sapply - Count previous occurences of a string across multiple columns in R -


i have 4 column matrix chronological index, , 3 columns of names (strings). here toy data:

x = rbind(c(1,"sam","harry","joe"), c(2,"joe","sam","jack"),c(3,"jack","joe","jill"),c(4,"harry","jill","joe"))

i want create 3 additional vectors count (for each row) previous (but not subsequent) occurrences of name. here desired result toy data:

y = rbind(c(0,0,0),c(1,1,0),c(1,2,0),c(1,1,3))

i @ loss of how approach problem, , have searched stack overflow relevant examples. dplyr provides answers finding total counts, (as far can tell) not on row row basis.

i attempted write function deal problem in single-column space, no luck, i.e.

thing = sapply(x,function(i)length(grep(i,x[x[1:i]])))

any tips appreciated.

this typical ave + seq_along type of problem, need convert data vectors first:

t(`dim<-`(ave(rep(1, prod(dim(x[, -1]))),                c(t(x[, -1])), fun = seq_along)  - 1,            rev(dim(x[, -1])))) #      [,1] [,2] [,3] # [1,]    0    0    0 # [2,]    1    1    0 # [3,]    1    2    0 # [4,]    1    1    3

perhaps more readable:

## x without first column vector x_vec <- c(t(x[, -1]))  ## values looking obtain... y_vals <- ave(rep(1, length(x_vec)), x_vec, fun = seq_along) - 1  ## ... in format want obtain them matrix(y_vals, ncol = ncol(x) - 1, byrow = true) #      [,1] [,2] [,3] # [1,]    0    0    0 # [2,]    1    1    0 # [3,]    1    2    0 # [4,]    1    1    3

Comments

Post a Comment

Popular posts from this blog

c++ - Difference between pre and post decrement in recursive function argument -

i have following sample code used pre-decrement void function(int c) { if(c == 0) { return; } else { cout << "dp" << c << endl; function(--c); cout << c << endl; return; } } this function give output input 4 : dp3 dp2 dp1 dp0 0 1 2 3 but when use post decrement void function(int c) { if(c == 0) { return; } else { cout << "dp" << c << endl; function(c--); cout << c << endl; return; } } output goes in infinite loop dp4 can explain me in detail why happens ? this happens because function(c--) called same value of c , when finishes c decremented. recursively called, hence called same value no chance of return , hit stack overflow error. assume this, int x = 1, y = 0; y = x++ result y == 1 , x == 2. if y = ++x , bot x , y 2.
Read more

php - Nothing but 'run(); ' when browsing to my local project, how do I fix this? -

i added new project. made mistake in projectname.conf file in sites-available apache2, led me reinstalling apache2. after reinstalling , re-enabling projects on every page of every project .. <body> run(); </body> .. i've run composer update, restarted service, restarted pc, checked config files, tried disabling new project. there nothing in error log, , access.log: 127.0.0.1 - - [15/may/2015:01:40:47 +0200] "get / http/1.1" 304 181 "-" "mozilla/5.0 (x11; ubuntu; linux x86_64; rv:38.0) gecko/20100101 firefox/38.0" maybe i'm forgetting apache2 reinstall? don't think did different last time installed it. looks haven't setup php correctly. take @ this great guide , maybe you're forgetting link php config apache2.
Read more

php - How can I echo out this array? -

i don't know how go grabbing data in variable , put foreach loop. class tree{ private $info = array( array('name'=>'jim','state'=>'nu','company'=>'nu','phone'=>array('cell'=>'5615111111','office'=>'5611111111'),'email'=>array('primary'=>'exs@example.com','ex@there.com')), array('name'=>'joe smith','city'=>'phoenix','phone'=>'4805551111','email'=>'jsmith@some_email.com'), array('name'=>'john doe','city'=>'chandler','company'=>'doe co.','email'=>array('jdoe@gmail.com','personal'=>'email@email.com'),'phone'=>'6025550002') ); } if you're inside of class, can access private variable using $this->variablename . example, i...
Read more