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To plot all the values of an R data frame, we can use matplot function. This function plots all the values based on the columns of an R data frame and represent them by the column number. For example, if we have five columns in an R data frame then matplot will represent the first column by 1, second column by 2, third column by 3 and so on.Consider the below data frame −Example Live Demoset.seed(555) v1
The proportion of row values can be calculated if we divide each row value with the sum of all values in a particular row. Therefore, the total sum of proportions will be equal to 1. This can be done by dividing the data frame with the row sums and for this purpose we can use the below syntax −Syntaxdata_frame_name/rowSums(data_frame_name)Consider the below data frame −Example Live Demoset.seed(111) x1
Suppose we have a list of sorted unique numbers called nums and an integer k, we have to find the kth missing number from the first element of the given list.So, if the input is like nums = [5, 6, 8, 10, 11], k = 1, then the output will be 9, as 9 is the second (index 1) missing number.To solve this, we will follow these steps −for i in range 1 to size of nums, dodiff := nums[i] - nums[i - 1] - 1if k >= diff, thenk := k - diffotherwise, return nums[i - 1] + k ... Read More
A transparent polygon just represents the border lines and a hollow area; thus, we can only understand the area covered but it becomes a little difficult to understand the scales. Hence, this visualisation technique is not as useful as others that fills the area with a different color. But it could be used if the range of the data is not large.Consider the below data frame −Example Live Demoset.seed(123) x
Suppose we have a singly linked list, we have to check find the value of the kth last node (0-indexed). We have to solve this in single pass.So, if the input is like node = [5, 4, 6, 3, 4, 7], k = 2, then the output will be 3, as The second last (index 3) node has the value of 3.To solve this, we will follow these steps −klast := nodelast := nodefor i in range 0 to k, dolast := next of lastwhile next of last is not null, dolast := next of lastklast := next of klastreturn ... Read More
We might want to create a subset of an R data frame using one or more values of a particular column. For example, suppose we have a data frame df that contain columns C1, C2, C3, C4, and C5 and each of these columns contain values from A to Z. If we want to select rows using values A or B in column C1 then it can be done as df[df$C1=="A"|df$C1=="B",].Consider the below data frame −Exampleset.seed(99) x1
Suppose we have a list of stacks and an integer k. We have to find the maximum possible sum that can be achieved from popping off exactly k elements from any combination of the stacks.So, if the input is like stacks = [[50, -4, -15], [2], [6, 7, 8]], k = 4, then the output will be 39, as we can pop off all 3 elements from the first stack and pop the last element of the last stack to get -15 + -4 + 50 + 8 = 39.To solve this, we will follow these steps −Define a function ... Read More
The contingency table considers the numerical values for two categorical variables. Often, we require contingency table for counts, especially in non-parametric analysis but it is also possible that we want to use means for our analysis. Hence, we can use cast function from reshape package which solves the problem of creating contingency table easily.Consider the below data frame −Example Live Demoset.seed(99) x1
Sometimes the data frame is filled with too many missing values/ NA’s and each column of the data frame contains at least one NA. In this case, we might want to find out how many missing values exists in each of the columns. Therefore, we can use colSums function along with is.na in the following manner: colSums(is.na(df)) #here df refers to data frame name.Consider the below data frame −Example Live Demoset.seed(109) x1
Suppose we have a list of numbers called nums and another number k, we have to find a list of count of distinct numbers in each window of size k.So, if the input is like nums = [2, 2, 3, 3, 4], k = 2, then the output will be [1, 2, 1, 2], as the windows are [2, 2], [2, 3], [3, 3], and [3, 4].To solve this, we will follow these steps −c := make a dictionary of elements in nums and their frequenciesans := a new listfor i in range k to size of nums, doinsert size ... Read More