Publications by Dirk Hartog
Data 624_Project 1
library(tidyverse) ## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ── ## ✔ dplyr 1.1.4 ✔ readr 2.1.5 ## ✔ forcats 1.0.0 ✔ stringr 1.5.1 ## ✔ ggplot2 3.5.1 ✔ tibble 3.2.1 ## ✔ lubridate 1.9.3 ✔ tidyr 1.3.1 ## ...
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Data 624_Homework 6
library(tidyverse) library(fpp3) library(seasonal) library(fable) SECTION 9: ARIMA models EXERCISE 9.1 Figure 9.32 shows the ACFs for 36 random numbers, 360 random numbers and 1,000 random numbers. a. Explain the differences among these figures. Do they all indicate that the data are white noise? The first key differenece between each of these ...
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Data 624_Homework 5
library(tidyverse) library(fpp3) library(seasonal) library(fable) SECTION 8: Exponential smoothing Forecasts produced using exponential smoothing methods are weighted averages of past observations, with the weights decaying exponentially as the observations get older. EXERCISE 8.1 Consider the the number of pigs slaughtered in Victoria, availabl...
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Homework wk5
library(tidyverse) ## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ── ## ✔ dplyr 1.1.4 ✔ readr 2.1.5 ## ✔ forcats 1.0.0 ✔ stringr 1.5.1 ## ✔ ggplot2 3.5.1 ✔ tibble 3.2.1 ## ✔ lubridate 1.9.3 ✔ tidyr 1.3.1 ## ...
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Data 624_Homework 3
library(tidyverse) library(fpp3) library(seasonal) library(fable) EXERCISE 5.1 Produce forecasts for the following series using whichever of NAIVE(y), SNAIVE(y) or RW(y ~ drift()) is more appropriate in each case: a. Australian Population (global_economy) Time Series plot of Australian population aus_pop <- global_economy %>% filter(Country == "...
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DAT624_Homework 2
library(tidyverse) library(fpp3) library(seasonal) library(plotly) EXERCISE 3.1 Consider the GDP information in global_economy. Plot the GDP per capita for each country over time. Which country has the highest GDP per capita? How has this changed over time? head(global_economy,5) glimpse(global_economy) ## Rows: 15,150 ## Columns: 9 ## Key: Coun...
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Data 624_Homework 1
library(tidyverse) library(fpp3) EXERCISE 2.1 Explore the following four time series: - Bricks from aus_production - Lynx from pelt - Close from gafa_stock - Demand from vic_elec. a. Use ? (or help()) to find out about the data in each series. # read in the time series ?aus_production ?pelt ?gafa_stock ?vic_elec b. What is the time interval of ...
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Final Exam - Data 605
library(tidyverse) ## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ── ## ✔ dplyr 1.1.4 ✔ readr 2.1.5 ## ✔ forcats 1.0.0 ✔ stringr 1.5.1 ## ✔ ggplot2 3.4.4 ✔ tibble 3.2.1 ## ✔ lubridate 1.9.3 ✔ tidyr 1.3.1 ## ...
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Homework wk15
Question 1: Find the equation of the regression line for the given points. Round any final values to the nearest hundredth, if necessary. (5.6,8.8), (6.3,12.4), (7,14.8), (7.7,18.2), (8.4,20.8) library(tidyverse) ## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ─�...
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Discussion board 15
Chapter 12: Exercises 6 and 8 Evaluate \(f_x(x,y)\) and \(f_y(x,y)\) at the indicated point. We need to find the derivatives with respect to x and y separately and then evaluate them at the given point. 6. \(f(x,y) = x^3 - 3x + y^2 -6y ~at ~(-1,3)\) a. Partial derivative with respect to x \(f_x(x,y)\) \(\frac{df}{dx} x^3 - 3x + y^2 -6y\) Differen...
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