Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Articles on Trending Technologies
Technical articles with clear explanations and examples
How to change the resolution of a plot in base R?
In base R, we can save a plot as a png and pass the resolution in the same stage. The procedure to do this is creating the png image with resolution with res argument then creating the plot and using dev.off() to create the file. Check out the below examples to understand how it works.Example1> png(file="example1.png",res=100) > plot(1:10) > dev.off()Output:Example2> png(file="example2.png",res=200) > plot(1:10) > dev.off()Output
Read MoreHow to change legend values in a bar plot created by using ggplot2 in R?
How to change legend values in a bar plot created by using ggplot2 in R?By default, the legend values are taken as the different levels of the categorical variable for which a bar plot is created using ggplot2 package and if we want to change those values then scale_color_manual function of the ggplot2 package can be used where we need to pass the values for color and labels for legend values.ExampleConsider the below data frame:> set.seed(1214) > x1 y1 df1 df1Output x1 y1 1 B 4 2 B 5 3 C 5 4 ...
Read MoreHow to find the less than probability using normal distribution in R?
The less than probability using normal distribution is the cumulative probability which can be found by using cumulative distribution function of the normal distribution. In R, we have pnorm function that directly calculates the less than probability for a normally distributed random variable that takes Z score, mean and standard deviation.Examplespnorm(0.95,1,0) pnorm(0.95,0,1) pnorm(0.10,0,1) pnorm(0.10,1,5) pnorm(0.10,1,50) pnorm(0.10,25,50) pnorm(0.12,25,50) pnorm(0.12,2,0.004) pnorm(0.12,2,0.5) pnorm(1,2,0.5) pnorm(12,20,3) pnorm(12,12,3) pnorm(12,15,3) pnorm(200,15,3) pnorm(200,201,3) pnorm(200,201,5) pnorm(20,25,5)Output[1] 0 [1] 0.8289439 [1] 0.5398278 [1] 0.4285763 [1] 0.4928194 [1] 0.309242 [1] 0.309383 [1] 0 [1] 8.495668e-05 [1] 0.02275013 [1] 0.003830381 [1] 0.5 [1] 0.1586553 [1] 1 [1] 0.3694413 [1] 0.4207403 [1] 0.1586553
Read MoreWhat is the use of type = "h" in base R for plotting a graph?
The type = "h" is a graphing argument in base R which is generally used inside a plot function. It helps to generate the vertical lines in the R environment instead of points. For example, if we want to plot values from 1 to 10 then type = "h" will plot the vertical lines starting from X-axis and the upper end of the lines will represent the actual value.Example1> plot(1:10,type="h")Output:Example2> plot(rnorm(10),type="h")Output:
Read MoreHow to create different Y-axis for group levels using ggplot2 in R?
If we have a categorical variable or a group variable then we might want to create a line chart for each of the categories or levels, this will help us to understand the range of multiple levels in a single plot. For this purpose, we can use facet_grid function of ggplot2 package as shown in the below example.ExampleConsider the below data frame:> x y df dfOutput x y 1 C -1.55668689 2 A 2.41399136 3 D -0.78520253 4 A -0.43092594 5 C 1.94379390 6 A ...
Read MoreProgram to find cost to remove consecutive duplicate characters with costs in C++?
Suppose we have a string with lowercase letters and we also have a list of non-negative values called costs, the string and the list have the same length. We can delete character s[i] for cost costs[i], and then both s[i] and costs[i] is removed. We have to find the minimum cost to delete all consecutively repeating characters.So, if the input is like s = "xxyyx" nums = [2, 3, 10, 4, 6], then the output will be 6, as we can delete s[0] and s[3] for a total cost of 2 + 4 = 6.To solve this, we will follow ...
Read MoreHow to convert diagonal elements of a matrix in R into missing values?
First thing we need to understand is diagonal elements are useful only if we have a square matrix, otherwise it would not make sense to set diagonal elements, this is known to almost all mathematicians but some freshman might get confused because we can create diagonal in a non-square matrix which should not be called a diagonal. In R, we can set the diagonal elements of a matrix to missing values/NA by using diag function.Example1> M1 M1Output [, 1] [, 2] [, 3] [, 4] [1, ] 1 5 9 13 [2, ] 2 6 ...
Read MoreHow to draw a circle in R?
There is no direct function in R to draw a circle but we can make use of plotrix package for this purpose. The plotrix package has a function called draw.cirlce which is can be used to draw a circle but we first need to draw a plot in base R then pass the correct arguments in draw.circle. The first and second arguments of draw.circle takes x and y coordinates, and the third one is for radius, hence these should be properly chosen based on the chart in base R.Loading plotrix package:> library(plotrix)Creating different circles using draw.circle:Example> plot(1:10, type="n") > draw.circle(2, ...
Read MoreHow to create a new column in an R data frame based on some condition of another column?
Sometimes we want to change a column or create a new by using other columns of a data frame in R, this is mostly required when we want to create a categorical column but it can be done for numerical columns as well. For example, we might want to create a column based on salary for which if salaries are greater than the salary in another column then adding those salaries otherwise taking the difference between them. This will help us to understand whether the salaries in two columns are equivalent, lesser, or greater. In R, we can use transform ...
Read MoreCount number of pairs (A <= N, B <= N) such that gcd (A , B) is B in C++
We are given an input N. The goal is to find all pairs of A, B such that 1
Read More