns

mymat   [,1] [,2] [,3] [,4] [,5] [,6] [,7] 1    1    1    1    0    0    0    0 2    0    0    0    1    1    0    0 3    0    0    0    0    0    1    1

if want data.frame, can use 

temp <- lapply(strsplit(as.character(df$features), split="|"), function(i) i[i != "|"]) mydf <- cbind(id=df$id, data.frame(do.call(rbind,                                           lapply(temp, function(i) as.integer(1:7 %in% i)))))

which returns

mydf   df$id x1 x2 x3 x4 x5 x6 x7 1     1  1  1  1  0  0  0  0 2     2  0  0  0  1  1  0  0 3     3  0  0  0  0  0  1  1

Comments

Post a Comment

Popular posts from this blog

magento2 - Magento 2 admin grid add filter to collection -

-
i created grid in admin xml ui components. need filter collection via url parameter , dont know how achieve that. tried inject requestinterface collection, filter didnt work. di.xml <virtualtype name="slidelistingdataprovider" type="magento\framework\view\element\uicomponent\dataprovider\dataprovider"> <arguments> <argument name="collection" xsi:type="object" shared="false">xxx\xxx\model\resourcemodel\grid\slide\collection</argument> <argument name="filterpool" xsi:type="object" shared="false">slidelistingfilterpool</argument> <!-- define new object filters --> </arguments> </virtualtype> <virtualtype name="slidelistingfilterpool" type="magento\framework\view\element\uicomponent\dataprovider\filterpool"> <arguments> <argument name="applier...
Read more

Android volley - avoid multiple requests of the same kind to the server? -

-
i using volley upload list of images server. happens within service. once image uploaded remove list. problem arises when internet connection breaks. when internet connection breaks , comes again thinking of adding images yet uploaded request queue. this can result in more 1 copy of same image saved on server request same image might have gone through before getting rseponse. how can address scenario? i'm not quite sure why you're using service schedule requests volley automatically runs it's request in seperate thread. nevertheless can listen both request results, successful , unsuccessful adding listeners. you can remove image list schedule request using volley. if succeeds can carry on desired, if fails can add again list. public static request getimageuploadrequest(final string image) { response.listener<t> responselistener = new response.listener<t>() { @override public void onresponse(t response...
Read more

Combining PHP Registration and Login into one class with multiple functions in one PHP file -

-
i'm trying combine registration, activation , login scripts php website backend script front end developer can pass variables different forms to. my question whether appropriate approach this. don't want have lot of php files different pieces of application developing. far have written following 2 functions login, register , activate user front end developer can call: <?php /** * created phpstorm. * user: karl * date: 26/07/2016 * time: 02:25 */ class users { function register_user($email, $password, $user_name) { $server_name = "localhost"; $u_name = "root"; $db_password = "root"; $db_name = "betamath_graspe"; //email notification variable $from_address="info@slack.com"; //registration form $msg_reg_user='username taken. please choose different username'; $msg_reg_email='email registered'; $msg_reg_active=...
Read more