gibson:teaching:fall-2013:math445:hw1
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gibson:teaching:fall-2013:math445:hw1 [2013/09/05 11:28] gibson created |
gibson:teaching:fall-2013:math445:hw1 [2013/09/06 11:55] (current) gibson |
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| + | Selected problems from Attaway 3rd edition, chapters 1 and 2. | ||
| **Problem 1:** Create the following vectors twice, once using **linspace** and once using the colon operator. | **Problem 1:** Create the following vectors twice, once using **linspace** and once using the colon operator. | ||
| Line 11: | Line 11: | ||
| **Problem 3:** Given a vector //v// of arbitrary length, write an expression that evaluates to the odd-numbered elements of //v//. Test your expression on vectors //v// of both even and odd length. | **Problem 3:** Given a vector //v// of arbitrary length, write an expression that evaluates to the odd-numbered elements of //v//. Test your expression on vectors //v// of both even and odd length. | ||
| - | **Problem 4:** Given a vector //v// of arbitrary length, write assignment statements that store the first half of //v// in a vector //v1// and the second half in a vector //v2//. Make sure your assignment statements work for //v// of both even and odd length. Hint: use a rounding function such as **fix**. | + | **Problem 4:** Given a vector //v// of arbitrary length, write assignment statements that store the first half of //v// in a vector //v1// and the second half in a vector //v2//. Make sure your assignment statements work for //v// of both even and odd length. |
| **Problem 5:** Create a 4 x 2 matrix of all zeros and store it in a variable. Then replace the second row of the matrix with a 3 and a 6. | **Problem 5:** Create a 4 x 2 matrix of all zeros and store it in a variable. Then replace the second row of the matrix with a 3 and a 6. | ||
| Line 17: | Line 17: | ||
| **Problem 6:** Create a 3 x 5 matrix of random real numbers, and then delete the third row. | **Problem 6:** Create a 3 x 5 matrix of random real numbers, and then delete the third row. | ||
| + | **Problem 7:** What are the values of the following expressions? Explain why. | ||
| + | 'c' == 'd' - 1 && 2 < 4 | ||
| + | 'c' == 'd' - 1 || 2 < 4 | ||
| + | xor('c' == 'd' - 1, 2 < 4) | ||
| + | 10 > 5 > 2 | ||
| + | | ||
| + | **Problem 8:** The value of $\pi^2/6$ can be approximated by the sum of the series | ||
| + | |||
| + | <latex> | ||
| + | 1 + 1/2^2 + 1/3^2 + 1/4^2 + \ldots | ||
| + | </latex> | ||
| + | |||
| + | Write a one-line Matlab expression that evaluates the sum for the first $n$ terms. Test it for a few values of $n$ and compare to $\pi^2/6$. | ||
| + | |||
| + | **Problem 9:** A vector //v// stores hours worked and hourly wages sequentially for a number of employees. For example | ||
| + | |||
| + | <code> | ||
| + | v = [33 10.5 40 18 20 7.5] | ||
| + | </code> | ||
| + | |||
| + | would specify three employees, the first working for 33 hours at %%$10.50/hr%%, the second 40 hours at %%$18/hr%%, etc. For an arbitrarily long //v//, write code that would separate //v// into an //h// vector of hours worked and a //r// vector of hourly wage rates, and then compute a //w// vector of wages owed to each employee. Do this as compactly as possible. | ||
| + | |||
| + | |||
| + | **Problem 10:** Evaluations at a university are scored 1-5, bad to good. However the evaluation forms mistakenly say that 1-5 is good to bad. So the computer program written to analyze evaluations must "reverse" all the evaluation scores. That is, | ||
| + | |||
| + | evals = [5 3 2 5 5 4 1 2] | ||
| + | | ||
| + | should really be | ||
| + | |||
| + | evals = [1 3 4 1 1 2 5 4] | ||
| + | | ||
| + | Write Matlab code that will reverse an arbitrary //eval// vector to the correct 1-5 scale. | ||
gibson/teaching/fall-2013/math445/hw1.1378405692.txt.gz · Last modified: 2013/09/05 11:28 by gibson
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