r - Looping through elements of a list and then appending to a new list -


i've been trying write code allow me loop through items of list, each of vector of numeric values. elements of vector meets criterion, want append numbers new list contains vector of numeric values.

my dataset structured following:

col1 col2 col3 .... col29 -11   -10  -9  ....   15 -13   -12  -11 ....   14

i've tried following code far:

new_list <- list() for(i in 1:length(time_list)) {   for(j in 1:length(time_list[[i]]) {     if(!is.na(time_list[[i]][j]) & time_list[[i]][j] >= 0) {       # stuck here, code i've run gives me error.     }   } }

i want list that's structured pretty same original, keeping numbers greater or equal 0.

any appreciated.

i call data df 

df <- structure(list(time_1 = -13l, time_2 = -12l, time_3 = -11l, time_4 = -10l,          time_5 = -9l, time_6 = -8l, time_7 = -7l, time_8 = -6l, time_9 = -5l,          time_10 = -4l, time_11 = -3l, time_12 = -2l, time_13 = -1l, time_14 = 0l,          time_15 = 1l))  is.pos <- function(x){   (!is.na(x)) & (x >= 0) }

the function check whether dealing positive number , return either true or false. we'll use indexing:

is.pos(df) # time_1  time_2  time_3  time_4  time_5  time_6  time_7  time_8  time_9 time_10  # false   false   false   false   false   false   false   false   false   false  # time_11 time_12 time_13 time_14 time_15  # false   false   false    true    true   df[is.pos(df)] # $time_14 # [1] 0 #  # $time_15 # [1] 1

Comments

Post a Comment

Popular posts from this blog

android - InAppBilling registering BroadcastReceiver in AndroidManifest -

i'm implementing inapp billing in android app. works well, however, i'm trying decouple broadcast receiver activity manifest. suggestion in android's trivialdrive sample: // important: dynamically register broadcast messages updated purchases. // register receiver here instead of <receiver> in manifest // because call getpurchases() @ startup, therefore can ignore // broadcasts sent while app isn't running. // note: registering listener in activity bad idea, done here // because sample. regardless, receiver must registered after // iabhelper setup, before first call getpurchases(). currently there's class extends broadcastreceiver : public class iabbroadcastreceiver extends broadcastreceiver { /** * intent action receiver should filter for. */ public static final string action = "com.android.vending.billing.purchases_updated"; private final iabbroadcastlistener mlistener; public iabbroadcastreceiver(iabbroadcastlistener listener) { m...
Read more

python Tkinter Capturing keyboard events save as one single string -

is possible store keyboard events 1 string? code below stores 1 char , prints it. card reader or bar code reader, contains collection of character/ string not 1 character @ time. goal save char pressed text variable. from tkinter import * root = tk() def key(event): text= event.char text+= event.char print ("pressed", text) def callback(event): frame.focus_set() print ("clicked at", event.x, event.y) frame = frame(root, width=100, height=100) frame.bind("<key>", key) frame.bind("<button-1>", callback) frame.pack() root.mainloop() currently, creating text variable , everytime key() function gets called, , text stores last character typed. you can define text module level variable , , use module level text inside key function - text = '' def key(event): global text text+= event.char print("pressed", text)
Read more

sql server - Why does Linq-to-SQL add unnecessary COUNT()? -

here tables: create table customer ( cid int primary key, name varchar(32) ) create table ord ( oid int primary key, cid int foreign key references customer, address varchar(20) ) here's linq-to-sql statement: var aaa = c in db.customer select new { c, o = c.ord.tolist() }; and here's inexplicable query generated linq-to-sql: select [t0].[cid] [cid], [t0].[name] [name], [t1].[oid] [oid], [t1].[cid] [cid2], [t1].[address] [address], (select count(*) [dbo].[ord] [t2] [t2].[cid] = [t0].[cid]) [value] [dbo].[customer] [t0] left outer join [dbo].[ord] [t1] on [t1].[cid] = [t0].[cid] order [t0].[cid], [t1].[oid] i want understand how rid of count(*) part. it's entirely uncalled for! linq needs count(*) in order determine number of entries returned o = c.ord.tolist() .
Read more