grayskripko

https://github.com/pytorch/pytorch/issues/958#issuecomment-309752126

grayskripko

# -*- coding:utf8 -*-
# !/usr/bin/env python

from flask import Flask, request, session, make_response
from flask_pymongo import PyMongo
from utils.server import *
from utils.data import *

import pandas as pd
import numpy as np

grayskripko

# when you need to use tidyselect in a mutate function
# https://stackoverflow.com/questions/48353331/row-wise-operations-select-helpers-and-the-mutate-function-in-dplyr
tbl %>% mutate(a = select(., contains("abc")))

# based on https://rpubs.com/wch/200398
mtcars %>% purrrlyr::by_row(~any(is.na(.)), .collate = "rows", .to = "has_missing")

tibble(a=c(1, NA, 3), b=c(NA, 2, NA), c=c(NA, 5, 6)) %>% 
  mutate(pmap_int(., function(...) sum(lift_ld(is.na)(...))))

grayskripko

xx <- "b"

data.frame(a=1:3, b=c(2, NA, 5)) %>% filter(!is.na(get(xx)))

data.frame(a=1:3, b=c(2, NA, 5)) %>% filter(!is.na(!!as.name(xx)))

grayskripko

x <- data.frame(a=1, b=2)

x %>% rename_at(vars(names(.)), ~letters[3:4])

x %>% rename_all(~letters[3:4])

x %>% rename_all(funs(str_c('prefix_', .)))

x %>% rename_at(vars(-starts_with("a")), ~str_c(., "_b"))  # approx.

grayskripko

# https://www.enchufa2.es/archives/programming-with-dplyr-by-using-dplyr.html

# 1. reminder
starwars_mean <- function(var) {
  var <- enquo(var)
  starwars %>% group_by(!!var)
}
starwars_mean(homeworld)

# 2. parsing a string inside

grayskripko

``` r
library(dplyr)

x <- tibble(a=c(1, 2, 2, 3)) 

x %>% group_by(a) %>% summarise(n())
#> # A tibble: 3 x 2
#>       a `n()`
#>   <dbl> <int>
#> 1     1     1

grayskripko

pacman::p_load(tidyverse, xgboost)

# in xgboost: "cb" for "callback", "bst" for "booster"
cb_best_model <- function(print_improvements, save_cv_models) {
  
  # callback is the main function that will be executed on every iteration
  callback <- function(env = parent.frame(), finalize = FALSE) {
    if (is.null(env$basket) || is.null(env$bst_folds))
      stop("'cb_best_model' callback requires 'basket' and 'bst_folds' lists 
           in its calling frame")

grayskripko

library(tidyverse)

# case 1
forest %>% map(predictions) %>% map(assess) %>% transpose() %>% 
    map(~imap(., ~rename(.x, !!.y := value))) 
# > ... works

forest %>% map(predictions) %>% map(assess) %>% transpose() %>% 
    map(~imap(~rename(.x, !!.y := value)))
# > Error in as_mapper(.f, ...) : argument ".f" is missing, with no default

grayskripko

```
... package ‘parsnip’ successfully unpacked and MD5 sums checked

The downloaded binary packages are in
	C:\Users\Gray\AppData\Local\Temp\Rtmps7lBHE\downloaded_packages

parsnip installed
Failed to install/load:
parsnip
```