equal
deleted
inserted
replaced
306 |
306 |
307 \[ |
307 \[ |
308 \frac{price_{new} - price_{old}}{price_{old}} |
308 \frac{price_{new} - price_{old}}{price_{old}} |
309 \] |
309 \] |
310 |
310 |
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311 If the change factor is defined, you should return it |
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312 as \texttt{Some(change factor)}; if not, you should return |
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313 \texttt{None}. |
311 |
314 |
312 \item[(2.b)] Write a function that calculates all change factors |
315 \item[(2.b)] Write a function that calculates all change factors |
313 (deltas) for the prices we obtained under Task 1. For the running |
316 (deltas) for the prices we obtained under Task 1. For the running |
314 example of Google and Apple for the years 2010 to 2012 you should |
317 example of Google and Apple for the years 2010 to 2012 you should |
315 obtain 4 change factors: |
318 obtain 4 change factors: |
318 List(List(Some(-0.03573992567129673), Some(0.5399749442411563)) |
321 List(List(Some(-0.03573992567129673), Some(0.5399749442411563)) |
319 List(Some(0.10103412653643493), Some(0.2477771728154912))) |
322 List(Some(0.10103412653643493), Some(0.2477771728154912))) |
320 \end{verbatim} |
323 \end{verbatim} |
321 |
324 |
322 That means Google did a bit badly in 2010, while Apple did very well. |
325 That means Google did a bit badly in 2010, while Apple did very well. |
323 Both did OK in 2011.\\ |
326 Both did OK in 2011. Make sure you handle the cases where a company is |
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327 not listed in a year. In such cases the change factor should be \texttt{None} |
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328 (see 2.a).\\ |
324 \mbox{}\hfill\mbox{[1 Mark]} |
329 \mbox{}\hfill\mbox{[1 Mark]} |
325 |
330 |
326 \item[(3.a)] Write a function that calculates the ``yield'', or |
331 \item[(3.a)] Write a function that calculates the ``yield'', or |
327 balance, for one year for our portfolio. This function takes the |
332 balance, for one year for our portfolio. This function takes the |
328 change factors, the starting balance and the year as arguments. If |
333 change factors, the starting balance and the year as arguments. If |