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To create bar plot with positive and negative values, we can make use of ggplot function.For example, if we have a data frame called df that contains a categorical column say C and a numerical column Num which has some positive and some negative values then the bar plot for this data can be created by using the below command −ggplot(df,aes(C,Num))+geom_bar(stat="identity")ExampleFollowing snippet creates a sample data frame −Category
To find the degrees of freedom of residual from a regression model, we can use the function df.residual along with the model object.For example, if we have a regression model stored in an object called Model then the degrees of freedom of residual for the same model can be found by using the command mentioned below −df.residual(Model)Example 1Following snippet creates a sample data frame −x1
To find the power of t test, we can use pwr.t.test function of pwr package where we can pass the arguments for type of the test such as one sample or two sample, alternative hypothesis such as one-sided or two-sided, significance level, difference for two samples, and the sample size.Check out the below examples to understand how it works.Example 1To find the power of t test in R, use the code given below −library("pwr") pwr.t.test(n=100, d=1, sig.level=0.05, type="two.sample", alternative="two.sided")If you execute the above given code, it generates the following output for the two-sample t test power calculation − n = ... Read More
To combine two data frames by filling NA in empty places, we can use rbind_fill function of plyr package.For example, if we have two data frames say DF1 and DF2 that have some common and some uncommon columns then we can combine them by using the below given command −rbind.fill(DF1,DF2)ExampleFollowing snippet creates a sample data frame −df1
To decrease the width of bars for plotly bar chart, we can use layout function and set the autosize argument to FALSE.For example, if we have a data frame called that contains a categorical column C and a numerical column Count then bar chart with decreased width of the bars can be created by using the below command −plot_ly(df,x=x,y=y,type="bar")%>%layout(autosize=F)ExampleFollowing snippet creates a sample data frame −x
To convert a table into matrix in R, we can use apply function with as.matrix.noquote function.For example, if we have a table called TABLE then we can convert it into a matrix by using the command given below −apply(as.matrix.noquote(TABLE),2,as.numeric)Example 1Following snippet creates a dataframe −x1
While generating three address codes for the given expression, it can specify the address of the Label in goto statements. It is very difficult to assign locations of these label statements in one pass so, two passes are used. In the first pass, it can leave these addresses unspecified & in the next pass, and it can fill these addresses. Therefore filling of incomplete transformation is called Backpatching.One-pass code generation using backpatchingBackpatching can be used to generate a program for boolean expressions and the flow of control statements in one pass. In this, synthesized attributes truelist and falselist of non-terminal ... Read More
Control statements are the statements that change the flow of execution of statements.Consider the GrammarS → if E then S1 |if E then S1 else S2 |while E do S1In this grammar, E is the Boolean expression depending upon which S1 or S2 will be executed.Following representation shows the order of execution of an instruction of if-then, ifthen-else, & while do.𝐒 → 𝐢𝐟 𝐄 𝐭𝐡𝐞𝐧 𝐒𝟏E.CODE & S.CODE are a sequence of statements which generate three address code.E.TRUE is the label to which control flow if E is true.E.FALSE is the label to which ... Read More
Boolean means True or False. It can also be represented by 1 or 0.Boolean Expression is the expression that returns true or false. Boolean Expression can be represented in two ways−Conditional ExpressionsFor example, If a > b{ cout Y)A = B + CSolution(1) If A < B goto(4)(2) If X > Y goto(4)(3) goto(6)(4) T = B + C(5) A = TExample3− Write three address code for a > b 𝐀𝐍𝐃 c < d 𝐀𝐍𝐃 e < f.Solution(1) If a > b goto(4)(2) t1 = 0(3) goto(5)(4) t1 = 1(5) If c < d goto(8)(6) t2 = 0(7) goto(9)(8) t2 = 1(9) If e < f goto(12)(10) t3 = 0(11) goto(13)(12) t3 = 1(13) t4 = t1 𝐀𝐍𝐃 t2(14) t5 = t4 𝐀𝐍𝐃 t3
Control statements are the statements that change the flow of execution of statements. For example, If, If-else, Switch-Case, while-do statements. In programming languages, Boolean expressions are used toAlter the flow of control− Boolean expressions are used as conditional expressions in a statement that alter the flow of control. The value of such Boolean expression is implicit in a position reached in a program. For example, if (E) S, the expression E should be true if statement S is reached.Compute logical values− A Boolean expression can define true or false values. Such Boolean expressions can be computed in parallel to arithmetic ... Read More