{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "## Reading Quiz 2\n", "\n", "Do the second DataCamp assignment, then finish the following exercises.\n", "\n", "Okay, now you know a bit more about R, let's put that to the test. Enter your name below:" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "#### NAME: " ] }, { "cell_type": "code", "execution_count": 1, "metadata": {}, "outputs": [ { "ename": "ERROR", "evalue": "Error in parse(text = x, srcfile = src): :1:7: unexpected symbol\n1: Emily Stewart\n ^\n", "output_type": "error", "traceback": [ "Error in parse(text = x, srcfile = src): :1:7: unexpected symbol\n1: Emily Stewart\n ^\nTraceback:\n" ] } ], "source": [ "Emily Stewart" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Problem 1" ] }, { "cell_type": "code", "execution_count": 9, "metadata": {}, "outputs": [], "source": [ "#here is a vector\n", "v<-c(3.4,4.2,0.7,2.0)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Use relational operators to make a vector of logicals which have the values of\n", "\n", "1) If `v` is greater than 1 and not 3.4\n", "\n", "2) if `v` is less than or equal to 2 or greater than 4\n" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# If `v` is greater than 1 and not 3.4\n", "\n", "\n", "# if `v` is less than or equal to 2 or greater than 4\n", "\n", "\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Problem 2\n", "Run the cell below:" ] }, { "cell_type": "code", "execution_count": 8, "metadata": {}, "outputs": [], "source": [ "### Run but DO NOT CHANGE\n", "require(oibiostat) #This loads standard datasets, you will see this a lot\n", "data(iris) #This loads the data from the iris data set\n", "df<-iris #this puts the iris dataframe into the variable df" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "`subset` the data in `df` so that only species which start with the letter \"v\" are included." ] }, { "cell_type": "code", "execution_count": 30, "metadata": {}, "outputs": [ { "data": { "text/html": [ "\n", "\n", "\n", "\n", "

Sepal.Length	Sepal.Width	Petal.Length	Petal.Width	Species

\n" ], "text/latex": [ "\\begin{tabular}{r|lllll}\n", " Sepal.Length & Sepal.Width & Petal.Length & Petal.Width & Species\\\\\n", "\\hline\n", "\\end{tabular}\n" ], "text/markdown": [ "\n", "Sepal.Length | Sepal.Width | Petal.Length | Petal.Width | Species | \n", "||\n", "\n", "\n" ], "text/plain": [ " Sepal.Length Sepal.Width Petal.Length Petal.Width Species" ] }, "metadata": {}, "output_type": "display_data" } ], "source": [ "subset(iris, Species== \"v\")" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Problem 3" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Make an ifelse loop that prints 'A' if `x` is less than or equal to 1, 'B' if `x` is bigger than 1 but less than or equal to 2, an 'C' otherwise." ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "### X\n", "x<-36+2/182-20\n", "##write the loop below this\n", "if (x<=1){'A'} else if (x<=2){'B'} else{'C'}" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Problem 4\n", "\n", "\n", "Alright, I'll walk you through this one a little. We are going to simulate a \"random walk.\"\n", "\n", "All this means is we want to plot a vector `X` which each entry is the previous entry $\\pm 1$ where we flip a coin to decide if it is $+$ or $-$.\n", "\n", "We will use the `sample` function to do this. In particular `sample(c(-1,1),1)` prints a number which is `-1` half the time and `1` the other half.\n", "\n", "Fill in the gaps in the loop below to make it produce a vector 100 entries long." ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "### This is some initializing: wer are setting our vector X to be the vector just containing 0\n", "X<-c(0)\n", "### Don't change this part, it is important for grading!\n", "set.seed(420)\n", "#\n", "### You need to fill in this next part....\n", "for(i _ _ _ _ ){ #edit this so that the \n", " delta<-sample(c(-1,1),1) #delta is either plus or minus 1 \n", " X[i+1]<- _ _ _ _ # fill this in according to the problem\n", "}\n", "#\n", "#\n", "#this will make a nice picture of what you just did\n", "plot(X)" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [] } ], "metadata": { "kernelspec": { "display_name": "R", "language": "R", "name": "ir" }, "language_info": { "codemirror_mode": "r", "file_extension": ".r", "mimetype": "text/x-r-source", "name": "R", "pygments_lexer": "r", "version": "3.4.4" } }, "nbformat": 4, "nbformat_minor": 2 }

Reading Quiz 2.ipynb