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Articles on Trending Technologies
Technical articles with clear explanations and examples
How to find the proportion using normal distribution in R?
To find the proportion using normal distribution in R, we can use pnorm function where we can provide the mean and standard deviation of population along with sample, also the tail position can be set by using lower.tail argument to TRUE or FALSE. Check out the below examples to understand how it can be done.Example 1Finding the proportion of values above 55 when sample mean is 50 and standard deviation is 8 −pnorm(55, mean=50, sd=8, lower.tail=FALSE)Output[1] 0.2659855Example 2Finding the proportion of values above 60 when sample mean is 50 and standard deviation is 8 −pnorm(60, mean=50, sd=8, lower.tail=FALSE)Output[1] 0.1056498Example 3Finding ...
Read MoreHow to check if a character column only contains alphabets in R data frame?
To check if a character column only contains alphabets in R data frame, we can follow the below steps −First of all, create a data frame with a character column.Then, use grepl function to check if all the values in the column contains only alphabets.Example 1Let's create a data frame as shown below −x
Read MoreHow to create a subset of an R data frame based on multiple columns?
To create a subset of an R data frame based on multiple columns, we can follow the below steps −First of all, create a data frame.Then, use single square brackets to subset the data frame based on multiple columns.Create the data frameLet's create a data frame as shown below −x1
Read MoreGolang Program to Read the Contents of a File
pre.prettyprint{width:99%!important;} a.demo{top:12px!important; float:right!important;}To read the contents of a file, we can take following steps −We can create a file called test.txt.Clean-up using defer statement.Write the contents of string.Call ReadFile() method to read the file.ReadFile reads the file named by filename and returns the contents.Print the content of the file.Examplepackage main import ( "fmt" "io/ioutil" "log" "os" ) func CreateFile() { file, err := os.Create("test.txt") if err != nil { log.Fatalf("failed creating file: %s", err) } defer file.Close() _, err = file.WriteString("Welcome to Tutorials Point") if err != ...
Read MoreHow to extract the p-value from t test in R?
To extract the p-value from t test in R, we can follow the below steps −First of all, create a data frame with numerical column or a numerical vector.Then, use t.test function to perform the test and put $p.value at the end to extract the p-value from the test output.Example1Create the data frameLet's create a data frame as shown below −x
Read MoreHow to add regression residuals to data frame in R?
To add regression residuals to data frame in R, we can follow the below steps −First of all, create a data frame.Then, use lm function to create the regression model and find the residuals using resid function and adding them to the data frame with $ operator.Create the data frameLet's create a data frame as shown below −x
Read MoreWhat does # mean in Lua programming?
The unary operator # is known as the Length operator in Lua. It is used almost everywhere in Lua. By everywhere, I meant that anywhere we would require to calculate the length of the any string or can also be used in tables also, but when it comes to table, it is generally not preferred to use the # operator as it doesn’t calculate the number of elements present inside the table.Let’s explore different examples of the length operator to understand how we can make use of it.ExampleConsider the example shown below −print(#"abcdefg") print(#{"a", "b", "c", 77})Output7 4In the above ...
Read MoreWhat does operator ~= mean in Lua?
The ~= symbol or operator in Lua is known as the not-equal to operator. In many programming languages you might have seen the symbol != which is also known as the not equals operator.Let’s consider a few examples where we can make use of the not equals operator.ExampleConsider the examples shown below −a = 2 b = 3 print(a ~= b)OutputtrueExamplet1 = {4,2,3} t2 = {2,3,4} print(t1 ~= t2)Outputtrue
Read MoreWhat is the difference between pairs() vs. ipairs() in Lua?
In Lua, we make use of both the pairs() and ipairs() function when we want to iterate over a given table with the for loop. Both these functions return key-value pairs where the key is the index of the element and the value is the element stored at that index table.While both of them have some similarities, it is also good to know that they have some very notable differences that we should be aware of.The first difference between the pairs() and ipairs() function is that the pairs() function doesn’t maintain the key order whereas the ipairs() function surely does.ExampleConsider ...
Read MoreWhy do Lua arrays (tables) start at 1 instead of 0?
Yes, the arrays in Lua start with index 1 as the first index and not index 0 as you might have seen in most of the programming languages.ExampleConsider the example shown below −arr = {10, 11, 12, 13, 14} print(arr[0]) print(arr[1])In the above example, we are printing the values at indices 0 and 1, and by default, the value at the 0 index will be nil, as in Lua, the arrays start indexing from 1, not 0.Outputnil 10So, now we know that the arrays are 1-index based not 0-index based. But, wait, why 1-index and 0-index?Actually, there have been several ...
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