Publications by Tasneem Zaihra

Poisson Model Univariate vs Multivariate

11.01.2024

Multivariate Analysis mv.model = glm(hospitalizations ~ sex+cesd+age, data = HELPrct, family = "poisson") summary(mv.model) ## ## Call: ## glm(formula = hospitalizations ~ sex + cesd + age, family = "poisson", ## data = HELPrct) ## ## Deviance Residuals: ## Min 1Q Median 3Q Max ## -3.7643 -1.7065 -0.8024 0.1558 ...

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Chapter5 Computing Assignment

07.04.2020

Exercise 5.1 You can create a function to evaluate the MC estimate of the integral \(\int_{0}^{\pi/3} sin(t) dt\) and compare your value with the exact integral value, i.e., 0.5. Also, you should be able to demonstrate that by taking larger samples we reduce the error of our estimation and thus have a better estimate to the true integral value. e...

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Ch5 Computing Lab: Nuts and bolts of Simulation

28.03.2020

loading Packages require(latticeExtra) require(mosaic) require(Hmisc) Example1: Simulating Sampling Distribution of Mean for three different sample sizes, n=5, n=25 and n=100 from expoential distribution with mean 5 and visualising it using boxplots lambda<-2 numsim<-100 mean5<-rep(0,numsim) mean25<-mean5 mean100<-mean5 for (i in 1:numsim){ m...

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Ch2_CLT_Lab

18.02.2020

Problem2: Data/Sample generated from Normal Distribution set.seed(1234) true_mean <- 0 true_var <- 1 n <- 10 reps <- 10 cat("For a normal distribution with a mean of", true_mean, "and a variance of", true_var, "\nWith n =", n, "we should obtain a sample mean of", true_mean, "and a sample variance of", true_var/n,"\n") ## For a normal distribution...

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ECDF_Quantiles

13.02.2020

require(moaic) require(dplyr) The e.c.d.f. (empirical cumulative distribution function) Fn is a step function with jumps i/n at observation values, where i is the number of tied observations at that value. Missing values are ignored. or observations x= (x1,x2, … xn), Fn is the fraction of observations less or equal to t, i.e., \[ Fn(t) = #{xi <...

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Introduction to R n RStudio by Dr. Zaihra part1

29.09.2020

Using RMarkdown Text Text can be decorated with bold or italics. It is also possible to create links include mathematics like \(e=mc^2\) or \[y = \beta_0 + \beta_1 x_1 + \beta_2 x_2\] Be sure to put a space after the * when you are creating bullets and a space after # when creating section headers, but not between $ and the mathematical formul...

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Nuts and Bolts of R and RStudio Part2

29.09.2020

knitr settings to control how R chunks work. require(knitr) opts_chunk$set( tidy=FALSE, # display code as typed size=“small” # slightly smaller font for code ) The most important template is goal(y~x,data=mydata) What you want R to do is Goal : This determines the function to use(favstat, mean, SD, lm) What must R know to do that: This dete...

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Merge_Create_Reorder_Categories

21.10.2020

Creating a random data frame, with two columns a== factor with 5 levels and B is numeric coming from normal distribution. set.seed(1234) # to keep the random variables generated fixed for every rerun to trace errors df <- data.frame(a = LETTERS[sample(5, 15, replace=TRUE)], y = rnorm(15)) df ## a y ## 1 A 0.98340378 ## 2 D -0.622...

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DownstateTalk

05.01.2021

Chunk where you install and/or load all necessary packages Vitamin C example’s contingency table and chi-square test ski.reg<-matrix(c(31, 17, 109, 122), ncol=2, dimnames=list(Treatment=c("Placebo", "VitaminC"), Cold=c("Cold", "NoCold"))) ski.reg %>% kbl(caption = "French Skiers Regular") %>% kable_classic(full_width = F, html_font = "Camb...

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Categorical Graphs exploring Moderation

24.11.2020

require(mosaicCore) require(mosaicData) require(ggplot2) Improting one of the many mosaic data https://cran.r-project.org/web/packages/mosaicData/mosaicData.pdf head(HELPrct) ## age anysubstatus anysub cesd d1 daysanysub dayslink drugrisk e2b female ## 1 37 1 yes 49 3 177 225 0 NA 0 ## 2 37 ...

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