DS with R | Dec 22 - Jan 27 | Samridhi

Discussion in 'Big Data and Analytics' started by Nishant_Singh, Dec 21, 2018.

  1. Nishant_Singh

    Nishant_Singh Well-Known Member
    Staff Member Simplilearn Support

    Joined:
    Aug 1, 2018
    Messages:
    312
    Likes Received:
    109
    #1
  2. _48134

    _48134 Member

    Joined:
    Nov 13, 2018
    Messages:
    2
    Likes Received:
    0
    hi team,

    this is Chandu here..
     
    #2
  3. _48134

    _48134 Member

    Joined:
    Nov 13, 2018
    Messages:
    2
    Likes Received:
    0
    #Assignment -1 : to print 2 table
    # Solution
    i= 1
    while(i < 11)
    {
    paste("2 * ", i," = ",2*i) -> j
    print (j)
    i = i+1
    }
     
    #3
  4. _44674

    _44674 New Member

    Joined:
    Oct 22, 2018
    Messages:
    1
    Likes Received:
    0
    # Assignment 1 - To print multiplication table of 2
    a=c(1:10)
    b=NULL
    for (i in a)
    {
    paste("2 X",i,"=",2*a)->b
    print(b)
    }


    # Assignment 2 - to print the following
    #1111
    # 111
    # 11
    # 1
    lines=c(1:4)
    cols=c(1:4)
    a=NULL
    for (i in lines)
    {
    for(j in cols)
    {
    if (j<i)
    next
    1->a[j]
    b<-as.integer(a)
    b[which(is.na(b))]=0
    }
    print(b)
    a=NULL
    }
     
    #4
  5. _52654

    _52654 New Member

    Joined:
    Dec 19, 2018
    Messages:
    1
    Likes Received:
    0
    #Assignment 1: Print table of 2
    Val1=c(1:10)
    tab1=NULL
    for (i in val1)
    {
    paste("2 X",val1,"=",2*val1)->tab1
    }
    print(tab1)
     
    #5
    Last edited: Jan 4, 2019
  6. _46256

    _46256 Member

    Joined:
    Oct 31, 2018
    Messages:
    5
    Likes Received:
    0
    # Assignment1 - print the table of 2
    # 2 x 1 = 2 ....

    j = 2
    for(i in 1:10)
    {
    paste(j, " x ",i," = ",j*i) -> x
    print(x)
    }
     
    #6
  7. _51728

    _51728 Member

    Joined:
    Dec 12, 2018
    Messages:
    5
    Likes Received:
    0
    #nested loop to print inverted right angle triangle of 1
    rows=1:4
    cols=1:4
    p=1
    for (i in rows)
    {
    for (j in cols)
    {
    ifelse((j<=4 & j>=i), yes = "1", no ="" )->p[j]
    p[j]=as.numeric(p[j])
    j=j+1
    }
    ifelse((i<=4 & i>j), yes = break , no = "1" )->q
    print(p)
    i=i+1
    }
     
    #7
  8. _51728

    _51728 Member

    Joined:
    Dec 12, 2018
    Messages:
    5
    Likes Received:
    0
    #multiplication of 2
    a = 1:10
    #b = 2
    for(i in a)
    {
    readline(prompt = "Please enter number:")->b
    b = as.integer(b)
    if(i<=10)
    x=b*a
    paste(b,"X",a,"=",x)->y[x]
    print(y[x])
    i=i+1
    break
    }
     
    #8
  9. Manish Rawat

    Manish Rawat Member

    Joined:
    Jun 13, 2016
    Messages:
    3
    Likes Received:
    0
    Class2:
    Assignment 1 (Multiplication table of 2)
    a=2
    for (i in c(1:10))
    {
    cat(a," * ",i,"=",a*i,"\n")
    }

    Assignment 2
    rows= 1:4
    cols = 1:4
    for(i in rows)
    {
    for(j in cols)
    {
    if(i>j)
    {
    a=paste(" ",sep="")
    }else
    {
    a=paste(1,sep="")
    }
    cat(a)
    }
    cat("\n")
    }

    xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
    Class3:
    Assignment 3, from mt matrix delete col named wt and vs

    mt<-mtcars
    colnames(mt)
    which(colnames(mt)=='wt')
    which(colnames(mt)=='vs')
    mt[,-c(6,8)]->a
    colnames(a)

    Assignment 4
    interchange the position of column classB and classD in mat

    matrix(data=c(1,10,20,4,6,8),nrow=2, ncol=3)->mat
    colnames(mat)=c("ClassA","ClassB", "ClassC")
    rownames(mat)=c("schoolA","schoolB")
    schoolc=c(20, 10, 45)
    rbind(mat, schoolc)->mat
    ClassD=c(10,4,12)
    cbind(mat,ClassD)->mat
    mat[,c("ClassA","ClassD","ClassC", "ClassB")]

    Manish Rawat
     
    #9
  10. John Paul Dysangco

    Joined:
    Dec 11, 2018
    Messages:
    3
    Likes Received:
    0
    Hi Samridhi,

    Can you please save the class 4 notes from yesterday to the shared Google Drive?

    Thanks,
    JP
     
    #10
  11. _51728

    _51728 Member

    Joined:
    Dec 12, 2018
    Messages:
    5
    Likes Received:
    0
    class 4 notes and assignments not shared yet?
     
    #11
  12. Samridhi Dutta

    Samridhi Dutta Well-Known Member
    Alumni Trainer

    Joined:
    Aug 16, 2017
    Messages:
    250
    Likes Received:
    22
    Done!
     
    #12
  13. _46256

    _46256 Member

    Joined:
    Oct 31, 2018
    Messages:
    5
    Likes Received:
    0
    # Assignment3: From this mt matrix, delete wt and vs columns
    mtcars -> mt
    mt
    # to get index of wt column name
    grep("^wt", colnames(mt))->x
    x
    mt[, -x] -> mt
    View(mt)

    # to get index of wt column name
    grep("^vs", colnames(mt))->x
    x
    mt[, -x] -> mt
    View(mt)



    #Assignment4: Interchange the position of classB and classD
    mat[,c(2,4)] -> mat[,c(4,2)]
    mat

    colnames(mat)[c(2,4)] -> colnames(mat)[c(4,2)]
    mat
     
    #13
  14. _52033

    _52033 Member

    Joined:
    Dec 14, 2018
    Messages:
    2
    Likes Received:
    0
    How to retrieve iris data set. Got accidentally erased
     
    #14
  15. _46256

    _46256 Member

    Joined:
    Oct 31, 2018
    Messages:
    5
    Likes Received:
    0
    # Submission by Ashish R
    # Assignment on DF
    #Use the data-set iris
    View(iris) #iris is a pre-loaded data-set in r
    iris$Sepal.Length
    #Q. Find the average sepal length of Setosa species. Hint: use function "mean"
    #Hint: Following is the mean function
    mean(iris$Sepal.Length, na.rm = T)
    #Note: na.rm = T will remove nas while finding mean

    #Q. Find the different categories of species variable. Hint use "table" function on Species variable
    iris$Species
    table(iris$Species)
    levels(iris$Species)

    #Q. Find which species has the highest Petal Width.
    iris$Species[iris$Petal.Width == max(iris$Petal.Width)]


    #Q. For all the virginica flowers having petal width = 2.0, make their petal length to 5.5
    iris$Petal.Length[iris$Petal.Width == 2.0] = 5.5
    iris$Petal.Length[iris$Petal.Width == 2.0]

    #titanic dataset
    #Q. read the titanic_train file
    titanic_train=read.csv("D:\\Training\\Data Science\\R\\Datasets\\titanic_train.csv")
    head(titanic_train, 10)

    #Q. Find the number of passengers who survived
    sum(titanic_train$Survived)

    #Q. Find the age of Timothy
    nm_Age = grep("Timothy", titanic_train$Name, ignore.case= TRUE)
    nm_Age
    titanic_train$Age[nm_Age]

    View(titanic_train)


    #Q. Find names of passengers having age>35
    titanic_train$Name[titanic_train$Age>35]

    #Q. The age of Henry has been entered incorrect. Please change it to 45.
    nm_Age = grep("Henry", titanic_train$Name, ignore.case= TRUE)
    nm_Age
    titanic_train$Age[nm_Age]
    titanic_train$Age[nm_Age] = 45
    titanic_train$Age[nm_Age]

    #Q. How many NAs are there in Age column. Replace the NAs by the mean age.Following fn will give the mean age:
    # find out NAs inAge column
    sum(is.na(titanic_train$Age))
    m_age = mean(titanic_train$Age,na.rm = TRUE)
    m_age

    #Q. Add another column: Family_Members = 1(Self) + SibSp (gives number of siblings + spouse) + Parch (gives parents + children)
    class(titanic_train)
    ?data.frame
    ?cbind.data.frame
    names(Family_members)
    titanic_train$Name

    cbind(titanic_train, Family_members = factor(1+titanic_train$SibSp+titanic_train$Parch)) -> titanic_train

    View(titanic_train)
     
    #15
  16. _49137

    _49137 Member

    Joined:
    Nov 22, 2018
    Messages:
    3
    Likes Received:
    0
    Hi Guys,

    could you please anyone help me on downloading the projects.???
     
    #16
  17. _52033

    _52033 Member

    Joined:
    Dec 14, 2018
    Messages:
    2
    Likes Received:
    0
    In the lms.simplilearn.com, > the self learning tab >Course Resources> Projects. Here you can download the projects
     
    #17
  18. _52616

    _52616 Member

    Joined:
    Dec 18, 2018
    Messages:
    12
    Likes Received:
    1
    Hello, I'm trying to watch the classes 3 and 4 from "Downloading Records" but they are empty.
     
    #18
  19. _52616

    _52616 Member

    Joined:
    Dec 18, 2018
    Messages:
    12
    Likes Received:
    1
    #submission by Mario Garcia (_52616)
    #Assignment on data-frames

    #Use the data-set iris
    View(iris) #iris is a pre-loaded data-set in r
    iris$Sepal.Length
    #Q. Find the average sepal length of Setosa species. Hint: use function "mean"
    #Hint: Following is the mean function
    mean(iris$Sepal.Length, na.rm = T)#na.rm = T will remove nas while finding mean
    #rta: 5.8433
    #Q. Find the different categories of species variable. Hint use "table" function on Species variable
    table(iris$Species)
    levels(iris$Species)
    ?table
    ?levels
    # levels provides access to the levels attribute of a variable. The first form returns the value of the levels of its argument and the second sets the attribute.
    # table uses the cross-classifying factors to build a contingency table of the counts at each combination of factor levels.

    table(iris$Sepal.Length)
    table(iris$Sepal.Width)
    hist(iris$Sepal.Width)

    #Q. Find which species has the highest Petal Width.
    max_petal_with <- max(iris$Petal.Width)
    iris$Species[iris$Petal.Width == max_petal_with]
    #response: max_petal_with = 2.5
    #response: species "Virginica"

    #Q. For all the virginica flowers having petal width = 2.0, make their petal length to 5.5
    petal_width = 2.0
    iris_species_viginica <- iris[ iris$Species == 'virginica', ]
    iris_species_viginica_petal_width_20 <- iris_species_viginica[ iris$Sepal.Width == 2.0, ]
    iris_species_viginica_petal_width_20$Petal.Length = 5.5


    #titanic dataset
    #Q. read the titanic_train file
    getwd()
    titanic_train = read.csv("titanic_train.csv")
    head(titanic_train, 10)
    View(titanic_train)
    str(titanic_train)

    #Q. Find the number of passengers who survived
    survived <- 1
    titanic_train_survived = titanic_train[ titanic_train$Survived == survived ,]
    count(titanic_train_survived)
    #response: 342
    #Q. Find the age of Timothy
    name = 'Timothy'
    titanic_train_by_name_idx <- grep(name, titanic_train$Name, ignore.case=TRUE)
    titanic_train_by_name_idx
    titanic_train[ titanic_train_by_name_idx, c('PassengerId', 'Name', 'Age') ]
    #response: McCarthy, Mr. Timothy J is 54 years old

    #Q. Find names of passengers having age>35
    age <- 35
    titanic_train_by_age <- titanic_train[ titanic_train$Age > age, ]
    View(titanic_train_by_age)
    titanic_train_by_age$Name
    #response:
    #Q. The age of Henry has been entered incorrect. Please change it to 45.
    name = 'Henry,'
    age = 45
    titanic_train_by_name_idx = grep(name, titanic_train$Name, ignore.case=TRUE)
    titanic_train_by_name_idx
    titanic_train_by_name <- titanic_train[ titanic_train_by_name_idx, ]
    titanic_train_by_name
    titanic_train_by_name$Age <- age
    #Q. How many NAs are there in Age column. Replace the NAs by the mean age.Following fn will give the mean age:
    titanic_train_by_age_idx = is.na( titanic_train$Age )
    titanic_train_by_age_idx
    titanic_train_by_age = titanic_train[ titanic_train_by_age_idx, ]
    count(titanic_train_by_age)
    #response: there are 177

    age_mean <- mean(titanic_train$Age,na.rm = TRUE)
    age_mean
    titanic_train_by_age$Age <- age_mean
    titanic_train_by_age

    #Q. Add another column: Family_Members = 1(Self) +
    # SibSp (gives number of siblings + spouse) +
    # Parch (gives parents + children)

    ?cbind
    # Take a sequence of vector, matrix or data-frame arguments and combine by columns or rows, respectively. These are generic functions with methods for other R classes.
    titanic_train <- cbind( titanic_train, Family_Members = factor( 1 + titanic_train$SibSp + titanic_train$Parch ))
    View(titanic_train )
     
    #19
  20. _52616

    _52616 Member

    Joined:
    Dec 18, 2018
    Messages:
    12
    Likes Received:
    1
    When I answered the "knowledge check", some characters are "?" symbol. How can I get the right character? I think that is a problem of char encoder
     
    #20
  21. _55153

    _55153 Member

    Joined:
    Jan 8, 2019
    Messages:
    2
    Likes Received:
    0
    Hi Samridhi ,
    Could you please my help me on the hypothesis questions which i have on one of the exercise which i found online

    I am trying to solve an hypothesis question which i believe it is similar to students score example related to Ramesh tutor example you explained in the class. I believe i understood the example and i thought i got it :) . But when iam soliving another similar example i have variety of doubts. Hoping to get it resolved . Iam attaching the doc which is having background and questions are highlighted in red color. Iam unable to attach the dataset because of restriction of size and types of files.

    Thanks in advance.
     

    Attached Files:

    • pr.zip
      File size:
      15.5 KB
      Views:
      4
    #21
  22. Samridhi Dutta

    Samridhi Dutta Well-Known Member
    Alumni Trainer

    Joined:
    Aug 16, 2017
    Messages:
    250
    Likes Received:
    22
    Hi, I will need the dataset and the .R file to help you with this. Without comprehending the data, it is difficult to comprehend the problem statement. Can you please share the data-set in a zip file. If it is too large for an upload here, could you please upload on google drive and share the link here.

    Regards,
    Samridhi
     
    #22
    Last edited: Mar 13, 2019
  23. _55153

    _55153 Member

    Joined:
    Jan 8, 2019
    Messages:
    2
    Likes Received:
    0
    #23
  24. Samridhi Dutta

    Samridhi Dutta Well-Known Member
    Alumni Trainer

    Joined:
    Aug 16, 2017
    Messages:
    250
    Likes Received:
    22
    #24
  25. Samridhi Dutta

    Samridhi Dutta Well-Known Member
    Alumni Trainer

    Joined:
    Aug 16, 2017
    Messages:
    250
    Likes Received:
    22
    I am attaching my solution here. I feel there is a flaw in the logic of the code shared. We have to compare the adherence marks of those who certified before / after 1990. We don't have the certification scores in our data. So, we don't have a relation with that. We will not have to create multiple dataframes to divide the adherence scores based on before / after 1990.

    I have shared my perspective to the problem in the attached file. Let me know if there are any questions which need more explanation.

    Regards,
    Samridhi
     

    Attached Files:

    #25
  26. Madhavi_21

    Madhavi_21 Member

    Joined:
    Feb 25, 2019
    Messages:
    4
    Likes Received:
    0
    #Assignment 2 - Vectors
    a = c(1:4)
    b = c(10,20,30, 40)
    c = c(100:110)
    #Q. Perform the following operations on the above vectors
    a + b
    a * b
    a / b
    a %% b
    b+c -> d
    b*c -> e
    c-b -> f
    c/b
    c %/%b
    #Q. Please state your observation on what happens when arithmetic operators are applied on c and b
    #ans: b gets applied repeatedly
    #Q. How many components are there in the vector c
    length(c)
    #ans: : 11
    #Q. Delete the last 5 components of the vector c
    c <- c[-(length(c)-4:length(c))]
    #Q. Strip off the beginning space char from the following character vector
    strings = c(" Astha Ahuja", " Beena Ahuja", " Charu Raheja")
    strings =sub(".? ","",strings)
    #Q. Find all the components of the vector that begin with new (ignore the case)
    Strings = c("New York", "New Mumbai", "Mumbai new")
    #Soln: grep("^new", strings, ignore.case = T)
    strings2 <-grep(pattern = "^New", x=Strings)
    Strings[strings2]
    #Q. Find all the components of the vector that end with the new (ignore the case)
    Strings = c("New York", "New Mumbai", "Mumbai new")
    #Soln: grep("new$", strings, ignore.case = T)
    strings2 <-grep(pattern = "new$", x=Strings)
    Strings[strings2]
    #Q. Replace " ." with space character
    Strings = c("Divya.Ahuja", "Mukul.Khanna")
    Strings = gsub("\\.","\\s ",Strings)
    Strings
     
    #26
  27. Samridhi Dutta

    Samridhi Dutta Well-Known Member
    Alumni Trainer

    Joined:
    Aug 16, 2017
    Messages:
    250
    Likes Received:
    22
    Hi Madhavi,
    You have posted your solution in the wrong thread :)
    This is not the thread of your batch, this is an older thread.

    Regards,
    Samridhi
     
    #27

Share This Page