r - why all date strings are changed into numbers? - 


start=as.date("2013-09-02") x[1:140]<-start for(i in 2:140){   x[i]<-x[i-1]+1 }

what such:

[1] "2013-09-02" "2013-09-03" "2013-09-04" "2013-09-05" "2013-09-06"

when run :

y<-matrix(x,nrow=20,byrow=true)  > y     [,1]  [,2]  [,3]  [,4]  [,5]  [,6]  [,7]  [1,] 15950 15951 15952 15953 15954 15955 15956

all string changed numbers,why?how can not change them in y?

the problem r doesn't allow matrices populated dates. both "matrix" , "date" classes. underlying representation of date object in r integer. when create matrix y, takes underlying data x (which array of integers), adds dimension attribute, , makes class "matrix".

there's not clean way around problem. there few hacks can use, though. example, explicitly force y of class "date" "matrix" class(y)<-c("matrix","date"). y still print out vector of dates, able manipulate using matrix cordinates:

> class(y)<-c("matrix","date") > head(y)  [1] "2013-09-02" "2013-09-09" "2013-09-16" "2013-09-23" "2013-09-30"  [6] "2013-10-07" "2013-09-03" "2013-09-10" "2013-09-17" "2013-09-24" [11] "2013-10-01" "2013-10-08" "2013-09-04" "2013-09-11" "2013-09-18" [16] "2013-09-25" "2013-10-02" "2013-10-09" "2013-09-05" "2013-09-12" [21] "2013-09-19" "2013-09-26" "2013-10-03" "2013-10-10" "2013-09-06" [26] "2013-09-13" "2013-09-20" "2013-09-27" "2013-10-04" "2013-10-11" [31] "2013-09-07" "2013-09-14" "2013-09-21" "2013-09-28" "2013-10-05" [36] "2013-10-12" "2013-09-08" "2013-09-15" "2013-09-22" "2013-09-29" [41] "2013-10-06" "2013-10-13" > y[1,] [1] "2013-09-02" "2013-09-03" "2013-09-04" "2013-09-05" "2013-09-06" [6] "2013-09-07" "2013-09-08" > y[1,]<-y[1,]+1 > y[1,] [1] "2013-09-03" "2013-09-04" "2013-09-05" "2013-09-06" "2013-09-07" [6] "2013-09-08" "2013-09-09"

you use data frame instead of matrix: 

> y<-data.frame(y) > y<-data.frame(lapply(y,function(x) {class(x)<-"date";x})) > head(y)           x1         x2         x3         x4         x5         x6         x7 1 2013-09-02 2013-09-03 2013-09-04 2013-09-05 2013-09-06 2013-09-07 2013-09-08 2 2013-09-09 2013-09-10 2013-09-11 2013-09-12 2013-09-13 2013-09-14 2013-09-15 3 2013-09-16 2013-09-17 2013-09-18 2013-09-19 2013-09-20 2013-09-21 2013-09-22 4 2013-09-23 2013-09-24 2013-09-25 2013-09-26 2013-09-27 2013-09-28 2013-09-29 5 2013-09-30 2013-10-01 2013-10-02 2013-10-03 2013-10-04 2013-10-05 2013-10-06 6 2013-10-07 2013-10-08 2013-10-09 2013-10-10 2013-10-11 2013-10-12 2013-10-13

a third possiblity keep elements in y in character format, , convert them dates using as.date when need them:

> y<-matrix(as.character(x),nrow=20,byrow=t) > head(y)      [,1]         [,2]         [,3]         [,4]         [,5]         [1,] "2013-09-02" "2013-09-03" "2013-09-04" "2013-09-05" "2013-09-06" [2,] "2013-09-09" "2013-09-10" "2013-09-11" "2013-09-12" "2013-09-13" [3,] "2013-09-16" "2013-09-17" "2013-09-18" "2013-09-19" "2013-09-20" [4,] "2013-09-23" "2013-09-24" "2013-09-25" "2013-09-26" "2013-09-27" [5,] "2013-09-30" "2013-10-01" "2013-10-02" "2013-10-03" "2013-10-04" [6,] "2013-10-07" "2013-10-08" "2013-10-09" "2013-10-10" "2013-10-11"      [,6]         [,7]         [1,] "2013-09-07" "2013-09-08" [2,] "2013-09-14" "2013-09-15" [3,] "2013-09-21" "2013-09-22" [4,] "2013-09-28" "2013-09-29" [5,] "2013-10-05" "2013-10-06" [6,] "2013-10-12" "2013-10-13" > as.date(y[1,]) [1] "2013-09-02" "2013-09-03" "2013-09-04" "2013-09-05" "2013-09-06" [6] "2013-09-07" "2013-09-08"

Comments

Post a Comment

Popular posts from this blog

c++ - CryptStringToBinary API behavior -

i seeing strange behavior cryptstringtobinary cryptography api. please see below code (config: x64 debug): #include "stdafx.h" #include <windows.h> #include <strsafe.h> #include <iostream> #include <exception> void main() { dword dwskip; dword dwflags; dword dwdatalen; //lpcwstr pszinput = l"jaaaaaecaaadzgaaakqaagdnnl1l56bwgfjdgr3rpxtqqqn6daw3usv2emkjym4t"; //this works fine lpcwstr pszinput = l"mytest"; //doesnt work, api returns false,error code 0x0000000d // determine size of byte array , allocate memory. if(! cryptstringtobinary( pszinput, _tcslen( pszinput ) + 1, crypt_string_base64, null, &dwdatalen, &dwskip, &dwflags ) ) { dword dw = getlasterror(); //0x0000000d: data invalid throw std::exception( "error computing byte length." ); } byte *pbytebyte = null; try { ...
Read more

c++ - Correct method for redrawing a layered window -

i have window created ws_ex_layered window style. drawing onto memory bitmap using gdi+, , using updatelayeredwindow update graphical content of layered window. intend use window main window of application, require redraw frequently. seeing layered windows not receive wm_paint windows message [?] , need come appropriate method re-drawing window. optimisation not essential , it's nice have cake , eat too. therefore, in search of "correct" method use. here thoughts far: i guess it's idea render onto off-screen bitmap before bitblt ing or similar. 60 frames rendered per second should (more than?) enough (but how compare other applications' frame rates?). possible solutions: use settimer send wm_timer message on regular basis. useful because through specifying time-out value, can achieve desired frames per second, without requirement measure duration "frame" takes rendered. would cause input or other lags due frequency , speed of m...
Read more

java.util.scanner - How to read and add only numbers to array from a text file -

i'm learning java , have question regarding reading file want read numbers file contains strings well. here example of file: 66.56 "3 java 3-43 5-42 2.1 1 and here coding: public class test { public static void main (string [] args){ if (0 < args.length) { file x = new file(args[0]); try{ scanner in = new scanner( new fileinputstream(x)); arraylist<double> test = new arraylist<>(); while(in.hasnext()){ if(in.hasnextdouble()){ double f=in.nextdouble(); test.add(f);} else {in.next();} } catch(ioexception e) { system.err.println("exception during reading: " + e); } } my problem add 66.56,2.1 , 1 doesn't add 3 after "3 or ignores 3-43 , 5-42 can tell me how skip strings , add doubles here? thanks all said 3 ie; "3, 3-43 , 4-42 strings either u read string , split , check number @ " , - or put in space between characters , integers. jvm after compilation tre...
Read more