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<p><font size="+1">Last week we discussed the idea of doing challenge problems in R group.</font></p>
<p><font size="+1">Here is the challenge problem for Friday Nov 1.</font></p>
<p><font size="+1">Beginner Mode) <br>
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<p><font size="+1">Write R code to test if a vector of numbers is increasing or decreasing. Test you code to make sure it works.</font></p>
<p><font size="+1">R User Mode)</font></p>
<p><font size="+1">Write R functions to test if a vector is increasing, decreasing, non-increasing or non-decreasing. Write test code for the functions.</font></p>
<p><font size="+1">Power User Mode)</font></p>
<p><font size="+1">Write an R function to test if a vector is monotonic, if it is monotonic, then it should also indicate whether the vector is increasing or decreasing. Write test cases.</font></p>
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<p><font size="+1">I'll create a discussion board for these.<br>
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<p><font size="+1">This problem actually came up in something I was doing, so I have solutions to share.<br>
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<p><font size="+1">-------</font></p>
<p><font size="+1">After that, I'm going to look into building exercises using R Markdown. Maybe we can turn Wenyi's ggplot talk into an interactive tutorial.</font></p>
<p><font size="+1"> --Russell</font></p>
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