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Combined display of all available logs of Applied Science. You can narrow down the view by selecting a log type, the username (case-sensitive), or the affected page (also case-sensitive).

• 00:31, 23 April 2022 Wikiadmin talk contribs created page Conditions for differentiability for many variables (Created page with "For single variable functions we learn that being differentiable implies in being continuous. We also learn that being continuous doesn't imply in being differentiable because there are some exceptions to the rule. For multivariable functions differentiability also requires continuity, but we also have specific cases where we can calculate partial derivatives while the function is also discontinuous at a point. <math>f(x) = |x|</math>. This single variable example shows...")
• 19:17, 22 April 2022 Wikiadmin talk contribs created page Commented exercises (Created page with "* '''The two algorithms below attempt to calculate xn. However, both are wrong, explain the error in each one:''' <div style="margin-left:1.5em;"> {| class="wikitable" |<div class="code">for (i = 1; i <= n; i++) x = x * i;</div> || It's successively multiplying by an increasing counter. For x = 4, we have 4 * 1 * 2 * ... * n |- |<div class="code">for (i = 0; i < n; i++) x = x * x;</div> || It's squaring the number over and over n times. For x = 4, we have 42, then 162, t...")
• 18:14, 22 April 2022 Wikiadmin talk contribs created page Programming practices (Created page with "Some recommendations and small programming techniques are employed in the introduction. They are small details that do not determine whether you pass or fail, but are useful for learning purposes anyway. <div style="text-align:center;"> '''Comments''' </div> * All teachers recommend that you comment your programs, both because that counts for grading of the programming exercises, as well as because that makes your code more accessible for other people, or even yoursel...")
• 16:39, 22 April 2022 Wikiadmin talk contribs created page Characters and strings (Created page with "It's a common practice to teach how to use characters only after teaching how to operate with numbers and variables. This is done because characters are represented by numeric codes. There is one fundamental concept about how computers work. Deep down the computer works by doing elementary logic operations. That's very hard or very easy to grasp depending on the person. It's unnatural to think on words with logical operations. The algorithms that deal with characters ar...")
• 15:14, 22 April 2022 Wikiadmin talk contribs created page Random numbers (Created page with "For this introductory level, random numbers are not studied. They show up when we need to test programs with random inputs. To study algorithms that generate random numbers or the mathematical theory behind them is not a subject to be discussed at this stage. Random numbers do not obey to any law or formula, therefore they are impossible to be generated by any computer running some algorithm. The numbers that we see are pseudo-random, numbers that have a law of formatio...")
• 15:01, 22 April 2022 Wikiadmin talk contribs created page Dynamic memory allocation (Created page with "When variables and functions are created they go in the computer's memory. At this introductory level we ignore how memory is managed. We are assuming that it is correctly allocated and deallocated by the operational system. There is a whole class of algorithms that deal with memory management that we won't go in detail at this time. '''There are many natural questions that arise when we think about how the operational system handles memory:''' ''"Where in the memory a...")
• 00:19, 22 April 2022 Wikiadmin talk contribs created page Search and sort (Created page with "In this introduction we study the most elementary algorithms for searching and sorting. They are less efficient, but are easier to understand. The faster ones rely on more advanced knowledge that is beyond the objectives of this course. There are some probability theories behind such problems but we skip those for now. The usual way to tech these algorithms is by showing a sequence of values and performing a search or sort operation by hand. After that we attempt to tra...")
• 14:25, 21 April 2022 Wikiadmin talk contribs created page Struct data ype (Created page with "There are many situations in which many variables are related to each other, with the values stored in each variable are pieces of information belonging to one object or entity. It would be desirable to have a way to store that information in a cohesive way, without having to resort to using many unique variables with their relationship achieved through some programmer's defined naming convention. Fortunately, we have '''structs''' to allow us to link different data type...")
• 02:31, 20 April 2022 Wikiadmin talk contribs created page Introduction to recursive functions (Created page with "In the introduction to functions' chapter we learned that, in computing, the definition of a function borrows the mathematical definition. We also learned that, much like in mathematics, a function can call another function. If you have wondered if a function can call itself, you were right and that's called recursion. The question about recursive algorithm's performance vs non recursive algorithms is not studied in this course, that is left for later disciplines. For no...")
• 00:57, 20 April 2022 Wikiadmin talk contribs created page Functions, structs and pointers (Created page with "Pointers to struct provide a convenient way to access struct's members. The concept of pointers to struct is the same as pointer to any other variable: we first have to declare the variable and the pointer to it, then make the pointer point to that variable's memory address. The advantage of using pointers to structures is that in case we have a function that does something which requires data from a struct we don't have to pass all the struct's values to the function, j...")
• 20:23, 19 April 2022 Wikiadmin talk contribs created page Introduction to pointers (Created page with "In the simplest exercises and examples, about conditional structures, loops, arrays and matrices and functions, a pointer was not required to solve the problem. In some occasions the pointer showed up, like in the case of scanf() function, but the details about how it works were omitted to simplify and maker it easier to understand. Can a function calculate two values and return both? Calculate two different values yes, but return both no. That's when we need pointers....")
• 18:26, 19 April 2022 Wikiadmin talk contribs created page Functions that return a struct (Created page with "* '''Function that returns both roots of a second degree polynomial equation:''' <div class="code"> <span class="codecomment">Struct to store two values: </span><br /> struct roots { float x1, x2; }; <span class="codecomment">Function that receives the coefficients a, b and c and returns the roots of the second degree polynomial (it doesn't cover the case of a negative delta): </span><br /> Quadratic (int a, int b, int c) {<div style="margin-left:1.5em;"> struct...")
• 17:56, 19 April 2022 Wikiadmin talk contribs created page Functions, arrays and matrices (Created page with "After learning how to use functions, arrays and matrices, it's time to learn how to use arrays and matrices as function's parameters. A matrix with 10 columns and 10 rows can store up to 100 values, but a function doesn't make 100 calls when we use that matrix in that function. We can have a function with 100 parameters, but if they are all part of a matrix it's much simpler to just use the matrix and then reference to it by a single name. To explain why matrices and ar...")
• 01:26, 19 April 2022 Wikiadmin talk contribs created page Introduction to functions (Created page with "It's not really avoidable, functions in a program are analogous to functions in mathematics. During high (secondary) school we learn that <math>f(x) = x^2</math> is a function. Each <math>x</math> is associated with <math>x^2</math>. You should be familiar that a function can only be a function if, for each <math>x</math>, there is only one corresponding <math>y</math>. From the mathematical definition: a function can have different parameters and return the same result...")
• 14:52, 18 April 2022 Wikiadmin talk contribs created page Arrays and matrices (Created page with "''For some reason, in portuguese, the word "vetor" (vector in english) means both vector, the mathematical object, and array, the computing object. In C a matrix is a matrix for the user and the programmer who is not dealing with pointer arithmetic, but when pointer arithmetic is exposed, a matrix turns out be an "array of array".'' In the beginning of the introduction to computing discipline we learn what's the use of arrays and how to use one. The mathematical side of...")
• 13:52, 18 April 2022 Wikiadmin talk contribs moved page Repetition structures to Loops and repetition without leaving a redirect
• 13:43, 18 April 2022 Wikiadmin talk contribs moved page Iteration structures to Repetition structures without leaving a redirect
• 02:03, 18 April 2022 Wikiadmin talk contribs created page Iteration structures (Created page with "''"Computers never get tired and never complain"'' - Cute joke that my teacher used to make during the classes Initially, when we learn how to use loops, we don't worry about the performance of the algorithms. To study the performance of algorithms is left to later, more advanced, disciplines, where search or sorting algorithms are studied. However, we can already think about performance like this: one extra iteration and our algorithm is slower than another algorithm t...")
• 01:00, 18 April 2022 Wikiadmin talk contribs created page Switch case (Created page with "* '''Conditional structures with SWITCH and CASE:''' <div style="margin-left:1.5em;"> int choice;<br /> switch (choice) {<br /> case 1: printf("You chose 1"); break;<br /> case 2: printf("You chose 2"); break;<br /> case 3: printf("You chose 3"); break;<br /> default: printf("You chose %d (none of the above)", choice);<br /> } </div> '''Differences between SWITCH CASE and ELSE IF.''' The program's behaviour should be the same, what changes is the syntax and...")
• 00:43, 18 April 2022 Wikiadmin talk contribs created page Conditional operator (Created page with "* '''The same algorithm that tests if a number is odd or even, this time with the '?:' operator (ternary or conditional operator):''' int a;<br /> a % 2 == 0 ? printf("the number %d is even", a) : printf("the number %d is odd", a); The ''''?:'''' operator simplifies the ''''if else'''' statements into a single line of code, an expression formed through one conditional and two commands. There are two differences between using ''''if else'''' or the conditional operator:...")
• 23:59, 17 April 2022 Wikiadmin talk contribs created page If else (Created page with "* '''An algorithm that tests if a number is odd or even:''' <div style="margin-left:1.5em;"> int a; if (a % 2 == 0) printf("The number %d is even", a);<br /> else printf("The number %d is odd", a); </div> Pretty simple, just the part related to user input has been omitted. It's pretty intuitive the concept about decision making in examples such as this one. * '''A variation of the algorithm above, this time with the operators AND, OR plus ELSE IF:''' <div style="ma...")
• 23:03, 17 April 2022 Wikiadmin talk contribs created page Conditional structures (Created page with "One of the first things that you learn is how to make a computer receive a value, process it and return to you something. That's when we need the concept of flow control. You write something that controls the decisions (decisions that you make, not the computer) about what and when to execute something. The simplest flow control structure is IF ... ELSE. '''The basic logic is:''' do this if that is true, else do something else. On one hand you can choose that one case i...")
• 00:03, 16 April 2022 Wikiadmin talk contribs created page Tracking algorithms with pencil and paper (Created page with "In the introduction to computing course the teacher might write a lot on the blackboard and, the students, a lot on paper. The computer is left for homework, some of which, called program exercises, are graded and counted for the grade at the end of the semester. Some universities include practical classes in laboratories, some does not. The tests are not computer based, but in a old-fashioned way with paper and pencil. The teacher should not ask students to write a full...")
• 19:04, 14 April 2022 Wikiadmin talk contribs created page Introduction to C (Created page with "Because the discipline is an introduction, the algorithms studied doesn't use the most advanced features of C. A lot of things aren't studied in this course, just the most elementary to understand how a program is executed. Due to the similarities between mathematics and even spoken language, you just have to read a code carefully to understand the order of the operations. <div style="text-align:center;">'''A short summary about the C language'''</div> * '''Keywords....")
• 15:57, 14 April 2022 Wikiadmin talk contribs deleted page File:Extreme values graph2.png (Deleted old revision 20220414155740!Extreme_values_graph2.png)
• 15:57, 14 April 2022 Wikiadmin talk contribs uploaded a new version of File:Extreme values graph2.png
• 01:47, 14 April 2022 Wikiadmin talk contribs created page Pseudocode (Created page with "Writing code in a pseudo-language has two objectives in the course: first to eliminate all syntax and language's technical details. Second, to focus on logic and on the order of operations. Those who have already programmed before shouldn't have difficulties with pseudo-code. However, those who have never programmed before and have no idea about how the operations are processed by the computer, should have in pseudo-code an opportunity to not worry about a programming la...")
• 01:02, 14 April 2022 Wikiadmin talk contribs created page About introduction to computing (Created page with "The chapter order in here is similar to that of lectures given in a first semester of introduction to computing. In the first lectures the teaches describes the basic architecture of a computer, the fundamentals of input and output, without worrying about any technical specification such as clock, bits or memory amount. At this stage the focus is on understanding how the computer's logic functions by using a high level programming language. The low level and the algebra...")
• 17:42, 13 April 2022 Wikiadmin talk contribs moved page Graph of the parabola, exp and log to Graphs of the parabola, exp and log without leaving a redirect
• 16:00, 13 April 2022 Wikiadmin talk contribs created page Graphs of trigonometric functions (Created page with "==The sine and cosine waves== <div style="text-align: center;"> 500px (they aren't perfect sines or cosines because they were hand drawn) </div> '''Why are they waves?''' You need to understand the unit circle and how to read it. First, angles as we learn in euclidean geometry, are always in between 0° and 360°. That is, from zero to doing a full circle turn. Any angle beyond that is just multiples of full turns or partial turns. With negati...")
• 15:56, 13 April 2022 Wikiadmin talk contribs moved page Graph of single variable functions to Graph of the parabola, exp and log without leaving a redirect
• 00:53, 13 April 2022 Wikiadmin talk contribs created page Mistakes regarding graphs (Created page with "* Crescent, decrescent and constant functions. First, for languages that are written right to left this may be a source of confusion in comparison to languages that are left to right. The other is about reading the graph itself. It my happen that some people associate in their minds ''"positiveness"'' with a function being crescent and ''"negativeness"'' with being decrescent. While ''"null"'' would mean constant. Yet another source of confusion is to think that concavit...")
• 21:00, 11 April 2022 Wikiadmin talk contribs created page File:Radian.png
• 21:00, 11 April 2022 Wikiadmin talk contribs uploaded File:Radian.png
• 17:39, 11 April 2022 Wikiadmin talk contribs created page Radians (Created page with "One radian is the angle at which the arc's length of the circle is equal to its own radius. How many times does the radius fit into the circle's perimeter? Ans: <math>2\pi</math> times for a radius of one. That is ~6.28.... a real number. This ratio is the same for circles of any radius, it's a constant. If the perimeter of the circle with a radius of one is <math>2\pi</math> and one full turn is 360°, there is our conversion formula between radians and degrees. 180°,...")
• 23:59, 10 April 2022 Wikiadmin talk contribs uploaded a new version of File:Parametric line.png
• 23:05, 10 April 2022 Wikiadmin talk contribs deleted page File:Parametric circle.png (Deleted old revision 20220410230503!Parametric_circle.png)
• 23:05, 10 April 2022 Wikiadmin talk contribs uploaded a new version of File:Parametric circle.png
• 23:02, 10 April 2022 Wikiadmin talk contribs created page File:Parametric line.png
• 23:02, 10 April 2022 Wikiadmin talk contribs uploaded File:Parametric line.png
• 22:58, 10 April 2022 Wikiadmin talk contribs created page File:Parametric circle.png
• 22:58, 10 April 2022 Wikiadmin talk contribs uploaded File:Parametric circle.png
• 22:58, 10 April 2022 Wikiadmin talk contribs deleted page File:Parametric parabola.png (Deleted old revision 20220410212416!Parametric_parabola.png)
• 21:24, 10 April 2022 Wikiadmin talk contribs uploaded a new version of File:Parametric parabola.png
• 19:43, 10 April 2022 Wikiadmin talk contribs created page File:Parametric parabola.png
• 19:43, 10 April 2022 Wikiadmin talk contribs uploaded File:Parametric parabola.png
• 16:56, 8 April 2022 Wikiadmin talk contribs created page Derivative of inverse functions (Created page with "When we do a composition of a function and its inverse the result is that we do some operation, undo it with the reversed operation, which results in the output and the input being equal to each other. In mathematical notation: <math>f(f^{-1}(x)) = x</math>. For now we skip the conditions for which a function is invertible. To make the proof easier to read let's write <math>f^{-1}(x) = g(x)</math>: The rate of change of <math>x</math> is trivial, it's 1. If <math>\frac{...")
• 21:16, 7 April 2022 Wikiadmin talk contribs created page Change the base of a logarithm (Created page with "Logarithms are pretty natural when it comes to powers of two, powers of three and other common powers. If we have <math>2^x = 5</math> we know that <math>2^2 = 4</math> and that <math>2^3 = 8</math>. For <math>2 < x < 3</math> there must be some number such that raising 2 to that number yields exactly 5. The interesting property here is that we can also write <math>3^y = 5</math>, which means that the number 5 can be written as many different logs with different bases ea...")
• 23:06, 6 April 2022 Wikiadmin talk contribs created page File:Euler constant graph.png
• 23:06, 6 April 2022 Wikiadmin talk contribs uploaded File:Euler constant graph.png