[For this exercise, showtime write downward your answer, without using R. Then, cheque your reply using R.]
Answers to the exercises are available here.
Exercise 1
Create a business office that given a information frame as well as a vector, volition add together a the vector (if the vector length tally amongst the rows pose out of the information frame)
as a novel variable to the information frame.
as a novel variable to the information frame.
Exercise 2
Consider a information frame df:
Id=c(1:10)
Age=c(14,12,15,10,23,21,41,56,78,12)
Sex=c('F','M','M','F','M','F','M','M','F','M')
Code=letters[1:10]
df=data.frame(Id,Age,Sex,Code) Create a business office that, given a information frame as well as 2 indexes, exchanges 2 values of the Code variable amongst each other.
For example, if the index is 1 as well as 3, you lot assign:
For example, if the index is 1 as well as 3, you lot assign:
df[1,'Code']=df[3,'Code']
df[3,'Code']=df[1,'Code'] Exercise 3
Consider 2 variables x,y as well as a information frame df:
x,y integerA=c(1:10)
B=seq(100,10,-10)
H=seq(-200,-50,along.with=B)
df=data.frame(A,B,H) Create a business office that given a information frame df calculate a novel variable ‘SUM_x_y'(If x=2 as well as y=3, thus the novel variable volition travel ‘SUM_2_3’,
if x=4 as well as y=10, thus the novel variable volition travel ‘SUM_4_10’),such that for each row ‘i’ is equal to:
if x=4 as well as y=10, thus the novel variable volition travel ‘SUM_4_10’),such that for each row ‘i’ is equal to:
sum(x*df[1:i,1])+sum(y*df[1:i,2]) Exercise 4
Create a business office that given a numeric vector, variety this inwards ascending lodge as well as duplicate it past times two.
Exercise 5
Create a business office that given a vector alpha numeric, proceed exclusively the numbers as well as utilize the business office created on job 4.
For example, if the input is a vector
For example, if the input is a vector
w="a" "v" "7" "4" "q" , the business office volition return w=8 14. Exercise 6
Create a business office that given a string
return a matrix
ST='NAME: Maria /COUNTRY:uruguay /EMAIL: mariaUY@gmail.com'return a matrix
[,1] [,2]
[1,] "NAME" " Maria "
[2,] "COUNTRY" "uruguay "
[3,] "EMAIL" " mariaUY@gmail.com" Exercise 7
Consider a vector:
ST=c('NAME:Maria /COUNTRY:uruguay /EMAIL:mariaUY@gmail.com','NAME:Paul/COUNTRY:UK /EMAIL:PaulUK@gmail.com',
'NAME:Jhon /COUNTRY:USA /EMAIL:JhonUSA@gmail.com','NAME:Carlos /COUNTRY:Spain /EMAIL:CarlosSP@gmail.com') Create a business office that given a vector string ST provide a matrix:
[,1] [,2] [,3] [,4] [,5]
[1,] "NAME" "Maria " "Paul" "Jhon " "Carlos "
[2,] "COUNTRY" "uruguay " "UK " "USA " "Spain "
[3,] "EMAIL" "mariaUY@gmail.com" "PaulUK@gmail.com" "JhonUSA@gmail.com" "CarlosSP@gmail.com" Exercise 8
Create a business office that given a numeric vector X returns the digits 0 to nine that are non inwards X. If
the business office return
X=0 2 4 8 the business office return
1 3 v vi seven 9 Exercise 9
Create a business office that given 2 strings (one give-and-take each), cheque if i is an anagram of another.
Exercise 10
Create a business office that given i word, provide the seat of word’s letters on
For example, if the give-and-take is ‘abc’, the business office volition provide 1 2 3.
Create a business office that given i word, provide the seat of word’s letters on
letters vector.For example, if the give-and-take is ‘abc’, the business office volition provide 1 2 3.
Want to practise functions a fleck more? We accept to a greater extent than job sets on this topic here.
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Below are the solutions to these exercises.
#################### # # # Exercise 1 # # # #################### # Create a business office that given a information frame as well as a vector, volition add together a the vector (if the vector length tally amongst the rows pose out of the information frame) # equally a novel variable to the information frame. Id=rep(c(1,2,3,4),each=3) Letter=rep(letters[1:3],4) x=seq(1,43,along.with=Id) y=seq(-20,0,along.with=Id) M=data.frame(Id,Letter,x,y) ADD_COL=function(M,v) { if(nrow(M)==length(v)) M=cbind(M,v) return(M) } z=seq(1,100,along.with=Id) M=ADD_COL(M,z) u=c(1:10) M=ADD_COL(M,u) w=seq(0,20,along.with=Id) M=ADD_COL(M,w) M
## Id Letter x y v v ## 1 1 a 1.000000 -20.000000 1 0.000000 ## 2 1 b 4.818182 -18.181818 10 1.818182 ## 3 1 c 8.636364 -16.363636 xix 3.636364 ## 4 2 a 12.454545 -14.545455 28 5.454545 ## v 2 b 16.272727 -12.727273 37 7.272727 ## vi 2 c 20.090909 -10.909091 46 9.090909 ## seven 3 a 23.909091 -9.090909 55 10.909091 ## 8 3 b 27.727273 -7.272727 64 12.727273 ## nine 3 c 31.545455 -5.454545 73 14.545455 ## 10 4 a 35.363636 -3.636364 82 16.363636 ## xi 4 b 39.181818 -1.818182 91 18.181818 ## 12 4 c 43.000000 0.000000 100 20.000000
#################### # # # Exercise 2 # # # #################### #Consider a information frame df: Id=c(1:10) Age=c(14,12,15,10,23,21,41,56,78,12) Sex=c('F','M','M','F','M','F','M','M','F','M') Code=letters[1:10] df=data.frame(Id,Age,Sex,Code) #Create a business office that, given a information frame as well as 2 indexes, exchanges 2 values of the Code variable amongst each other. #For example, if the index is 1 as well as 3, you lot assign:#df[1,'Code']=df[3,'Code'] #df[3,'Code']=df[1,'Code'] change=function(df,a,b) { aux=df[a,'Code'] df[a,'Code']=df[b,'Code'] df[b,'Code']=aux return(df) } df=change(df,1,3) df=change(df,7,2) df=change(df,5,10) df
## Id Age Sex Code ## 1 1 xiv F c ## 2 2 12 chiliad g ## 3 3 xv chiliad a ## 4 4 10 F d ## v v 23 chiliad j ## vi vi 21 F f ## seven seven 41 chiliad b ## 8 8 56 chiliad h ## nine nine 78 F i ## 10 10 12 chiliad e
#################### # # # Exercise 3 # # # #################### # Consider 2 variables x,y as well as a information frame df: # x,y integer # A=c(1:10) # B=seq(100,10,-10) # H=seq(-200,-50,along.with=B) # df=data.frame(A,B,H) # Create a business office that given a information frame df calculate a novel variable 'SUM_x_y'(If x=2 as well as y=3, thus the novel variable volition travel 'SUM_2_3', # if x=4 as well as y=10, thus the novel variable volition travel 'SUM_4_10'),such that for each row 'i' is: # sum(x*df[1:i,1])+sum(y*df[1:i,2]) A=c(1:10) B=seq(100,10,-10) H=seq(-200,-50,along.with=B) df=data.frame(A,B,H) NEWDF=function(df,x,y) { for (i in 1:nrow(df)) df[i,4]=sum(x*df[1:i,1])+sum(y*df[1:i,2]) names(df)[4]=paste('SUM',x,y,sep='_') df } NEWDF(df,3,6)
## Influenza A virus subtype H5N1 B H SUM_3_6 ## 1 1 100 -200.00000 603 ## 2 2 ninety -183.33333 1149 ## 3 3 fourscore -166.66667 1638 ## 4 4 seventy -150.00000 2070 ## v v threescore -133.33333 2445 ## vi vi l -116.66667 2763 ## seven seven xl -100.00000 3024 ## 8 8 thirty -83.33333 3228 ## nine nine xx -66.66667 3375 ## 10 10 10 -50.00000 3465
NEWDF(df,7,5)
## Influenza A virus subtype H5N1 B H SUM_7_5 ## 1 1 100 -200.00000 507 ## 2 2 ninety -183.33333 971 ## 3 3 fourscore -166.66667 1392 ## 4 4 seventy -150.00000 1770 ## v v threescore -133.33333 2105 ## vi vi l -116.66667 2397 ## seven seven xl -100.00000 2646 ## 8 8 thirty -83.33333 2852 ## nine nine xx -66.66667 3015 ## 10 10 10 -50.00000 3135
#################### # # # Exercise 4 # # # #################### #Create a business office that given a numeric vector, variety this inwards ascending lodge as well as duplicate it past times two. FUNVector1=function(v) { v=sort(v)*2 return(v) } v=c(2,4,1,7,3,2,7,9) FUNVector1(v)
## [1] 2 4 4 vi 8 xiv 14 eighteen
#################### # # # Exercise v # # # #################### # Create a business office that given a vector alpha numeric, proceed exclusively the numbers, as well as utilize the business office created on job 4. # For example, if the input is a vector <code>w="a" "v" "7" "4" "q"</code> , the business office volition provide <code>w=8 14</code>. FUNVector2=function(w) { w=as.numeric(w[-which(w %in% letters)]) w w=FUNVector1(w) return(w) } a=c('a','v',4,7,'q') a=FUNVector2(a) a
## [1] 8 xiv
b=c(letters[1:23],10:1,letters[24:26],11:22) b=FUNVector2(b) b
## [1] 2 4 vi 8 10 12 xiv sixteen eighteen xx 22 24 26 28 thirty 32 34 36 38 xl 42 44
#################### # # # Exercise vi # # # #################### # Create a business office that given a string # ST='NAME: Maria /COUNTRY:uruguay /EMAIL: mariaUY@gmail.com' # provide a data.frame # [,1] [,2] # [1,] "NAME" " Maria " # [2,] "COUNTRY" "uruguay " # [3,] "EMAIL" " mariaUY@gmail.com" # ST='NAME: Maria /COUNTRY:uruguay /EMAIL: mariaUY@gmail.com' DF=function(ST) { A=unlist(strsplit(ST,'/')) M=rbind(unlist(strsplit(A[1],':')),unlist(strsplit(A[2],':')),unlist(strsplit(A[3],':'))) return(M) } M=DF(ST) M
## [,1] [,2] ## [1,] "NAME" " Maria " ## [2,] "COUNTRY" "uruguay " ## [3,] "EMAIL" " mariaUY@gmail.com"
#################### # # # Exercise seven # # # #################### # Consider a vector: ST=c('NAME:Maria /COUNTRY:uruguay /EMAIL:mariaUY@gmail.com','NAME:Paul/COUNTRY:UK /EMAIL:PaulUK@gmail.com','NAME:Jhon /COUNTRY:USA /EMAIL:JhonUSA@gmail.com','NAME:Carlos /COUNTRY:Spain /EMAIL:CarlosSP@gmail.com') # Create a business office that given a vector string ST provide a matrix: # [,1] [,2] [,3] [,4] [,5] # [1,] "NAME" "Maria " "Paul" "Jhon " "Carlos " # [2,] "COUNTRY" "uruguay " "UK " "USA " "Spain " # [3,] "EMAIL" "mariaUY@gmail.com" "PaulUK@gmail.com" "JhonUSA@gmail.com" "CarlosSP@gmail.com" ST=c('NAME:Maria /COUNTRY:uruguay /EMAIL:mariaUY@gmail.com','NAME:Paul/COUNTRY:UK /EMAIL:PaulUK@gmail.com','NAME:Jhon /COUNTRY:USA /EMAIL:JhonUSA@gmail.com', 'NAME:Carlos /COUNTRY:Spain /EMAIL:CarlosSP@gmail.com') DF2=function(V) { M=DF(V[1]) for (i in 2:length(V)) M=cbind(M,DF(V[i])[,2]) return(M) } DF2(ST)
## [,1] [,2] [,3] [,4] ## [1,] "NAME" "Maria " "Paul" "Jhon " ## [2,] "COUNTRY" "uruguay " "UK " "USA " ## [3,] "EMAIL" "mariaUY@gmail.com" "PaulUK@gmail.com" "JhonUSA@gmail.com" ## [,5] ## [1,] "Carlos " ## [2,] "Spain " ## [3,] "CarlosSP@gmail.com"
#################### # # # Exercise 8 # # # #################### #Create a business office that given a numeric vector X returns the digits 0 to nine that are non inwards X DIGITS=function(X) { b=0:9 Y=b[!b%in%a] return(Y) } a=c(1,5,3,8) DIGITS(a)
## [1] 0 2 4 vi seven nine
#################### # # # Exercise nine # # # #################### #Create a business office that given 2 strings, cheque if i is an anagram of another. library('stringr')
library('stringi')
ANAGRAM=function(a,b) { x=unlist(stri_extract_all(a, regex=c('\\p{L}'))) y=unlist(stri_extract_all(b, regex=c('\\p{L}'))) if (length(x)==length(y)) {cond=unique(x%in%y==y%in%x) cat('anagram:',ifelse(length(x)==length(y) & length(cond)==1,ifelse(cond==TRUE,TRUE,FALSE),FALSE)) } if (length(x)!=length(y)) cat('anagram: FALSE') } a='serpent' b='present' ANAGRAM(a,b)
## anagram: TRUE
x='married' y='admirer' ANAGRAM(x,y)
## anagram: TRUE
x='Deduction' y='Discounted' ANAGRAM(x,y)
## anagram: FALSE
#################### # # # Exercise 10 # # # #################### #Create a business office that given i word, provide the seat of word's letters on letters vector. ORDERWORD=function(a) { x=unlist(stri_extract_all(a, regex=c('\\p{L}'))) POSITION=which(letters%in%x) return(POSITION) } a='hello' ORDERWORD(a)
## [1] v 8 12 15
Source:
http://www.r-exercises.com/2016/12/05/functions-exercises-vol-2/ http://www.r-exercises.com/2016/12/05/functions-vol-2-solutions/