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Articles on Trending Technologies
Technical articles with clear explanations and examples
How to find the row sums if NA exists in the R data frame?
To find the row sums if NA exists in the R data frame, we can use rowSums function and set the na.rm argument to TRUE and this argument will remove NA values before calculating the row sums.For Example, if we have a data frame called df that contains some NA values then we can find the row sums by using the below command −df$Row_Sums
Read MoreReverse a number using stack in C++
We are given an integer number Num as input. The goal is to find the reverse of the number using stack.Stack:- A stack is a data structure in C++ which stores data in LIFO ( Last in First Out) manner. Major operations of stack are-:Declaration-: stack stck; //stck is now a stack variable.Finding Top using top(). Function stck.top() returns reference of top element in the stckRemoving Top using pop(). Function removes topmost element from the stckAdding element to top using push(). Function stck.push( value ) adds item value in stack. Value should be of type stck.Check if staxk is ...
Read MoreRecursive Programs to find Minimum and Maximum elements of array in C++
We are given an integer array Arr[] as input. The goal is to find maximum and minimum elements among the array using recursive methods.Since we are using recursion, we will traverse the whole array till we reach length=1 then return A[0] which forms the base case. Else compare current element with present minimum or maximum and update its value by recursion for later elements.Let us see various input output scenarios for this −Input − Arr= {12, 67, 99, 76, 32};Output − Maximum in the array :99Explanation − Out of all elements 99 is maximum among them.Input − Arr= {1, 0, -99, 9, 3};Output − Minimum ...
Read MoreHow to add zero before a vector in R?
To add zero before a vector in R, we can simply use rep function and provide the number times we want to have zero in the vector.For Example, if we have a vector called X that contains three values say 1, 2, 3 and we want to add three zeros before this vector then we can use the command as given below −X
Read MoreFill bars in a base R barplot with colors based on frequency.
Suppose we have a vector that contains only frequencies and we want to create a bar chart in base R using these frequencies with color of bars based on frequencies, therefore, we can use barplot function and providing the color of the bars with as shown in the below ExamplesThe function is as follows −heat.colors functionExample 1To fill the bars in a base R barplot with colours based on frequency, use the command given below −Frequency_1
Read MoreWhat is Shift Reduce Parser?
Shift Reduce Parser is a type of Bottom-Up Parser. It generates the Parse Tree from Leaves to the Root. In Shift Reduce Parser, the input string will be reduced to the starting symbol. This reduction can be produced by handling the rightmost derivation in reverse, i.e., from starting symbol to the input string.Shift Reduce Parser requires two Data StructuresInput BufferStackThere are the various steps of Shift Reduce Parsing which are as follows −There are the various steps of Shift Reduce Parsing which are as follows −It uses a stack and an input buffer.Insert $ at the bottom of the stack ...
Read MoreHow to create a circle filled with a color in R?
We can create a circle in R by using draw.circle function of plotrix package and default color of the circle is white. If we want to change the color of a circle then we can use col argument and pass the desired colors.For Example, if we want to create a blue colored circle then we can use the command given below −draw.circle(5, 5, 2, col="blue")Check out the below Example to understand how it works.ExampleTo create a circle filled with a colour, use the command given below −plot(1:10, type="n") OutputIf you execute the above command, it generates the following Output −To ...
Read MoreShow that the following grammar is LR (1)nS → A a |b A c |B c | b B anA → dnB → d
SolutionStep1 − Construct Augment Grammar(0) S′ → S(1) S → A a(2) S → b A c(3) S → B c(4) S → b B a(5) A → d(6) B → dStep2 − Find Closure & goto. Construct a set of LR (1) items. Here all the boxes represent new states.LR (1) Parsing TableSo, the LR (1) Parsing Table has no several entries. Grammar is LR (1).Construction of LR (1) or Canonical LR Parsing TableInput − An Augmented Grammar G’.Output − The Canonical LR (1) Parsing TableMethodFilling the "shift" Entries(s) − Apply Rule (2a) of construction of CLR Parsing Table.Consider ...
Read MoreHow to change a text value in an R data frame?
To change a text value in an R data frame, we can simply use replace function.For Example, if we have a data frame called df that contains a column say Names and one of the names say Raj is misspelled as Raaj then we can replace Raaj with Raj by using the command given below −df$Names
Read MoreConsider the GrammarnS → CCnC → c C | dnConstruct the parsing table for LALR (1) parser.
SolutionStep1 − Construct LR (1) Set of items. First of all, all the LR (1) set of items should be generated.In these states, states I3 and I6 can be merged because they have the same core or first component but a different second component of Look Ahead.Similarly, states I4 and I7 are the same.Similarly, states I8 and I9 are the same.So, I3 and I6 can be combined to make I36.I4 and I7 combined to make I47.I8 and I9 combined to make I89.So, the states will be∴ I3 = goto (I0, c)But I3 , I6 combined to make I36∴ I36 = ...
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